P16462: Wind

Energy Base

StationSarah Collmus // Laura Arciniegas // Kevin Larkin // Kevin Collins //

Suk Lee // Aleksandr Kim// Michael Ostaszewski

Background

Agenda

Background Problem Statement // Customer Requirements // Phase I

System Analysis HoQ // Functional decomposition

Concepts Morph Chart // Design Concepts // Pugh Chart // System

Architecture // Feasibility Analysis // Risk Management

Phase III and Beyond Test Plan Outline // Test Layout // Phase II //

Phase III // Deliverable Completion Plan

Problem StatementCurrent wind turbines are very large and limited in their size due to the stresses they create on the structural supports. An alternative is to use a glider tethered to a base station. This results in ~90% reduction in material usage and allows for a more consistent power output as winds are generally more stable at higher altitudes.

The goal of this effort is to design a base station for a tethered glider flying in a 360° horizontal path to prove the feasibility of the alternate wind energy harvesting method.

GE Wind Power Turbines

Ampyx Power Concept

Customer Requirements

Phase I Plan

System Analysis

House of Quality

Functional Decomposition

Concept & Architecture Development

Morph Chart (Page 1)

Morph Chart (Page 2)

Design Concepts

1: External Wired Motor

2: Heavy Battery Motor

3: Crank & Motor

4: Pinned Reel with Crank Drum

External Wired Motor

Base:

ring , four columns, metal

Plane:

two point bridle, wheels

External components:

DC motor, power outlet

Heavy Battery Motor

Base:

spherical bushing, 2 columns, steel

Plane:

four point bridle, wheels, hooks

External components:

DC motor, controls, battery

Crank & Motor

Base:

Wood, 4 columns, ring

Plane:

3 point tether, parachute, glued

External components:

DC motor, power outlet

Pin Reel with Crank Drum

Base:

metal, spherical bushing, 4 columns

Plane:

4 bridle point, wheels, tied

External concept:

Reel, crank

Pugh Chart

Systems Architecture

Feasibility Analysis - Wheels

What is the best method to make contact with the ground?

Most hobby planes have sets of wheels which take the damping of the landing and transfer wind energy into rotational energy. The three wheels are able to balance the plane so that tipping does not occur. Also this method, could be used to launch since with appropriate wheel bearing the plane could reach high speeds. The wheel in the front should be sized so that it holds 5%-20% of the load while the back two wheels should distribute the remaining weight.

Mohammad Sadraey [Daniel Webster College]

Feasibility Analysis - Electrical HousingTo make Base station/Glider balanced and stable, is it better to make a “house” for electrical components?

In the previous plane, the parts were not distributed the weight evenly but a housing will allow easier testing and protection from the environment and surrounding areas.

Also a motor inside the base may cause vibrations that would damage solder points on the control board. So recommend either setting the electrical box or moving the motor outside the base.

Coating

Weight Size Price Ease of Build

single board copper 1 oz 2.9”*5.9” $2.95 Easy

double board

copper 2 oz 2.9”*5.9” $3.95 Complicated

Feasibility - Motor Transfer Function Can the plane handle immediately being tugged by the tether? How do we prevent this?

This isn’t an ideal situation so a transfer function or a DC programmable ramp up needs to be in place to increase the voltage. This can be achieved by a programmable ramp up such as the AP4830 which is a DC programmable up down ramp generator. The other way is using a sinusoidal input and a transfer function. Assuming a 10% overshoot, two pole system with a gain of k where k is the value that the motor expects.

The final transfer function is,

G(s) = k/(s^2 +a1s + a2)

Where a1 = 8.00 and a2 = 102.2

Those values will be determined by the RLC components internal to the circuit.

Feasibility - Tensions on Plane How much tension force can the foam glider support without failing, and how much tension force can be anticipated?

As the type of EPO foam is currently unknown, its properties and strengths are variable. However, the anticipated tension force can be estimated using Glenn Gavi’s 2D simulation. Upon running a series of simulations using inputs similar to our own plane, based on only variations of wind speeds, it outputted simulated flight patterns over time and tension.

The tensions it outputted were large, but have no reference without knowing the strengths of the EPO foam.

with wind speeds at 10 m/s yielding an oscillating tension force of up to 2,000 N

with wind speeds at 5 m/s, the tension forces oscillated up to 460 N

with wind speeds at 2 m/s, the tension peaks at the first cycle at 114 N, but then decays with a peak of 70 N after 6 cycles.

Calculations of free flight indicated that the plane needs to fly at a relative speed of 7.8 m/s to maintain lift.

Feasibility - Tensions on Plane (Continued)How much tension force can the foam glider support without failing, and how much tension force can be anticipated?

It can be expected that the bridle system will distribute this load (not necessarily evenly) on the glider and not necessarily as a point force at the connection. It also raised the question of whether the plane could maintain flight and structure through tethered, but non reeled in flight.

This raises another question: “What is the minimum speed the plane must fly at to maintain lift against the opposing tension force?”

Feasibility Analysis - Weight of BaseHow heavy does the base need to be to remain securely on the ground? Can the plane survive the tension force applied by the tether?

Using the free body diagrams presented here,

calculations can be done to determine whether or

not the plane and the base can withstand the forces.

The MatLab simulation shows that the base and the

plane could experience up to 1500 N of force.

A major assumption made in this drawing is the

purely vertical alignment of the forces. Horizontal

components may need to be considered as well.

Feasibility Analysis - Resource CommitmentAre the launch and land systems worth the financial and the man hour commitment? Is it worth using a motor instead of human power at this early state of analysis?

○ Most gliders should be capable of being launched by hand and landing on their belly on the grass. Any modifications add weight to a glider that isn’t able to generate much lift, Especially if it will be attached to a long tether.

○ Our current project should be focused more on getting a glider flying in its intended path before adding any additional components to the base. The simulation also shows that tension forces can reach 1000N and that can require a lot of power to reel in using a motor. A more powerful motor adds additional strain on the budget (25% is already used)

Feasibility Analysis - Circular Tether GuideWhat circular tether guide (ring or bushing) is most effective? Can this be figured out without wasting money with prototyping?

Steps to solve:

Research cost of needed materials

Look to see if similar systems are laying around the lab

Attempt to figure out cheap prototyping vendors/methods

Draw in CAD and do a stress analysis

Nothing similiar seen in lab. RIT machine shop would be the quickest and cheapest vendor since it is in-house. The second question can be answered during Phase III.

Research:

Ring system would need to be entirely machined and would need to be lubricated to cut down on friction.

Ball bearings: open or shielded will have less friction than a sealed ball bearing. Shielded can be between $8-$40, open $4-$35

Would need to machine a guide tube, lubricate

Spherical bushing, $13, also would need to machine a guide tube

Re-Evaluated Design

Risk Management

Phase III and Beyond

Test Plan OutlineBridge Connection Test

Test bridle strengthMeasure wing deflection

Tether Strength TestTest tether strength

Base/Reel Durability TestTest the strength of the reel systemTest base structural stabilityTest base’s connections to the ground

Wheel Durability TestTest wheel durabilityTest security of the connection between plane and wheels

Bridle Connection Test

Tether Strength Test

Wheel Durability Test

Base/Reel Durability Test

What a Test Would Look Like(Page 1)

What a Test Would Look Like(Page 2)

Testing Safety Plan

Established teammates spots (launching, flying, landing)Safety gear for active team members

Base operatorPilotLauncher

Communication lines between members“Spotters” to watch the system and check out surroundingsEstablished area of use, Blood Circle, Caution AreaIf an event is nearby, operate established distance away from any large public gatheringIn case of failure, operating distance from public should provide necessary clearanceLanding and Retrieval Emergency representative in case of accidentWeather Conditions, flight permitting

*Until there is confidence in independent flight, operate under supervision of Dr. Kolodziej and/or Phil Nguyen

Phase II

Phase III

Deliverable Completion Plan

Other Design Considerations

Motor outside base due to vibrations of motor breaking solder connections

Find a way to distribute large tension force throughout the plane better.

The tether material needs to be stronger and lighter than the string we were planning on using because the plane is too light to spin it otherwise

Rechargeable batteries for the plane controller is the most economical and easiest way to go

Thank you!