VILLANOVA UNIVERSITY DEPARTMENT OF MECHANICAL ENGINEERING

ME 362-4801: DESIGN SEMINAR

FINAL REPORT

DESIGN OF A HYBRID CAR C. R. Adcock C. A. Ayers T. J. Grisillo

K. M. Heselpoth I. A. Kirillov

K. V. McCauley (Team Leader)

April 16th , 2007

DESIGN OF A HYBRID CAR

by C. R. Adcock _______________________ C. A. Ayers _______________________ T. J. Grisillo _______________________ K. M. Heselpoth _______________________ I. A. Kirillov _______________________ K. V. McCauley _______________________

FINAL REPORT

Submitted to:

Department of Mechanical Engineering Villanova University Villanova, PA 19085

In partial fulfillment of the requirements for Design Seminar in Mechanical Engineering

April 16, 2007 Received by _________________________ Date_____________

ABSTRACT

The goal of the project was to make a functional hybrid car that runs on electric and diesel power. The vehicle will begin by using electrical power then be manually switched to the diesel engine by the driver of the vehicle. A DC electric motor would need to be running in parallel with a diesel engine. Eight car batteries, placed in series with one another inside the trunk of the car, will power the DC motor taking the place of a battery pack in a standard hybrid car. Other designs would be applied to help the efficiency of the car. This includes the design of a bio-diesel fuel as well as changing the exterior and interior design of the car.

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TABLE OF CONTETS Section Page ABSTRACT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v 1. EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. BACKGROUND INFORMATION AND DESIGN OBJECTIVES . . . . . . . . . . . . . . . . 4 4. TECHNICAL APPROACH AND DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1 Interior/Exterior Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1.1 Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1.2 Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1.3 Stripping the Car . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1.4 Exterior and Hatchback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1.5 Fiberglass Trunk Lid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.2 Bio-Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.1 Making a Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.2 Testing Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.2.3 Final Design and Other Considerations . . . . . . . . . . . . . . . . . . . . . . . . 13 4.3 Motor Placement – Transmission – Switching Mechanism . . . . . . . . . . . . . . . 13 4.4 Battery Mounts and Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.4.1 Preliminary Design . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.4.2 Final Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.5 Electrical Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 20 4.5.1 Electrical Subsystem Design Overview . . . . . . . . . . . . . . . . . . . . . . . . 20 4.5.2 Electrical Subsystem Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.5.3 Testing and Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5. COST ANALYSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6. CONCLUDING REMARKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 APPENDIX A. Brookfield Viscometer Test Results .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 APPENDIX B. Calculation of Diesel Dynamic Viscosity. . . . . . . . . . . . . . . . . . . . . . . . . . . 30 APPENDIX C. Brookfield Viscometer Test Results .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

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APPENDIX D. 3D Model Showing Flexible Coupling and Location. . . . . . . . . . . . . . . . . . 32 APPENDIX E. Dimensioned 3D Model of Adapter Plates. . . . . . . . . . . . . . . . . . . . . . . . . . 32 APPENDIX F. Drawing of Sprag/Overrunning Clutches . . . . . . . . . . . . . . . . . . . . . . . . . . .33 APPENDIX G. Free Body Diagram of Overrunning/Sprag Clutches . . . . . . .. . . .. . . . . . . . 33 APPENDIX H. 3D Model Highlighting Location of Overrunning Clutches. . . .. . . . . . . . . 34 APPENDIX I. Finite Element Analysis of Stress on Gears…. . . . . . . . . . . . . . . . . . . . . . . . 35 APPENDIX J. Top View of Trunk Area Preliminary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 APPENDIX K. Top View of Trunk Area Final . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 APPENDIX L. Top View of Battery Housing Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 APPENDIX M. Trunk Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 APPENDIX N. Trunk Spacing Continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 APPENDIX O. Tour Del Sol Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 APPENDIX P. Acceleration Charts and Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 APPENDIX Q. Electrical Range vs. Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 APPENDIX R. 120V System Using 10x 32 Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 APPENDIX S. Electrical Schematic . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 APPENDIX T. Wire Sizing Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

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LIST OF TABLES

Table Title Page 1 Cost Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2 BrookField Viscometer Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3 Data for Acceleration Graphs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 4 96V System Using 8x 55 Ah Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

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LIST OF FIGURES Figure Title Page 1.1 Battery Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3.1 EPA Emission Findings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Toyota Prius Battery Pack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1.1 Interior Layout of Car after Stripping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1.2 Layout with Dashboard Removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1.3 Trunk Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.1.4 Layout of Trunk With Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.2.1 Fuel and Glycerin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.2.2 From Grease to Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.4.1 Available Space in Trunk of Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.4.2 Battery Placements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.4.3 Battery Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.4.4 Finished Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.5.1 Advanced 4001 Series 8” DC Motor Cutaway Illustration . . . . . . . . . . . . . . . . . 21 4.5.2 Curtis 1221c DC Motor Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.5.3 Albright SW200a Contactor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.5.4 MK 8A22NF Deep-Cycle Lead-Acid Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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1. EXECUTIVE SUMMARY

The main challenge in building the hybrid car was devising a system that could alternate

between the diesel engine and the electric motor. Before this system could be developed the transmission chosen for the project was broken down so its internal gears and shafts could be observed. Once this was achieved the idea for

To be certain bio-fuel can be used a sample was created. This required a titration test to determine how much NaOH must be dissolved in the Methanol to create a successful transesterification. Once the bio-fuel was created it was tested for its flammability, viscosity, and freezing points. The fuel did burn and indicates that its emissions will be close to EPA standards. Also the viscosity and freezing point were measured at -2 C and 18.9*10-3 Pa*s respectively. The simplest way of using the bio-fuel is splicing it with diesel in an 80%/20% configuration of bio-fuel to diesel. This will see a loss of the bio-diesels lower hydrocarbon emissions, but will nearly negate the increase in Nox.

The electric power will be generated from 8 12V MK 822NF Deep Cycle Lead-Acid Batteries in series generating 96V. This 96V is then constantly sent to the Curtis 1221c DC Motor Controller which will serve as the interface between the battery bank and the Advanced 4001 series 8” DC electrical motor itself. The control will serve as a speed regulator with a 5KΩ lever operated potentiometer serving as the throttle input to the controller. When the vehicle stopped, the inputs to the controller are 96V and the potentiometer is at a full 5KΩ . The resulting voltage being transmitted to the DC Motor is 0V. As the potentiometer is lowered, more voltage is being transmitted to the DC motor resulting in the vehicle speeding up. An Albright CT-SW200 DC contactor would serve as a specialized relay between the battery bank and the DC controller in order to ensure that the high current (some as high as 200 Amps) demands of the electrical motor would be sufficiently met.

It was decided to house the batteries in the rear of the vehicle. Specialized box housings were designed and constructed to hold the batteries in place. Each box was constructed of quarter inch plywood, with an inner lining of 1/8” polypropylene to provide insulation in case of an unwanted electrical discharge. The placement of these batteries is shown in the figure below.

Figure 1.1: Battery Placement

A design had to be made to lessen the angle of the slope on the trunk because the current

trunk had a steep slope of 68 degrees. This was accomplished by making a hatchback trunk. With a difference of 20 degrees in the slope between the old trunk and the new hatchback trunk, the hatchback trunk provides a drop in the drag force and an increase in the efficiency of the vehicle. It would be made of fiberglass mats covered in resin, with a Plexiglas window for the driver. A few design ideas were drawn up for the basic layout of the hatchback trunk as well as the materials used, but it was finally decided to use a fleece sheet underneath the fiberglass. The trunk would encompass the rear window as well as the trunk area. The hatchback trunk is near completion, with just the Plexiglas window and weather-stripping tubing to be added.

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2. INTRODUCTION The goal of the design team at the outset of this endeavor was to design and build a fully operational hybrid vehicle. This entailed several stages of development and implementation. In the preliminary stages of the project, background and state-of-the-art research was the primary focus. Next, preliminary designs were drawn up based on the research conducted. Last, the designs were implemented and often revised. Within this structure, the project was dissected into several subprojects, including production of bio-fuel, design and placement of the electrical components of the vehicle, refurbishing the interior of the vehicle, improving the aerodynamics, and designing a transmission that accommodates switching between electric and engine power. With ever rising energy costs, the necessity and demand for alternative energy sources is consistently rising. The following report contains a detailed analysis of the course of action taken by the design team in meeting the various design goals.

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3. BACKGROUND INFORMATION AND DESIGN GOALS

Hybrid cars have recently come into public notice. Rising costs of crude oil are driving

oil prices higher with each passing month. There is great interest in providing alternate fuel and power methods for public transportation. Similarly public awareness has brought the ideas of being eco-friendly and sustainable to the forefront of many prominent research companies. With this in mind the idea for a bio-fueled Hybrid vehicle was generated.

Hybrid vehicles are essentially a combination of a gasoline powered and electric powered vehicle. In gasoline powered engines, the maximum horsepower is only used about one percent of the time. The main function of the 100 or more horsepower is to generate enough power to accelerate the vehicle from rest. The engine might only need to produce ten to twenty horsepower to maintain cruising speeds. In general, hybrid vehicles contain an electric motor and batteries to power the motor. In addition, the vehicle has a small gasoline engine which is used to run at one speed for maximum efficiency. The main purpose of the engine is to provide the necessary power for cruising. During acceleration the electric motor aids the small engine. This results in increased gas mileage.

When the project first started, a Triumph TR-7 was provided. Many adjustments had to be made to the basic structure of the car to fit what the needs of the project. These changes would encompass both the interior and the exterior of the car and would make the car more suitable to the design goals, primarily to reduce the weight of the car as well as make it more aerodynamic to increase the fuel efficiency of the car. The original intention of the project was to enter the car into the Tour de Sol race held in New York every May. This race included many competitions, such as a long distance race, an emissions test, and a speed race to name a few. In order to be able to fully compete in this race, the interior and exterior of the car had to be modified. The main focus was on the exterior of the car, but a few modifications were made to the interior of the car as well.

To help reduce harmful emissions bio-diesel was chosen to power the engine. Bio-diesel is formed from vegetable oils by a process known as transesterification. This process removes the glycerin part of the vegetable oil. Doing so allows the vegetable oil to be used in diesel combustion engines. The sale of bio-diesel in the in the US is tracked by the National Bio-diesel Board. Since 1999 the volume of sales has increased from 500,000 gallons, to 75 million gallons in 2005.[1] The National Bio-diesel Board published there average emissions for vehicles running bio-diesel. These numbers allowed for estimation of the fuel’s performance in the hybrid vehicle.

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Figure 3.1: EPA Emission Findings[1] As can be seen, straight bio-diesel has a 48% decrease in Carbon Monoxied emissions and 67% in Total Unburned Hydrocarbons. These two facets are important because they represent incomplete combustion. The fuel does have a noticeably higher Nox emission, but when spliced with diesel fuel this is usually reduced.

When the project was begun, the electrical engineers did not have any experience in the design or manufacturing of Hybrid vehicles. After some research was done on www.consumersearch.com, it was then known that the best Hybrid vehicle on the market was the Toyota Prius. “The Toyota Prius remains the undisputed best among hybrid cars, say reviews, with an electric motor assisted by a gasoline engine. At city-driving speeds, the electric motor operates alone, and the gas engine kicks in at higher speeds.” The vehicle was then going to be modeled after the Toyota Prius. The initial electrical setup on the vehicle was going to consist of using a Toyota Prius Battery pack as seen below. Due to cost limitations for the project a Toyota Prius battery pack could not be attained. A used battery pack would cost approximately $3000 or more.

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Figure 3.2: Toyota Prius Battery Pack

The engine design for the vehicle was modeled after the Prius. According to www.about.com “Full hybrids integrate the electric motor, gas engine and battery so that the electric motor can operate on its own when certain conditions are met. The Prius does this under low speed, and once the vehicle reaches higher speeds, the gasoline engine starts up and takes over. Under hard acceleration, both the gas engine and the electric motor can work together to provide the needed power. Unlike mild hybrids, full hybrids are able to generate and consume electricity at the same time. The vehicle would follow the same model as the Prius. It would run on electric power for lower speed then the gasoline motor would start up and take over. The only difference is that out vehicle would not automatically transfer from electric to gasoline power; the driver would have to manually switch from the electric motor to the diesel engine. This was done due to cost and technology limitations. Design Goals for the Hybrid Vehicle

• Convert a 1976 Triumph TR-7 into a hybrid vehicle. Hybrid means using a system of electric/solar power and regular diesel or alternative gases for power.

• Keep the vehicle weight under 5000 lbs • Travel at least 50 mph on a level road. • Be driven 200 miles before the race • The vehicle must maintain a speed of 30 mph up a 10% grade. • Must be able to drive up an incline of 15%, come to a full stop, and resume

movement. • Optimize emission outputs, achievable speeds, fuel consumption rate and

overall efficiency of the vehicle to be competitive in the Tour del Sol.

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4. TECHNICAL APPROACH AND DISCUSSION

4.1 Interior/Exterior 4.1.1 Interior The very first task that was to be accomplished was to strip the car out on the inside to see what we had to work with and find any possible ways of reducing the cars weight. Since none of the group had any prior knowledge of the Triumph TR7, it was decided to take a better look to see what was under the hood, inside the dash and other interior components, and check out the trunk set up. The first step was to find a way to try to reduce the weight of the car. Reducing the weight of the car would help conserve fuel energy. 4.1.2 Dashboard To go about this task, the interior of the car was stripped. Everything was removed for the time being, including the car seats, dash board, and carpeting. Some of the inner components of the dash board were permanently removed to reduce the weight. When the dashboard is reassembled, a manual switch will be added to change between electric power and diesel power. The switch will be hooked up to the potentiometer, which controls the throttle that is linked to the DC motor. When the switch is turned off, it will cut off power to the throttle completely. When this happens, the power will come from the DC motor. The idea behind this is that the electric motor will be used to start up and get the car to a certain speed, and after this speed the diesel motor will be used to power the car. This in effect will conserve fuel and not drain the battery power too much. If the batteries were used to maintain speed, they will be drained too fast and in turn be inefficient. No modifications were added to renew the battery power, so this switch is what will be conserving their energy. 4.1.3 Stripping the car

Figure 4.1.1 shows what was left of the interior after the stripping out the flooring and the seating of the car.

Figure 4.1.1: Interior layout of car after stripping

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This freed up a lot of room to continue to do more work on the interior of the car. After removing the seats, the question came up of whether to buy new seats or keep the old ones. After doing research and looking up costs for racing seats, it was determined that the cost of replacing the seats would not justify reducing a few extra pounds. Prices for racing seats ranged from $200-$600 for two seats (1) and would only slightly reduce the weight for the seats. Figure 4.1.2 shows what was left after the dashboard was removed.

Figure 4.1.2: Layout of interior with dashboard removed

As stated earlier, much of the dash interior was removed for weight purposes. There was not much that could be removed, though. The car still had to be kept street legal so some of the equipment had to be kept in the car. As stated earlier, though, weight removal was not going to be the primary method to increase our fuel efficiency. Given the size and weight of the car, there was not much that could be removed to while keeping the car street legal and operational. Because of this, other methods had to be thought out to help the fuel efficiency. 4.1.4 Exterior and Hatchback Reducing the weight would help our overall efficiency, but it was not the biggest problem that was faced in this area. The main focus for conserving fuel energy in the car was on the trunk area. Figure 4.1.3 shows the back slope of the Triumph.

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Figure 4.1.3: Trunk layout

As can be seen by figure 3, the back slope for the Triumph is not aerodynamic and could cause a loss in fuel efficiency. Due to the steep slope caused from the trunk, the air flow over it would cause a drag over the back of the car, which would reduce the fuel efficiency since more power would have to be used to overcome this drag force. The slope of the trunk in its current state is 68 degrees. This slope angle was determined from the dimensions of the trunk and the following equation:

)15

5.5(cos 1−=m Equation 4.1

Where 5.5in is the base of the trunk and 15in is the slope length of the trunk. This slope angle is too steep and a design had to be implemented to reduce the slope angle to reduce the drag force. In order to do this, it was decided to make a new trunk for the back of the car. It would be a hatchback trunk, covering the original trunk, as well as the windshield area. This would reduce drag force from the air flow. While designing the hatchback trunk, a few things had to be kept in mind. First, the trunk itself had to be lightweight. It would be counterproductive to make a heavy trunk made of steel or some other metal material that would just add extra weight that we had already taken out earlier. Next, the trunk had to not only cover up the windshield part, but it also had to cover the original trunk space as well. The original trunk mounting was going to be removed in place of

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this hatchback. Finally, the trunk had to make room for a lightweight window for the driver to be able to see. All of these goals had to be kept in mind in making the final design. 4.1.5 Fiberglass Trunk Lid To account for the weight, fiberglass was to be used with a fleece sheet for support. Fiberglass is a composite material formed out of glass fibers. It takes the strong properties of glass but is not as brittle as glass. It is a good structural support as well as a good insulator. The fiberglass strands need to be hardened using resin and liquid hardener. Then it becomes a light weight, strong support structure. (2)

Applying a few layers of fiberglass would make a hard enough trunk support to protect the car while remaining very lightweight. The trunk design chosen is shown in Figure 4.1.4

Figure 4.1.4: Layout of trunk with dimensions

The green bars represent the steel frame that would be a rough guide to lay down the fiberglass and fleece cloth. With this design, the slope was reduced to 42 degrees, which is more than a 20 degree difference than before. This measurement was found through the following equation:

)45.3473.25(cos 1−=m Equation 4.2

Where 25.73in is the base length and 34.45in is the slope length.

As can be seen in figure 4, the frame encompasses both the backseat window area and the trunk space. The actual fiberglass trunk would also encompass the side areas as well to completely seal off the trunk from the outside. This is important since the trunk houses all ten

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batteries in the car, and any outside elements could cause serious damage if they were to interfere with the batteries. Finally, Plexiglas was chosen to be the window frame for the trunk. An area in the fiberglass hatchback would be cut out to insert the Plexiglas in. There are dangers with working with fiberglass, though. All necessary precautions were taken when working with the fiberglass mats and resin. The design that was to be used was one layer of a fleece sheet covered in resin covered by three layers of fiberglass. This process is currently still in progress, so more layers may be added if the hatchback is not considered sturdy and strong enough to fit our purposes. A second and third layer of fiberglass was not placed on the section where the Plexiglas would go. This would make the final cutting process to insert the Plexiglas much easier. The trunk is still in the process of being made, but is in the final stages. All three layers have been laid on, and after considerable sanding it will be determined whether or not more layers need to be laid on. A hinging system for the trunk is still being worked up. The trunk will be hinged to inside roof of the car and will have a latch at the bottom just like the old trunk had. The type of hinges to be used is still undetermined. Weather-stripping will also be added along the side of the trunk to make it completely sealed off from the outside. 4.2 Bio-Fuel 4.2.1 Making a Sample

First used grease was obtained from a local source. This was filtered to remove particles left from frying food. For the small sample required, coffee filters were used to separate the particles. A stock solution was created by dissolving 1g of sodium hydroxide (NaOH) in 1 L of distilled water. 10 mL of 99.5% Isopropyl alcohol was then added to 1 mL of clean grease, along with 2 drops of phenolphthalein. The grease solution was heated until the grease dissolved, and achieved a yellow tinged color. Using a burette, the stock solution was slowly added to the grease solution until the grease solution achieved a pink hue. 3.5 was added to number of mL of stock solution added during the titration. The resulting number was the grams of NaOH that must be added to every L of grease. The methanol (MeOH) added was established at 12% of the total grease volume.

Using the numbers found in the titration experiment it was determined that 500 mL of grease could be mixed with 2.2g of NaOH and 60 mL of MeOH. This solution was heated to 54 C and mixed by a magnetic spin bar for 1 hour. After mixing and heating the solution was poured into a separatory funnel so the glycerin by-product of the reaction could settle and be drained off later (Fig 4.2.1).

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Figure 4.2.1: Fuel and Glycerin[2]

(Photo bears resemblance to actual separation during experiment. No photo was taken)

Once the glycerin was drained the fuel was “washed”. This process could happen two different ways. The first was by pouring water into the seperatory funnel with the fuel, and shaking the apparatus. The system was allowed to settle. The water, along with heavier particles left in the fuel, was then drained off. The second method involved dripping water slowly into the funnel and seemed to require less time then the first method. This yielded roughly 350 mL of useable fuel.

Figure 4.2.2: From Grease to Gas (left to right: Raw oil, Filtered Grease, Washing, Final Product)

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4.2.2 Testing Phase After developing the fuel three important tests were run on the sample. Since established

methods were followed for generating the fuel, as long as it burned, it was fairly certain that the characteristics would be similar to published data. A paper towel was soaked with the fuel and lit it on fire. This was then compared to the burn time of a normal paper towel. As long as the soaked towel burned longer, the fuel could be assumed to work. Second a freezing point needed to be established. The fuel sample was put into a standard home freezer. The fuel froze completely. As the sample thawed its temperature was taken. The freezing point was found to be approximately -2 C, slightly less than that for water. Finally the bio-fuel’s density must be determined to make sure it could flow through a standard diesel engine.

A Brookfield viscometer was used to find dynamic viscosity. This involved rotating a spindle in the fluid, measuring the resistance found and multiplying it by a set number based on spindle and speed. The test was run 6 times to find an average value of 18.9 centipoise or 18.9*10-3 Pa*s (Appendix A). The main obstacle in using the bio-fuel is the high freezing point. The car would become useless from approx 4 C down due to increase in viscosity. 4.2.3 Final Design and other Considerations Three methods were devised to deal with the freezing point problem. The first, easiest, and chosen method is splicing the fuel. In this case straight bio-fuel will not be used to run the engine. Rather a mix of 80% bio-fuel with 20% diesel will power the car. This mixture thins the thicker bio-fuel (Appendix B), but more importantly lowers the freezing point to closer to diesels at -9 C. Future testing should include emissions tests on the 80/20 mixture, to see how much of the bio-fuel’s better characteristics are lost, and compare this to national averages. Two other designs for the fuel system included placing a small battery powered turbine in the tank. By agitating the fuel, it could not freeze. This idea was passed over, because the turbine would have to be running constantly during cold temperatures. The second design called for heating elements in the tank and over the fuel line. Many companies already manufacture heating elements for diesel engines which could thaw frozen fuel in the tank while the car runs on battery power. The real challenge lies in heating the fuel lines and engine. It was thought that heat could be drawn from the battery housing to warm the line from tank to the engine. Finally excess heat from the electrical motor could be used to thaw frozen fuel in the diesel engine. This idea was passed over for complexity and time constraints. 4.3 Motor Placement – Transmission – Switching

In the setup of the vehicle, the project was fortunate enough to have some minimal foundations for construction from years past. An eight inch coil DC electric motor had been used for the Villanova SolarCat in previous vehicles. The university has two of these motors. The other motor is currently used in the Mule. The Mule was a conversion project from a diesel engine to a completely electric driven system. The vehicle can has been used in carrying loads of upwards of 1500 lbs without the vehicle weight. The weight that was calculated for the vehicle after the design modifications was around 2620 lbs. The motor’s output power was 37 hp and reaches 4650 RPMs. Because of the nature of the electric motor producing all of its torque at initial velocity, the motor should have no problem moving the vehicle through the Triumph transmission.

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Choosing the engine was not a simple task. The engine obviously had to be compact, but had to achieve the RPMs of a standard automobile grade engine. This ruled out using something like a Bobcat engine or something from a tractor. The engine also had to be durable and simple to use which ruled out a lot of newer engines. Ideally, an engine with less electrical components was desired so that a specialist wasn’t needed to handle the engine. After a significant amount of research, it was discovered that Volkswagen, in the early eighties, produced a Rabbit in two different engine types. It was a transversely mounted front wheel drive engine. They made both an unleaded model and a diesel model and used the same transmission for both. With this information, data was compared to reveal that the gear ratios between the Triumph TR-7 and that early eighties Volkswagen Rabbit were very similar. Consequently, efforts were dedicated completely to find an engine along these lines. The Rabbit engine that was finally found and acquired could reach 68 hp at 2200 RPMs. The weight of the Rabbit in 1981 was just over 2200 lbs. This was a blessing that the vehicle weights were so close because a lot of the calculation work was already completely for the design of the project. The next step was creating a coupling system to combine the two drives. The Volkswagen transmission was an ideal body to use for such a task. Being that the engine was designed to be transversely mounted and drive the front wheels; the differential is set up so that if manipulated properly, it could be used as an input instead of an output. Inside the transmission, there are three shafts: an engine shaft, an output shaft and a differential shaft. The bellhousing of the transmission mounts directly to the engine. From the engine, the engine shaft runs the length of the transmission casing to a support at the opposite end of the transmission. The output shaft runs parallel to the engine shaft to a similar support at the end of the transmission. Both of these shafts were entirely covered in gears that were not necessary if the Volkswagen transmission were to be used as the coupling mechanism. Consequently, all of these gears were removed. The next step was deciding what shafts were going to be input shafts and which shaft was going to drive the Triumph transmission. The major design question that was faced was if the shafts could withstand all the new torques and RPMs. Again most of the calculation work was taken into account because the VW transmission was already taken into account.

Since the bellhousing mounted directly to the engine, it made sense to use the path of least resistance and keep that consistent. While the differential was the perfect place to mount the DC motor, being that it was the only other place for an input, there wasn’t enough clearance to directly couple the shafts. Instead, something else would have to be set up to provide connection in the offset like a chain drive, meshing gears, or maybe a tooth belt.

Deciding how and where to mount the Triumph transmission required a lot of thought. The clutch on the Rabbit engine is internally activated. A bar runs up the inside of the engine shaft and when pressed applies force on the spring loaded clutch and releases it. This made it impossible to couple the Triumph transmission to the engine shaft; therefore, the output shaft was a logical alternative. Refer to Appendix C where a total model of the coupled systems is shown.

Because of the size and shape of the couple, the output shaft would need to be cut and the couple would need to be applied inside the Rabbit casing. Refer to Appendix D. Here is a model of where the couple is located. There is support for the shafts provided at each end of the Volkswagen housing and by using a flexible couple designed for the appropriate load, the drive system can input into the Triumph transmission.

The next step was mounting the output face of the Volkswagen transmission to the input face of the Triumph transmission. Since the faces looked nothing alike, plates were designed to

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match up to the bolt pattern of each face. The bolt holes were laid out across the plates so that they could be fastened together. Refer to Appendix E. This 3D model is of the adapter plates. It can be seen how the transmission lines up directly to the output shaft.

Finally, a system to prevent back-drive into the opposing drive system needed to be designed. The drive train requires that while one system drives, the other motor has to be bypassed. Knowing this, the idea of the overrunning clutch came to mind. The overrunning clutch works exactly like the freewheel of a bicycle. When a bicycle is going down hill, the velocity is greater than that of the cyclist so the freewheel releases and the pedals remain steady while the bike goes faster. When the rider faces an incline, the freewheel engages and the pedals control maximum velocity of the bicycle. Similarly, by placing an overrunning clutch in each of the two drives, then the system with the highest RPMs will govern the speed of the vehicle without facing friction or back-drive from the opposing system. Refer to Appendices F and G. This is a representation of how the overrunning clutches work by locking in one direction and releasing in the other. In Appendix H, the locations of each of the clutches are shown. In designing the material, size, shape and number of teeth for both the gears and the clutches, a finite element analysis was done. This is shown in Appendix I.

The major design issues left to be conquered are the mounting system for the engine and the motor and the shifting mechanism for the transmission. The engine mounts haven’t been to be designed because there is still a range of locations as to where the engine and motor could rest with regards to the motor mount bolts. The design idea is pretty simple though. It will be a bridge system that is supported by the bolts on the vehicle frame. Motor mounts will be fashioned to adapt the diesel to the bridge and the engine will be supported completely. The motor will sit directly next to the engine and feed into the differential of the engine as stated earlier. The mounts for the motor are located on the outer cylinder of the body and should be able to bolt directly to the frame system. Because the torques and weights of each of these items is known, a finite element analysis will be done to model the structural integrity of the frame.

The shifter will require both electrical and mechanical design. The idea behind the drive train of the vehicle is that it will not require a direct switch because the overrunning clutches force the system to rely on which ever drive is putting out more torque at a higher RPM. Since both systems feed into the Triumph transmission, but the clutch is located internally on the engine, a clutching mechanism is need for the electrical motor. If the shifter of the vehicle can inhibit the motor, then that will act as a clutch for the electrical drive system. Then the system will act as follows:

• Driver places vehicle into gear • Driver then turns the switch of the potbox on • Vehicle speed increases • Driver presses and holds inhibitor button on shifter where the motor cuts out

momentarily • Driver then shifts and speed proceeds to increase • Vehicle reaches 35 mph • Driver revs diesel engine to speed wherein that system overtakes as primary

driving force • Vehicle shifts like a standard automobile with a clutch pedal while running on

biodiesel system as speed increases.

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4.4 Battery Mounts and Arrangement 4.4.1 Preliminary Designs A major component for the electrical design involved with this project entailed determining how to adequately mount and layout the batteries. The layout for the batteries was the first issue addressed and was revised several times. Initially, it was decided that ten batteries would be necessary for providing electric power to the vehicle. Keeping this in mind, the design team had to first assess the amount of space available in the trunk (Figure 4.4.1) where the batteries and contactor for the electrical circuit were to be situated. Two approaches were taken for utilizing the space available. The first approach called for placing two batteries in section #1 of the trunk, four batteries in section #2 of the trunk, and the contactor in section #3 of the trunk. The remaining four batteries would then be mounted inside the cabin of the vehicle (See Appendix J for schematic of this layout). Based on the dimensions of each section of the trunk, the batteries would have adequate space in their respective sections of the trunk (See Appendix L for preliminary design area calculations). The second design scenario involved building a mounting system in which the batteries could be stacked on top of each other, which would allow the team to eliminate mounting batteries in the cabin of the vehicle. In order to evaluate whether or not this would be feasible geometrically, the volumes for ten batteries as well as the volumes of

Figure 4.4.1: Available Space in Trunk of Vehicle sections #1 and #2 of the trunk had to be calculated (See Appendix M). It was determined the trunk would provide ample enough space if this choice was followed. Now that two systems had been conceived, the second phase of the design was to be initiated, which entailed determining

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what type of material was desired for constructing the battery mounts. Ultimately, it was determined that eight batteries, as opposed to ten, would provide ample power for the vehicle, so neither of these two arrangements was used. Upon initiating preliminary research towards determining a material that would provide adequate electrical insulation and strength, it became evident that cost would be a major issue in this area of the design. Regardless of cost constraint, costly ideas provided a large amount of direction towards how the final design was accomplished. First, prefabricated trunk mount battery kits were explored [3]. Unfortunately, it would cost the design team approximately six hundred dollars, which is not within the budget. Some additional battery racks were researched [4], and it was noticed that these manufacturers all constructed their racks out of the same material, .25 inch thick polypropylene. At this point, it was considered that the design team should purchase polypropylene sheets, and build the mounts from scratch. Unfortunately, though, at this time a wholesaler who could meet this need could not be located, so this idea was abandoned for some time. As research continued, the material considered became silicone rubber. Silicone rubber was desired due to its excellent electrical insulating properties, durability, ease of fabrication, and its good thermal conductivity. [5] The design located a company in Philadelphia name Stockwell Elastomeric Inc. [6], who provides extruded sheets of silicone rubber molding. At this point, once again, spacing requirements were determined for the battery configuration if silicone rubber with a thickness of .5 inches was used. It was determined that the space available would be adequate if the battery mounts were constructed out of silicone rubber sheeting. The amount of material necessary to insulate all four sides and the bottom of the batteries was determined at this point as well (See Appendix M). This information was helpful when getting an estimate on the cost of implementing this idea. Once again, after consulting with Brian Shipley, the Manager of Customer Service at Stockwell, it was decided that this design, although apparently ideal, was not cost effective. At this point, the design team returned to the idea of trying to find polypropylene sheet molding for constructing the battery housings. 4.4.2 Final Design Ultimately, it was decided that eight batteries would provide adequate electrical power to the vehicle, which meant another revision in the battery layout. This time, all eight batteries are placed in the trunk, with two in section #1, four in section #2, two in section #3, and the contactor in the cabin (See Appendix K or Figure 4.4.2).

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Figure 4.4.2: Battery placements Now that the final geometry was chosen, the final decision of the design of battery housings had to be determined. Where research failed previously, it succeeded later. A wholesaler named Industrial Plastic Supply [7,8] was located. The design team then purchased 16 square feet of extruded polypropylene sheets, at a thickness of 1/8 inch, to be used for insulating the batteries. This method only cost about fifty dollars as opposed to about six hundred dollars for the preliminary designs. Since the polypropylene is relatively thin, ¼ inch thick plywood was used to provide additional support (See Figures 4.4.3 and 4.4.4).

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Figure 4.4.3: Battery Housing The battery housings were constructed by fastening four sectioned pieces of plywood together using two zinc plated two inch corner braces at each corner. The inner lining is composed of four sectioned pieces of the polypropylene sheeting. In order to make the sections that would provide a tight fit for the batteries, the lengths and widths for the sectioned pieces had to first by determined by calculating the ideal dimensions based on the battery dimensions plus the thickness of the two materials (See Appendix L for schematic and Appendix N for calculations). Utilizing these dimensions, it was next determined if the trunk would provide enough space for the eight batteries plus the housings (See Appendix N). After constructing the eight battery housings, they were secured in the base of the trunk by putting two 3/8 inch (thread) by 2 inch (length) carriage bolts through the base of the trunk, which rested snugly against the battery housings. At this point, the wiring for the electrical circuit could now be completed.

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Figure 4.4.4: Finished Housing 4.5 Electrical Systems 4.5.1 Electrical Subsystem Design Overview

Since the primary objective of the hybrid car’s electrical subsystem is to safely propel the vehicle from a standstill up to a velocity of 35 mph, both the electrical motor, motor controller, and its associated battery supply would have to be adequately chosen to meet this need. However, since the project was already provided with the Advanced 8” DC motor, Albright SW200 contactor, and Curtis 1221c motor controller, a decision was made to base the electrical subsystem off these components.

Thus, the essential electrical design would consist of the Advanced 4001 series 8” DC electrical motor (Figure 4.5.1), which produces a peak of 37 H.P. at 4650 RPM, supplying power directly to the Triumph’s drive train, which would in turn drive the rear wheels and propel the vehicle.

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Figure 4.5.1: Advanced 4001 Series 8” DC Motor Cutaway Illustration

The Curtis 1221c DC motor speed controller (Figure 4.5.2) would serve as the interface

between the battery bank and the DC motor itself, with inputs for the positive and negative battery voltages as well as positive and negative voltage outputs to the DC motor. Therefore, the 1221c would effectively function as a speed regulator with a simple 5KΩ lever-operated potentiometer serving as the throttle input to the controller (with ~0Ω as the zero power point, and ~5KΩ the full power point), as specified by the controller’s manual [12].

Figure 4.5.2: Curtis 1221c DC Motor Controller

Finally, the Albright CT-SW200 DC contactor (Figure 4.5.3) would serve as a specialized relay between the battery bank and DC controller, in order to ensure that the high current (200+ amps [13]) demands of the electrical motor would be sufficiently met. This contactor would also serve as a sort of fuse, in that it would break the circuit in case of a short circuit event, with a typical fault current of 1500A [14].

Figure 4.5.3: Albright SW200a Contactor

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Due to the fact that most of the critical components for the design were already provided

to the team, four essential tasks remained for finalizing the design: the calculation of the voltage necessary for proper horsepower delivery from the DC motor, the calculation and choice of batteries for powering the DC motor, the calculation of the proper wire size necessary for the battery cables, and the design of the power switch system for powering off the electrical subsystem when the vehicle is running solely on diesel power. 4.5.2 Electrical Subsystem Design

The calculation of the DC voltage necessary for powering the 8” Advanced motor was the first task in preparing the preliminary electrical subsystem design. The choice of voltage was constrained by two important factors – the maximum operating voltage of the DC motor and the maximum input/output voltage of the DC controller. After looking through the specification sheets for the motor and controller, it was found that both the motor’s maximum operating voltage and the input/output voltage of the DC controller was 120v. Since the motor’s specification also stated that it produced its maximum power (29 horsepower) at this voltage, it was initially decided that it would be prudent to use a 120v supply because it would allow the electric motor to produce its maximum power, something which would also allow the hybrid vehicle to achieve the best possible straight-line acceleration.

With the system’s operating voltage chosen, the next task was to find adequate batteries to power the vehicle. Initially, the focus was on adapting an off-the-shelf, nickel-metal hydride hybrid battery pack for the vehicle, such as the one found in the current generation Toyota Prius. It had been hoped to utilize these NiMH batteries because of their superior (when compared to standard lead-acid batteries) energy density ratings [15], but several technical issues emerged after researching the feasibility of adapting such a battery pack for the electrical subsystem.

The first, and probably most significant, issue was that these battery packs were designed

to operate specifically with the motor controller of the original vehicle. This would pose a significant problem, because the battery pack would somehow have to be adapted in order to work with the electronics in the Curtis 1221c motor controller. The next issue encountered was that every single NiMH battery pack that was found had a rated voltage substantially higher (most packs, including that of the Prius, supply more than 250v) than that of the voltage that was planned on being utilized [16]. Thus, these two issues, along with the fact that it was extremely difficult to locate a supplier selling new, non-used NiMH battery packs led the team to eventually abandon the idea of using an off-the-shelf NiMH battery pack for the vehicle’s battery supply.

After determining that the use of NiMH batteries would be entirely unfeasible due to the aforementioned reasons, research was done on utilizing common lead-acid batteries for the hybrid’s battery pack. The first initiative was to investigate the different types of lead-acid batteries and determine which type would fit the design constraints the best. Due to the large current draw (200+ amps) of the DC motor, it was ascertained that the type of lead-acid battery chosen would have to deal well with high-discharge rates and discharge conditions (i.e. consistently draining the batteries of more than 80% of their stored charge). Therefore, after the

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research was completed, it was discovered that the use of deep-cycle sealed lead-acid batteries would fit well with the needs of the design, due to their ability to be substantially discharged and still provide a consistent level of current output [17]. After looking through the average types of inexpensive deep-cycle batteries, it was found that a relatively lightweight (less than 40 lbs) marine battery would provide an energy rating of approximately 30 Ampere-hours, for a total battery pack energy capacity of 3.6 Kilowatt-hours.

Figure 4.5.4: MK 8A22NF Deep-Cycle Lead-Acid Battery

Having ascertained that the deep-cycle lead-acid batteries would fit the design well,

several electrical-only range and acceleration estimations were made in order to see if such a battery supply would be adequate for the needs of the electrical subsystem. These estimations were done by using a suite of Excel spreadsheets written by Prof. Koffke which takes into account factors such as the vehicle’s frontal area, drag resistance, rolling resistance, electrical motor power, weight, and total battery energy capacity as can be seen in Appendix R. These estimations confirmed the theory that the 3.6 KW-hour battery pack would be adequate for the needs of the design, because they showed that these batteries would allow the vehicle to have a range of approximately 40 miles if run at a velocity of 35 mph on battery power alone as well as having an instantaneous acceleration rate of more than 14 feet per second2.

With the feasibility of using lead-acid batteries fully evaluated, it came time to find a manufacturer and supplier able to provide the correct type (i.e. relatively lightweight deep-cycle) of batteries for the design. It was quickly determined that MK Battery, a well-known battery manufacturer based out of Anaheim, California would be able to supply the necessary 12v batteries. However, a new issue now emerged regarding the choice of lightweight, sub-30lb batteries versus heavier, ~40lb batteries. Since MK Battery makes 25lb, 32 Ampere-hour and 39lb, 55 Ampere-hour batteries, it is clear that the heavier battery offers an approximately 10% higher energy density rating (1.41 Ah/lb versus 1.28 Ah/lb) [18]. Therefore, a choice was made to utilize the heavier, more energy-dense MK 8A22NF batteries (Figure 4.5.4). The selection of the heavier deep-cycle batteries created a new issue to consider, one of weight and price. Since these MK 8A22NF batteries each weigh 39lbs, the usage of ten of them in series to achieve the chosen supply voltage of 120v would create a total battery pack weight of 390lbs, an increase of 140lbs over the initially projected battery pack weight (based on the lighter 8AU1H batteries). Consequently, because each heavyweight battery costs at least 30% more than its lightweight counterpart [19], the project’s budget would not allow for the purchase

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of a sufficient amount of batteries to allow ten main batteries and a few backup batteries in the case of battery failure. Thus, a choice had to be made between dropping the usage of the heavier MK batteries for the lighter 8AU1H series, or dropping the supply voltage to 96v and using the heavier batteries. After doing a quick series of calculations, it was noted that the usage of the heavier batteries in a 96v configuration would still yield a 5.28 KW-hour energy density rating, compared to the 3.84 KW-hour energy density rating of the 120v/8AU1H battery configuration, a difference of 33%. Thus, the drawbacks of using the heavier batteries in a 96v configuration would be a lower power output of 32 horsepower from the DC motor [13] and a heavier battery pack weight of 312lbs (as compared to 250lbs for the 120v/8AU1H configuration). In order to compare the range and acceleration of the two battery pack configurations, the electrical vehicle parameter estimation spreadsheets were once again utilized as seen in Appendix P. It was found that the 96v/8A22NF configuration allowed the hybrid vehicle to achieve a 25% greater electrical-only range than the 120v/8AU1H configuration when driven at 35 mph. Thus, it became a relatively easy choice to make in the regard of choosing batteries and their voltage configuration – the substantial range boost provided by the 96v/8A22NF setup clearly offsets its minutely adverse effect on acceleration (primarily due to the added weight of the more energy-dense batteries). Therefore, the choice was finally made to utilize a 96v battery system using the MK 8A22NF deep-cycle 55 Ampere-hour batteries.

The design and layout of the electrical subsystem schematic was based on the design constraint of using a 96v battery supply to power the Advanced 8” DC electrical motor. This would require the implementation of eight 12v sealed-lead acid batteries in series to achieve this desired voltage. Likewise, the Albright SW200a contactor, Curtis 1221c controller, and Advanced 8” DC motor would also have to be modeled and included in the schematic. To keep the main battery-pack voltage completely isolated from the control circuit (i.e. potentiometer), it was decided to utilize the vehicle’s auxiliary 12v battery for the purpose of throttle power and switching. Therefore, in order to keep the switching system between the DC motor and diesel engine relatively simple and easy to implement, a simple SPDT (single pull, double-throw) switch would be placed between the positive auxiliary voltage terminal and potentiometer, so that the throttle input for the DC motor could be instantly switched on and off. Likewise, a polarity protection diode would also be placed between the control fuse and SPDT switch, so that the polarity of the voltage input for the potentiometer could not be reversed and thus prevent any potentially disastrous throttle behavior. In order to ensure absolute electrical safety, especially in the case of a short-circuit event, two fast-acting Ferraz Shawmut 400A/250v [20] fuses would also be added – one between the positive battery output terminal and the contactor, and one between the potentiometer and auxiliary 12v battery. These fuses ensure that both the DC motor’s throttle and power supply would be disabled in the case of a short-circuit. With these design and safety decisions made, the final schematic was created to serve as a reference for the overall electrical design and assembly in Appendix S. With the overall design and electrical subsystem schematic completed, the last remaining design task was to calculate the size of the wiring required for the battery cables. Since the size of the wire is dependent solely on the maximum amperage used (overstated to be 200 amps, since the maximum amperage draw of the Advanced DC motor at 35 mph is 170 amps [13]), the voltage utilized (96v), the estimated length of the wire (50ft, based on the wheelbase of the

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vehicle), and the allowable percent voltage drop (1%, in order to ensure as small a voltage fluctuation as possible), these parameters were used to calculate the voltage drop index as seen in Appendix T. Thus, the calculations showed that with a voltage drop index of 58, battery wiring of size #2/0 would be used. 4.5.3 Testing and Conclusions With all of the critical electrical components (i.e. potentiometer, batteries, fuses, cables, and miscellaneous parts) ordered and received, it came time to perform the testing of the electrical subsystem and its components. To begin, the team tested each individual battery by charging it at 14v until it was fully charged at 12v, which was measured with a digital voltmeter. Next, these charged batteries were allowed to sit unloaded for 24 hrs to determine if any voltage leakage or fluctuation occurred. When it was determined that each battery was non-defective and fully functioning, the eight batteries were connected in series and the series voltage was checked with a digital voltmeter. With this step verified and completed, the next task was to connect the battery pack and potentiometer to the Curtis 1221c DC controller and verify with a digital voltmeter that the output voltage from the controller was being regulated correctly with regards to the position of the potentiometer. Once this was checked and confirmed, the final testing and verification step was to connect the controller and battery pack to the Advanced DC motor and verify that the motor would operate freely without a load. With this final step demonstrated and checked, the testing phase of the project was completed. Unfortunately, no further testing, including actual in-vehicle performance and application confirmation, could be completed due to the time constraints placed on the team by the extended design phase and stumbling blocks encountered.

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5. COST ANALYSIS Table 1: Cost Analysis

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The chart on the previous is a list of the total cost of the project. Each section is divided up individually with their subtotal. The project started off with $3,000 in the budget, as well as about $1,500 from selling the old Solar Cat car left in the garage. As can be seen, the project remained under budget with a little left over. This left over a mount could be used to fix up any loose ends that need to be finished on the car, such as the hatchback trunk and engine insertion.

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6. CONCLUDING REMARKS

The original intent of the design project was to design and build a functioning hybrid vehicle. Unfortunately this lofty goal was not achieved. From an electrical perspective, the car could be wired within 2 weeks. The design and purchase of the electrical components was completed in a timely manner. Similarly the housing for the batteries is complete and each battery can be mounted to its proper place. Neither of this has occurred yet, because the exact positioning of the electric motor is still in question. The mounting system for the electrical diesel engine in the front of the car has not been fully completed. This is due to the issues in modifying the transmission. It took more time than originally planned to open the transmission and even more to map its odd bolt hole configuration for a new adapter plate. Progress on modifying the exterior of the car is proceeding, once again slightly behind schedule, but can be completed before the end of the semester. Finally using bio-fuel as gasoline is well within the realm of plausibility, but it is being used as a spliced mixture with standard diesel. Future incarnations of this project may look into optimizing the heat transfer elements in the gasoline tank and along the fuel lines, or even possibly altering the bio-fuel itself to achieve better emission qualities. Looking at the project and team as objectively as possible, there are positives and negatives. On a positive note the team has faced this project with the utmost enthusiasm and has consistently imagined unique solutions to many challenges. Also the team has taken great strides to ensure work on the Hybrid Vehicle will succeed them by re-establishing an old club with active underclassmen. Glancing at the negative side, this team seemed to have overreached their grasp. Goals were set in time constraints that may not have been truly feasible. The main goal of the project may have been lost among all the interesting side projects that developed. Perhaps the point where this team truly shines however is in its cross discipline nature. Comprised of 4 Mechanical Engineers and 2 Electrical Engineers this project has definitely provided a broader idea of engineers working together. During many sessions each discipline would have to explain, in less specified terms, their progress and goals to the others. While not technically members of the design team, the club based around the project also has an inherent interdisciplinary nature. The broad reach of the project not only included Mechanical and Electrical Engineers, but has relied on Chemical Engineers with interest and aid from the Chemistry Department. Chemical reactions were performed (within the utmost safety measures) immediately next to a dismantled transmission, which was situated across from a stack of electrical batteries. Watching the full team and club work together was often quite an experience. If any lessons should be taken from this experience it must include a section on time management and organization. Conflicting schedules and curriculums would often delay progress by unnecessary amounts of time. These lessons could not be complete though, without the knowledge that even though the advanced concepts may be different for each discipline, there are shared traits and interests among all engineers. With a little effort and ingenuity these interests can be examined and discovered in a multifaceted way leading to deeper insights for all involved.

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7. REFERENCES

1. National Bio-Diesel Board, 2007, http://www.biodiesel.org, (March 18th 2007) 2. Journey to Forever, 2006, http://journeytoforever.org/, Keith Addison, (September 2006). 3. PDS Electronics Inc. http://www.dxengineering.com/ (October 13, 2006). 4. Electro Automotive, 2007, http://electroauto.com/ (October 14, 2006). 5. Alibaba.com, 2007. http://alibaba.com/ (November 27, 2006). 6. Stockwell Elastomerics, Inc., 2007. “Delivering Innovation in High Performance

Elastomers.” http://www.stockwell.com/ (December 29, 2006). 7. Industrial Plastic Supplier, Inc., 2007.

http://www.indplastic.com/index.cfm?id=266632&fuseaction=browse&pageid=1 (January 18, 2007).

8. Acrilex, Inc., 2007. “The Total Picture.” http://www.Acrilex.com/ (January 18, 2007). 9. Atlas Gear Company, 2004, http://www.atlasgear.com 10. R + W Coupling Technology, http://www.rw-couplings.com/start_bk.html 11. SAE International, 2007 http://www.sae.org/technical/papers/781039 12. “Curtis PMC 1209b/1221b/1221c/1231c Manual,” Curtis Instruments Inc., p.20-30,

Livermore, California (1999) 13. “Electric Vehicle Applications Guide,” Advanced D.C. Motors Inc., p.2, East Syracuse,

New York (1992) 14. “SW200 Series of D.C. Contactors,” Albright International LTD, p.5, Surrey, England

(1993) 15. “Energy Density,” Transtronics Inc., http://xtronics.com/reference/energy_density.htm,

(2006) 16. “Toyota Prius Battery Pack Information,” The Clean Green Car Company,

http://www.cleangreencar.co.nz/page/prius-battery-pack, (2005) 17. “Deep Cycle Battery FAQ,” Northern Arizona Wind & Sun Inc.,

http://www.windsun.com/Batteries/Battery_FAQ.htm, (2006) 18. “MK Battery AGM Specifications,” MK Battery,

http://www.mkbattery.com/images/lagm.pdf, (2001) 19. “RV and Marine Batteries,” Batterystuff LLC, http://batterystuff.com/batteries/rv-

marine/, (2007) 20. “A2K and A6K Fuses,” Ferraz Shawmut Inc.,

http://www.ferrazshawmut.com/products/pdf_107/A2K&A6K.pdf, (2005)

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Appendix A Table 2: Brookfield Viscometer Test Results Brookfield Viscometer Test

Speed Multiplier ReadingCentipoise Value Pa*s

Spindle 3 3 - - - 6 - - - 12 - - - 30 10 2 20 0.02 60 5 3.5 17.5 0.0175 Spindle 1 6 10 2.5 25 0.025 12 5 3.8 19 0.019 30 2 7.5 15 0.015 60 1 17 17 0.017 Average 18.92 0.0189

Appendix B Calculation of Diesel Dynamic Viscosity

ρ 950kg

m3⋅:= Diesel Density

Diesel Kinematic Viscosityν 6 10 6−

⋅m2

s⋅:=

τ ρ ν⋅:= Dynamic Viscosity = Denisty * Kinematic Viscosity

τ Pa s⋅= Diesel Dynamic Viscosity

τ 5.7 10 3−

× Pa s⋅=

30

Appendix C- 3D Model of Assembled Drivetrain

31

Appendix D – 3D Model Showing Flexible Coupling and Location Appendix E – Dimensioned 3D Model of Adapter Plates

32

Appendix F – Free Body Diagram of Overrunning/Sprag Clutches Appendix G – 2D Drawing of Sprag/Overrunning Clutches

33

Appendix H – 3D Model Highlighting Location of Overrunning Clutches

34

Appendix I – Finite Element Analysis of Stress on Gears

35

Appendix J: Top View of Trunk Area Preliminary - Preliminary design for battery layout, involves 6 batteries in trunk and 4 in cab, with

contactor in trunk on right side - Note all dimensions scaled down by ½ (inches)

36

Appendix K: Top View of Trunk Area Final -Note all dimensions scaled down by ½ (inches)

37

Appendix L: Top View of Battery Housing Design - all dimensions in inches - dimensions include length and width of battery, polypropylene lining, and plywood

sections

38

Appendix M: Trunk Spacing

39

40

Appendix N: Trunk Spacing Continued

41

42

Appendix 0: Tour Del Sol Categories: Reliability:

Vehicles drive from town to town on each day of the competition. Vehicles are timed on most legs of the route; however, the point of the rally is not speed. Vehicles will be judged on whether they can complete each leg within a specific window of time. To account for traffic and other variables a pace car will lead the Rally and is used to set the maximum and minimum times.

Route:

All rally vehicles must drive the official Tour route, and there will be spot checks to ensure that all vehicles comply.

Long Acceleration:

The acceleration event measures the time a vehicle takes to complete a fixed distance from a standing start. The raw score will be the time a vehicle takes to complete a 1/8-mile (660 feet) straight acceleration run.

Handling:

The Handling/Autocross test measures the handling ability of the vehicles. A paved course with tight turns will be set up using traffic cones. The Organizers will measure the time a vehicle takes to complete the course.

Range & Reliability:

The goal of the Range and Reliability event is to demonstrate the driving range capabilities of the vehicles at normal road speeds in highway and secondary road driving conditions without recharging or refueling the on-board energy storage system. The Range event will take place on one of the days of the Tour. The total range of a vehicle will include the distance traveled during the rally plus any additional range laps it can complete before the end of the day. The start time for laps and the start time for the final lap will be noted in the Drivers Manual and will provide enough time for a typical vehicle to drive 250 to 300 miles.

Vehicle Efficiency:

The Vehicle Efficiency event is based upon the total amount of energy a vehicle uses over several days of the competition. The raw score (MPGe) will be based upon the amount of electrical or fuel energy and mileage used over specific days of the rally as described in the final itinerary (one of these days will ideally include the Range event).

Gas Emissions:

This event evaluates the amount of carbon dioxide (CO2) a vehicle produces during several days of the competition. The raw score will be based upon the amount of energy (electrical and fuel) a vehicle uses and the total carbon dioxide (CO2) emissions it takes to produce, distribute, and consume the energy.

43

Hill Climb: This event measures the ability of a vehicle to drive an incline. It is a discretionary event, and will only be held if an appropriate location is available. The length and slope of the course will vary depending on the location and will be described in the final itinerary. The time a vehicle takes to complete the hill climb will be compared with the other vehicles,

44

Appendix P: Acceleration Charts and Graphs

Estimated Maximum AccelerationTR-7 Hybrid (purely electric power)

0.0000

5.0000

10.0000

15.0000

20.0000

25.0000

0 10 20 30 40 50 60 7Speed (mph)

Tim

e (s

ec)

0

Figure 1.1

Acceleration Vs. Time

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

0.0000 5.0000 10.0000 15.0000 20.0000 25.0000

Time (sec)

Acc

eler

atio

n (ft

/sec

)

Figure 1.1

45

Table 3: Data for Acceleration Graphs

Wheel Motor Wheel Traction Time

to Elapsed v V Speed Speed Torque Force Drr A speed Time

MPH ft/sec RPM RPM ft·lbs lbs lbs ft/sec^2 sec Sec 0 0.00 0.0 0 990.61 1189 68.6 13.88 5 7.33 84.1 905 990.61 1189 71.2 13.84 0.5284 0.5284 10 14.67 168.1 1810 990.61 1189 73.8 13.80 0.5298 1.0582 15 22.00 252.2 2716 990.61 1189 76.4 13.74 0.5315 1.5898 20 29.33 336.3 2172 594.366 713.5 79.0 7.79 0.5336 2.1234 25 36.67 420.3 2716 594.366 713.5 81.6 7.72 0.9413 3.0646 30 44.00 504.4 2128 388.102 465.9 84.2 4.58 0.9498 4.0144 35 51.33 588.5 2482 388.102 465.9 86.8 4.49 1.6025 5.6169 40 58.67 672.5 2837 388.102 465.9 89.4 4.39 1.6334 7.2503 45 66.00 756.6 2044 248.602 298.4 92.0 2.22 1.6687 8.9189 50 73.33 840.7 2272 248.602 298.4 94.6 2.11 3.3071 12.226155 80.67 924.7 2499 248.602 298.4 97.2 1.99 3.4825 15.708560 88.00 1008.8 2726 248.602 298.4 99.8 1.86 3.6930 19.401565 95.33 1092.9 2953 248.602 298.4 102.4 1.72 3.9482 23.3497

Appendix Q: Electrical Range vs. Speed

Power Required vs SpeedTR7 Hybrid (96v 55Ah)

0

5

10

15

20

25

30

35

40

45

0 20 40 60 80Speed (MPH)

RA

NG

E (m

i)

Battery only RangeHorsepowerKilowatts

Figure 1.1

.

46

Table 4: 96V System Using 8x 55Ah Batteries

V V Drr Dwr Dt P P P Time Range MPH ft/sec lbs lbs lbs ftlbs/s hp kW hr Mi

0 0 66.52 0 66.53 0 0 0 5 7.33 69.04 0.28 69.33 508.4 0.924 0.689 7.659 38.29 10 14.67 71.56 1.12 72.70 1066 1.939 1.445 3.652 36.52 15 22.00 74.08 2.53 76.63 1686 3.065 2.285 2.310 34.65 20 29.33 76.60 4.51 81.12 2379 4.326 3.226 1.636 32.73 25 36.66 79.12 7.04 86.18 3160 5.745 4.284 1.232 30.81 30 44.00 81.64 10.10 91.80 4039 7.344 5.476 0.964 28.92 35 51.33 84.16 13.81 97.98 5030 9.145 6.819 0.774 27.09 40 58.66 86.68 18.04 104.7 6144 11.17 8.330 0.633 25.35 45 66.00 89.20 22.84 112.0 7395 13.45 10.02 0.526 23.69 50 73.33 91.72 28.19 119.9 8794 15.99 11.92 0.442 22.14 55 80.66 94.24 34.11 128.4 10354 18.83 14.03 0.371 20.68 60 88.00 96.76 40.60 137.4 12088 21.98 16.38 0.322 19.32 65 95.33 99.28 47.65 146.9 14008 25.47 18.99 0.278 18.07

47

Appendix R: 120V System Using 10x 32Ah Batteries

Power Required vs SpeedTR7 Hybrid (120v 32Ah)

0

5

10

15

20

25

30

35

0 20 40 60 80Speed (MPH)

RA

NG

E (m

i)

Battery only RangeHorsepowerKilowatts

48

Appendix S: Electrical Schematic

Figure 1.1

***Correction: This was the initial design with 10 batteries. The final design only has 8 batteries.

49

Appendix T: Wire Sizing Chart

333.58120*%1

35*200~*%*

===V

ftAVoltageVdropFeetAmpsVDI

50

STATEMENT OF INDIVIDUAL CONTRIBUTIONS

C. R. Adcock Interior/Exterior _______________________ C. A. Ayers Electrical Components _______________________ T. J. Grisillo Fuel Systems _______________________ K. M. Heselpoth Battery Placement _______________________ I. A. Kirillov Electrical Components _______________________ K. V. McCauley Transmission _______________________ Switching Mechanism