DESIGN OF FLY WHEEL

by P.B ASHOK K.RAVI KUMAR

Abstract:

Flywheels serve as kinetic energy storage and retrieval devices with the ability to deliver high

output power at high rotational speeds as being one of the emerging energy storage technologies

available today in various stages of development, especially in advanced technological areas, i.e.,

spacecrafts. Today, most of the research efforts are being spent on improving energy storage

capability of flywheels to deliver high power at transfer times, lasting longer than conventional

battery powered technologies.

Mainly, the performance of a flywheel can be attributed to three factors, i.e., material strength,

geometry (cross-section) and rotational speed. While material strength directly determines kinetic

energy level that could be produced safely combined (coupled) with rotor speed, this study solely

focuses on exploring the effects of flywheel geometry on its energy storage/deliver capability per

unit mass, further defined as Specific Energy. Proposed computer aided analysis and optimization

procedure results show that smart design of flywheel geometry could both have a significant effect

on the Specific Energy performance and reduce the operational loads exerted on the shaft/bearings

due to reduced mass at high rotational speeds.

An automotive system using a high speed, moderate mass regulator capable of storing and

apace dissipating massive provides of mechanical energy let alone a transmission custom-made to

allow the graceful unleash of keep mechanical energy from the regulator to the vehicle wheels and a

charging means that for activity mechanical energy to the regulator at comparatively low energy

levels.

Actually, it's the energy that's keep within the type of mechanical energy. It resists modification

within the motion speed, as a results of that the rotation of the shaft becomes steady. sensible qual-

ity flywheels square measure fabricated from metal, as they're lightweight. Aluminium Alloy is ad-

ditionally being employed, because it ends up in high-energy storage. the burden of high-quality

flywheels employed in engines ranges from 13-25 kilo so Very light. This light-weight ends up in

fast engine response.

In this paper we adapt IC engine flywheel and design in CAD software namely CATIA V5 R20.

This has very advanced designing and drafting tools. Modelling of flywheel is done with required

dimensions and aluminium alloy material is applied to the model design.

Contents

Abstract

Chapter 1: Introduction of Flywheel

Introduction1.1 Flywheel orgins

1.2 Comparison among Alternative Forms of Energy Storage

1.3 Theoretical analysis

1.4 Application

1.5 Advantages and disadvantages

1.61 Advantages

1.62 Disadvantages

Chapter 2: Literature survey

2.1 Recent developments

2.2 Theoretical analysis

2.3 Design

1. INTRODUCTION OF FLYWHEEL

1.1 Introduction

A flywheel is a mechanical device with a significant moment of inertia used as a storage

device for rotational energy. Flywheels resist changes in their rotational speed, which helps

steady the rotation of the shaft when a fluctuating torque is exerted on it by its power

source. flywheels have become the subject of extensive research as power storage devices

for uses in vehicles. flywheel energy storage systems are considered to be an attractive

alternative to electrochemical batteries due to higher stored energy density, higher life

term, deterministic state of charge and ecologically clean nature.

Flywheel is basically a rechargeable battery. It is used to absorb electric energy from

a source, store it as kinetic energy of rotation, and then deliver it to a load at the

appropriate time, in the form that meets the load needs. As shown in Fig1, a typical

system consists of a flywheel, a motor/generator, and controlled electronics for

connection to a larger electric power system.

Figure 1.1Basic components of flywheel wheel energy storage system

The input power may differ from the output power in its temporal profile, frequency, or

ther attributes. It is converted by the input electronics into a form appropriate for efficiently

driving a variable-speed motor. The motor spins the flywheel, which stores energy

mechanically, slowing down as it delivers energy to a load. That decrease in mechanical

energy is converted into electrical form by the generator. A challenge facing the motor and

the generator designer is to size the system for the amount of storage (energy) and delivery

rate (power) required and also to minimize losses. The output electronics convert the

variable-frequency output from the generator into the electric power required by the load.

Since the input and output are typically separated in a timely manner, many approaches

combine the motor and generator into a single machine, and place the input and output

electronics into a single module, to reduce weight and cost.

Modern high-speed flywheels differ from their forebears in being lighter and spinning

much faster. Since the energy stored in a flywheel increases only linearly with its moment

of inertia but goes up as the square of its rotational speed, the tradeoff is a good one. But it

do raise two issues: flywheel strength and losses caused due to air friction. To keep from

flying apart, modern flywheels are complex structures based on extremely strong materials

like Aluminium Alloy.

.

1.2 Flywheel Origins

The origins and use of flywheel technology for mechanical energy storage began

several hundred years ago and developed throughout the Industrial Revolution. One of

the first modern dissertations on the theoretical stress limitations of rotational disks is the

work by Dr.A.Stodola, whose first translation to English was made in 1917. Development

of advanced flywheel begins in the 1970s.

1.3 Comparison among Alternative Forms of Energy Storage

Chemical batteries are widely used in many applications currently. But there are a

number of drawbacks of chemical batteries.

1. Narrow operational temperature range. The performance of the chemical battery will

be deteriorated sharply at high or low temperature.

2. Capacity decreases over life. The capacity of the chemical battery cannot be maintained

in a high level all through its life, the capacity will decrease with time goes on.

3. Difficulty in obtaining charge status. It is not so easy to know the degree of the

charge of the chemical battery because the chemical reaction in the battery is very hard to

measure and control.

4. Overcharge and over-discharge. Chemical battery can neither be over-discharged nor

be over-charged, or its life will be shorted sharply.

5. Environmental concerns. Many elements of the chemical battery are poisonous, they

will do harm to the environment and the people.

Obviously, the presence of the shortcomings of the chemical batteries makes them not-

so-appealing to the users nowadays. Instead, flywheel energy storage system become

potential alternative form of energy storage.

Table.1.1 Comparison among two energy storage systems

Lead-acid Flywheel

battery battery

Storage mechanism Chemical Mechanical

Life(years in service) 3-5 >20

Technology Proven Promising

Number of manufacturers ~700 ~10

Annual

Sales(US

~7000 ~2$millions)

Temperature range Limited Less Limited

Environmental concerns Disposal issues Slight

Relative sizeLarger Smallest

(equivalent power/energy)

Price, per kilowatt $50-$100 $400-$800

Table1 shows the comparison among chemical battery and flywheel energy storage

system . Given the state of development of flywheel batteries , it is expected that costs for

flywheel can be lowered with further technical development. On the other hand,

electrochemical batteries already have a tremendous economy of scale that has driven

costs down as far as they are likely to go.

Besides what have been mentioned in table1, there are also some other potential

advantages that flywheel energy storage system has over chemical battery. Refer to:

1. Higher energy storage density. The flywheel battery whose speed exceeds

60000r/min can generate more than 20Whrs/lbm energy . But the energy storage density

of the nickel-hydrogen battery is only 5-6 Whrs/lb.

2. No capacity decreases over life. The life of the flywheel battery depends mainly on

the life of power electronic devices and can reach about 20 years.

3. No overcharge and over-discharge. The performance of the flywheel battery is not

influenced when it is discharged heavily, and the overcharge can be avoided with

assistance of power electronic devices.

4. Since mechanical energy is proportional to the square of the flywheel speed, the

stored energy level indicator is a simple speed measurement. In addition, the charge of

the flywheel battery can be restored in several minutes, but it will take about several

hours for chemical battery to charge.

1.4 Theoretical analysis

Energy is stored in the rotor as kinetic energy, or more specifically, rotational energy:

where

ω is the angular velocity, and

I is the moment of inertia of the mass about the center of rotation.

The moment of inertia for a solid-cylinder is ,

for a thin-walled cylinder is ,

and for a thick-walled cylinder is .

where m denotes mass, and r denotes a radius. More information can be

found at list of moments of inertia

When calculating with SI units, the standards would be for mass,

kilograms; for radius, meters; and for angular velocity, radians per second.

The resulting answer would be in Joules

The amount of energy that can safely be stored in the rotor depends on the

point at which the rotor will warp or shatter.

whereσt is the tensile stress on the rim of the cylinderρ is the density of the cylinder

r is the radius of the cylinder, and1ω is the angular velocity of the cylinder.

Applications

1.51Transportation

In the 1950s flywheel-powered buses, known as gyrobuses, were used in Yverdon,

Switzerland, and there is ongoing research to make flywheel systems that are smaller,

lighter, cheaper, and have a greater capacity. It is hoped that flywheel systems can

replace conventional chemical batteries for mobile applications, such as for electric

vehicles. Proposed flywh

Flywheel power storage systems in current production (2001) have storage capacities

comparable to batteries and faster discharge rates. They are mainly used to provide

load leveling for large battery systems, such as an uninterruptible power supply for

data centers

Flywheel maintenance in general runs about one-half the cost of traditional battery

UPS systems. The only maintenance is a basic annual preventive maintenance routine

and replacing the bearings every three years, which takes about four hours.

1.53 Amusement ride

The Incredible Hulk roller coaster at Universal's Islands of Adventure features a

rapidly accelerating uphill launch as opposed to the typical gravity drop. This is

achieved through powerful traction motors that throw the car up the track. To achieve

the brief very high current required to accelerate a full coaster train to full speed

uphill, the park utilizes several motor generator sets with large flywheels. Without

these stored energy units, the park would have to invest in a new substation and risk

browning-out the local energy grid every time the ride launches.

1.54 Motor sports

The FIA has re-allowed the use of KERS (see kinetic energy recovery system) as part

of its Formula 1 2009 Sporting Regulations. Using a continuously variable

transmission (CVT), energy is recovered from the drive train during braking and

stored in a flywheel. This stored energy is then used during acceleration by altering

the ratio of the CVT. In motor sports applications this energy is used to improve

acceleration rather than reduce carbon dioxide emissions—although the same

technology can be applied to road cars to improve fuel efficiency.

1.55 Flywheel energy storage systems are widely used in space, hybrid vehicles,

military field and power quality. Space station, satellites, aircraft are the main

application field in space. In these fields, flywheel systems function as energy storage

and attitude control. For the applications in hybrid vehicles and military field,

flywheel systems are mostly used to provide pulse power. But for power quality

application, flywheel systems are widely used in USP, to offer functions of

uninterruptible power and voltage control.

Figure 1.2 Applications of Flywheel Energy Storage System

Figure 3 shows an example of NASA on the FESS development. The blue arrows

represent energy storage combined with attitude control, which mostly used in space

stations, satellites, and so on. Red arrow represents pulse power, which are used in

aircrafts, combat vehicles and hybrid electric vehicles. green arrow represents

uninterruptible power & voltage control, which is used in UPS, aircraft launch and utility

peaking. From the figure, we can see that NASA’s near term researches on flywheel are

mostly concentrated on space applications, but the far term researches are turning to

industry applications gradually.

¡¡

1.6 Advantages and disadvantages

1.61 Advantages

Flywheels store energy very efficiently (high turn-around efficiency) and have the

potential for very high specific power(~ 130 W·h/kg, or ~ 500 kJ/kg) compared with

batteries. Flywheels have very high output potential and relatively long life. Flywheels

are relatively unaffected by ambient temperature extremes. The energy efficiency (ratio

of energy out per energy in) of flywheels can be as high as 90%. Typical capacities range

from 3 kWh to 133 kWh. Rapid charging of a system occurs in less than 15 minutes.

1.61Disadvantages

Current flywheels have low specific energy. There are safety concerns associated with

flywheels due to their high speed rotor and the possibility of it breaking loose and

releasing all of it's energy in an uncontrolled manner. Flywheels are a less mature

technology than chemical batteries, and the current cost is too high to make them

competitive in the market.

2.1 Recent developments

Mission critical technology programs are recently focused on storing energy

more efficiently using flywheel than rechargeable chemical batteries while also

providing some control advantages. Flywheel is essentially a simple device for

storing energy in a rotating mass has been known for centuries. It is only since

the development of high-strength materials and magnetic bearings that this

technology is gaining a lot more attention. Exploration of high-strength materials

allows designers to reach high operating speeds, yielding more kinetic energy.

Using magnetic bearings make it possible to reach high operating speeds

providing cleaner, faster and more efficient bearing equipment at extreme

temperatures. Recently designed flywheels could offer orders of magnitude

increases in both performance and service life and in addition, large control

torques and momentum storage capability for spacecraft, launch vehicles,

aircraft power systems and power supplies

The flywheel system mainly consists of flywheel rotor, motor/generator,

magnetic bearings, housing and power transformation electronic system In

the development of the flywheel, current researches have focused on

increasing the performance while meeting the safety considerations, i.e.,

material, housing and bearing failures. Investigation of energy storage and

failure considerations starts with the calculation of kinetic energy.

2.2Theoretical analysis

The kinetic energy stored in a rotating mass is given as,

(1)

(2)

where x is the distance from rotational axis to the differential mass dmx.

where I is the mass moment of inertia and ω is the angular velocity. Mass

moment of inertia is obtained by the mass and geometry of the flywheel and

given as,

For solid cylindrical disk, I is given as,

(3)

where m is the mass and r the radius of the flywheel. Specific energy Ek,m is

obtained by dividing Ek by the mass to give:

(4)

If Ek, is multiplied by the mass density ρ of the flywheel the energy density is

obtained:

(5)

In this context, the design challenge is to maximize either Ek,m or Ek,v, while

satisfying the stress constraints. Tangential and radial stresses are given for

cylindrical flywheel geometry [10] where the outside radius (ro) is assumed to

be large compared to the flywheel thickness (t) ro 10t;

(6

(7

After careful examination of these formulations, it could be observed that

mainly three fully-coupled design factors have significant effect in the overall

performance of flywheels as depicted in Fig. 1.

• Material strength; basically stronger materials could undertake large

operating stresses, hence could be run at high rotational speeds allow ing to

store more energy.

1• Rotational speed; directl y controls the energy stored, higher speeds

desired for more energy storage, b ut high speeds assert excessive loads

on b oth flywheel and bearings during the shaft design.

2• Geometry; controls the S pecific Energy, in other words, kinetic

ener gy storage capability of the fl ywheel. Any optimization effort of

flywheel cross-section may contribute su bstantial improvements in kinetic

energy sto rage capability thus reducing bo th overall shaft/bearing loads

and material failure occurences.

Fig. 2.1. Fully-coupled flyw heel operating characteristics.

INTRODUCTION TO CATIA

CATIA (Computer Aided Three-dimensional Interactive Application) is

a multi-platform CAD/CAM/CAE commercial software suite developed by the

French company Assault Systems. Written in the C++ programming language,

CATIA is the cornerstone of the Assault Systems product lifecycle management

software suite.

CATIA competes in the CAD/CAM/CAE market with Siemens NX,

Pro/E, Autodesk Inventor, and Solid Edge as well as many others.

Table 3.1: Details of CATIA

3.1 HISTORY OF CATIA

Developer(s) Dassault Systems

Stable release V6R2011x / November 23,

2010

Operating system Unix / Windows

Type CAD software

License Proprietary

Website WWW.3ds.com

CATIA started as an in-house development in 1977 by French aircraft

manufacturer Avions Marcel Dassault, at that time customer of the CADAM

CAD software to develop Dassault's Mirage fighter jet, then was adopted in the

aerospace, automotive, shipbuilding, and other industries.

Initially named CATI (Conception Assisted Tridimensionnelle

Interactive - French for Interactive Aided Three-dimensional Design) - it was

renamed CATIA in 1981, when Dassault created a subsidiary to develop and

sell the software, and signed a non-exclusive distribution agreement with IBM.

In 1984, the Boeing Company chose CATIA as its main 3D CAD tool,

becoming its largest customer.

In 1988, CATIA version 3 was ported from mainframe computers to

UNIX.

In 1990, General Dynamics Electric Boat Corp chose CATIA as its main

3D CAD tool, to design the U.S. Navy's Virginia class submarine.

In 1992, CADAM was purchased from IBM and the next year CATIA

CADAM V4 was published. In 1996, it was ported from one to four UNIX

operating systems, including IBM AIX, Silicon Graphics IRIX, Sun

Microsystems SunOS and Hewlett-Packard HP-UX.

In 1998, an entirely rewritten version of CATIA, CATIA V5 was

released, with support for UNIX, Windows NT and Windows XP since 2001.

In 2008, Dassault announced and released CATIA V6. While the server

can run on Microsoft Windows, Linux or AIX, client support for any operating

system other than Microsoft Windows is dropped.

3.1.1 Release History

Name/Version Latest Build

Number

Original Release

Date

Latest Release

Date

CATIA v4 R25 1993 January 2007

CATIA v5 R20 1998 February 2010

CATIA v6 R2012 29/05/2008 May 2011

Table 3.2: versions of CATIA

3.2 SCOPE OF APPLICATION

Commonly referred to as 3D Product Lifecycle Management software

suite, CATIA supports multiple stages of product development (CAx), from

conceptualization, design (CAD), manufacturing (CAM), and engineering

(CAE). CATIA facilitates collaborative engineering across disciplines,

including surfacing & shape design, mechanical engineering, equipment and

systems engineering

3.2.1 Surfacing & Shape Design

CATIA provides a suite of surfacing, reverse engineering, and

visualization solutions to create, modify, and validate complex innovative

shapes. From subdivision, styling, and Class A surfaces to mechanical

functional surfaces.

3.2.2 Mechanical Engineering

CATIA enables the creation of 3D parts, from 3D sketches, sheet metal,

composites, and molded, forged or tooling parts up to the definition of

mechanical assemblies. It provides tools to complete product definition,

including functional tolerances, as well as kinematics definition.

3.2.3 Equipment Design

CATIA facilitates the design of electronic, electrical as well as

distributed systems such as fluid and HVAC systems, all the way to the

production of documentation for manufacturing.

3.2.4 Systems Engineering

CATIA offers a solution to model complex and intelligent products

through the systems engineering approach. It covers the requirements

definition, the systems architecture, the behavior modeling and the virtual

product or embedded software generation. CATIA can be customized via

application programming interfaces (API). CATIA V5 & V6 can be adapted

using Visual Basic and C++ programming languages via CAA (Component

Application Architecture); a component object model (COM)-like interface.

Although later versions of CATIA V4 implemented NURBS, V4

principally used piecewise polynomial surface. CATIA V4 uses a non-manifold

solid engine.

Catia V5 features a parametric solid/surface-based package which uses

NURBS as the core surface representation and has several workbenches that

provide KBE support.

V5 can work with other applications, including Enova, Smarteam, and

various CAE Analysis applications.

3.3 SUPPORTED OPERATING SYSTEMS AND PLATFORMS

CATIA V6 runs only on Microsoft Windows and Mac OS with limited

products.

CATIA V5 runs on Microsoft Windows (both 32-bit and 64-bit), and as of

Release 18Service Pack4 on Windows Vista 64.IBM AIX, Hewlett Packard HP-

UX and Sun Microsystems Solaris are supported.

CATIA V4 is supported for those Unixes and IBM MVS and VM/CMS

mainframe platforms up to release 1.7.

CATIA V3 and earlier run on the mainframe platforms.

3.4 NOTABLE INDUSTRIES USING CATIA

CATIA can be applied to a wide variety of industries, from aerospace

and defense, automotive, and industrial equipment, to high tech, shipbuilding,

consumer goods, plant design, consumer packaged goods, life sciences,

architecture and construction, process power and petroleum, and services.

CATIA V4, CATIA V5, Pro/E, NX (formerly Unigraphics), and Solid Works are

the dominant systems.

3.4.1 Aerospace

The Boeing Company used CATIA V3 to develop its777 airliner, and is

currently using CATIA V5 for the787 series aircraft. They have employed the

full range of Dassault Systems' 3D PLM products — CATIA, DELMIA, and

ENOVIALCA — supplemented by Boeing developed applications.

The development of the Indian Light Combat Aircraft has been using CATIA

V5.

Chinese Xian JH-7 A is the first aircraft developed by CATIA V5, when the

design was completed on September 26, 2000.

European aerospace giant Airbus has been using CATIA since 2001.

Canadian aircraft maker Bombardier Aerospace has done all of its aircraft

design on CATIA.

The Brazilian aircraft company, EMBRAER, use Catia V4 and V5 to build all

airplanes.

Vought Aircraft Industries use CATIA V4 and V5 to produce its parts.

The British Helicopter company, Westland, use CATIA V4 and V5 to

produce all their aircraft. Westland is now part of an Italian company called

Finmeccanica the joined company calls themselves AgustaWestland.

The main supplier of helicopters to the U.S Military forces, Sikorsky

Aircraft Corp., uses CATIA as well.

3.4.2 Automotive

Many automotive companies use CATIA to varying degrees, including

BMW, Porsche, Daimler AG, Chrysler, Honda, Audi, Jaguar Land

Rover Volkswagen , Bentley Motors Limited, Volvo, Fiat, Benteler AG, PSA

Peugeot Citroën, Renault, Toyota, Ford, Scania, Hyundai, Skoda Auto, Tesla

Motors, Valmet Automotive, Proton, Tata motors and Mahindra & Mahindra

Limited. Goodyear uses it in making tires for automotive and aerospace and

also uses a customized CATIA for its design and development. Many

automotive companies use CATIA for car structures — door beams, IP

supports, bumper beams, roof rails, side rails, body components — because

CATIA is very good in surface creation and Computer representation of

surfaces. Bombardier Transportation, Canada is using CATIA software to

design its entire fleet of Train engines, Coaches.

3.4.3 Ship building

Dassault Systems has begun serving shipbuilders with CATIA V5 release 8,

which includes special features useful to shipbuilders. GD Electric Boat used

CATIA to design the latest fast attack submarine class for the United States

Navy, the Virginia class . Northrop Grumman Newport News also used CATIA

to design the GeraldR . Ford class of super carriers for the US Navy.

3.4.4 Industrial Equipment

CATIA has a strong presence in the Industrial Equipment industry.

Industrial Manufacturing machinery companies like Schuler and Metso use

CATIA , as well as heavy mobile machinery and equipment companies like

Claas, and also various industrial equipment product companies like Alstom

Power and ABB Group.

3.4.5 Other

Architect Frank Gehry has used the software, through the C-Cubed

Virtual Architecture company, now Virtual Build Team, to design his award-

winning curvilinear buildings. His technology arm, Gehry Technologies, has

been developing software based on CATIA V5 named Digital Project. Digital

Project has been used to design buildings and has successfully completed a

handful of projects.

According to the described procedure the gear pair with the following

parameters was modeled using CATIA V5R12. Modeling of gear using the

CATIA consists of two steps, one is part design and another Assembly design.

Part and Shape design are the basic modules of design in CATIA software.

They are based on several tools for easy and qualitative modeling of any kind of

machine elements. First step of design any part is to define position (plane) of

Sketch and to draw profile in chosen Sketch. Some operations consist in adding

material, others in removing material for example Create a Pad, Pocket, Shaft,

Groove, Hole, Slot, and Loft etc.

DESIGNING OF FLYWHEEL IN CATIA

STEP1:start--->mechanical design---->part design

STEP2:select an axis plane then go to 2D plane by using sketch tool

STEP3:draw a circle with required radius and come to 3D plane by using exit work bench

STEP4:add material to circle by using pad tool up to required thickness

STEP5: make a hole with circle command in sketcher workbench and at centre for shaft by using pocket tool

STEP6:add some material around the inner hole to required thickness

STEP7:Remove the material from wheel at required levels by using pocket tool by making dimensions in sketch

STEP8: make chamfering using chamfer command

STEP9:sketch--->make asmall hole beside shaft hole---->remove the material by using pocket tool

STEP10:by using circular pattern definition make holes in circular transformation form command

STEP11:make teeth on flywheel by using pocket tool and make around the wheel by using circular pattern definition

STEP12:Remove the material by using pocket tool at desired levels

STEP13: make chamfering by using chamfering tool

STEP14:it is final view of fly wheel

STEP14:After applying material

STEP15:four side view of fly wheel for different angle view

STEP17:Wireframe view of flywheel

STEP18:Final view of flywheel

CONCLUSION

A flywheel used in machines serves as a reservoir which stores energy during

the period when the supply of energy is more than the requirement and releases

it during the period when the requirement of energy is more than supply.

In our project we have designed a flywheel used in a multi cylinder petrol

engine using theoretical calculations. 2d drawing is created and Modelling of

flywheel is done using CATIA V5 R20, using sketcher workbench and part

design workbench.

In this work bench using different sketch tools in sketcher workbench and 3D

commands in part design workbench, we designed IC engine flywheel.

Based on the above work of flywheel and its optimization methods the

following design is completed.

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