Design Team # 3 Shell Eco Marathon (Super-mileage Car) Members: Hussain Abdellatif Sohaib Syed Alam...
-
Upload
kayden-parkman -
Category
Documents
-
view
215 -
download
1
Transcript of Design Team # 3 Shell Eco Marathon (Super-mileage Car) Members: Hussain Abdellatif Sohaib Syed Alam...
Design Team # 3Shell Eco Marathon (Super-mileage Car)
Members:Hussain Abdellatif Sohaib Syed AlamJulius Mantolino
Adam ProcterSupervisor:
Dr. Alex Kalamkarov
Background Scope Design Requirements The Design Current Project Status Future Considerations Design Requirements Check Budget Acknowledgements
Outline
2
Americas Shell Eco-Marathon Competitionnot to go fast but to use least amount of fuel
Houston, Texas – (March 29-April 1 2012) 2009 Dalhousie Team - 12th Place (819mpg) Core Super mileage Team with 4 volunteers
◦ Cover◦ Steering◦ Driver
Background
3
Ultimate Goal: Achieve ≥ 900 mpg Qualify/Compete for Shell Eco Marathon:
◦ Geometric Limitations ◦ 4 stroke IC Gasoline Engine
Increased Fuel Efficiency Lighter Powertrain Lighter Chassis Lighter & More Efficient Wheels
Design Requirements
4
Engine Fuel Injection System Powertrain
◦ Transmission◦ Bearings◦ Clutch
Chassis Wheels
The Design – Our Scope
5
Rolling Resistance◦ Reduction in weight◦ More efficient wheels
Aerodynamics◦ Reduction in frontal area
The Design -Challenge
6
Direct Fuel Consumption Options Considered:
◦ Old 35cc Honda◦ Old 50cc XF Yamaha ◦ New 35cc Robin Subaru
Honda 35cc [1]
Robin Subaru 35cc [2]
50cc XF Yamaha
Engine
7
Parameter 35cc Honda[1] 35cc Subaru[2] 50cc Yamaha[3]
Weight [kg] 3.00 2.80 11.34
Displacement [cm3] 35.8 33.5 49
Max. Power [HP @ RPM]
1.3 @ 7000 1.6 @ 7000 5 @ 8000
Max. Torque [Nm @ RPM]
1.6 @ 5500 1.76 @ 5000 4.6 @ 6500
Max. Power to Weight Ratio [HP/kg]
0.43 0.57 0.44
Past Experience Underpowered N/A Overpowered
Engine Selected : 35cc Robin Subaru
Engine - Selection
8
One-way Needle Bearing
Reused electric motor from Yamaha
Gear reduction
Engine Modifications-Electric Starter
9
Requirement: Max. Noise Level <90 dB
Stock Muffler:◦ Lower Efficiency
Glass Pack Muffler:◦ Perforated Design◦ Packing diffuses sound◦ Less restriction Glass Pack Muffler
[4]
Engine Modifications-Muffler
10
Possible fuel delivery methods:◦ Carbureted◦ Port Fuel Injection◦ Direct Injection
Direct Injection is not Viable:◦ Requires mechanical fuel pump (competition
rules)◦ Complex
Fuel Delivery System
11
Carburetor Port Fuel Injection
Advantages No cost Time savings
Advantages Controlled amounts of fuel Conversion kit can be readily
purchasedDisadvantages Low efficiency No control on optimum fuel
consumption
Disadvantages Cost (~$800) Needs pressurized system Calibration and fine tuning
Selected: Port Fuel Injection
Fuel Delivery System-Selection
12
Replace carburetor Conversion kit purchased from Ecotron: Key components:
◦Oxygen (O2) Sensor
◦Fuel Injector◦Programmable Engine Control Unit (ECU)◦Fuel Pressurization System◦Throttle Body
Fuel Delivery System-Electronic Fuel Injection
13
Control parameters as required
Engine Control Unit (ECU)
Throttle Position
Inlet Air Pressure
Fuel Injector
Inlet Air Temp.
Exhaust Temp.
Crankshaft Position
Engine Kill Switch
Programmable Control
Parameters
Sensors – Input Controlled Output
Exhaust O2
Fuel Delivery System-Electronic Fuel Injection
14
Spark Timing
Fuel Pressurization System [5]
Fuel Delivery System-Pressurization
15
Transmits power from engine Require minimum power losses Provide sufficient torque Best Efficiency Point (BEP) ∼ 5000 RPM
◦ Provided by bsfc curve◦ To be verified with testing
Calculate suitable gear ratio:
Powertrain
16
Direct Drive Variable Transmission
Advantages: Simple design Cheap Lightweight
Advantages: Vary the gear ratio to the wheel Change torque at wheel
Disadvantages: Can’t run at BEP Start-up load
Disadvantages: Expensive Complicated and heavy Requires gear shifting
Transmission Type Selected : Direct Drive
Powertrain- Transmission
17
Components:◦Gear Reduction Method Two Stages
◦Bearing◦Clutch
Powertrain
18
Roller Chain Timing Belt Planetary Gearbox
Advantages: Easy to design Cheap
Advantages: Cheap Light weight
Advantages: Compact Design High reliability
Disadvantages: Weight Large sprockets Space
Disadvantages: Pulleys sizes Space
Disadvantages: Cost (~$800) Medium Weight
Primary Stage Selected : Planetary Gearbox
Powertrain – 1st Stage
19
Planetary Gearbox for 1st stage Purchase Neugart PLE60-20 Planetary
Gearbox from Wainbee Ltd.◦ 94% efficient◦ 20:1 gear ratio◦ Continuous torque 44 N.m.
Roller Chain and Sprockets for 2nd stage
Powertrain - Overall
20
Planetary Gearbox for 1st stage Roller Chain and Sprockets for 2nd stage
Powertrain - Overall
21
Powertrain - Bearings
Ceramic (Si3N4) Ball Bearings [6] Steel Bearings
Advantages:
Significantly reduced weight;
(0.5 x steel)
30% the friction of steel
Provides smoother operation
Advantages:
Cheap
Disadvantages:
Expensive (10 x price of steel)
Disadvantages:
Heavier
More friction
Requires lubrication
Bearings Selected : Ceramic Ball Bearings22
Centrifugal [7]
Friction Plate [8]
Powertrain-Clutch
23
Powertrain-Clutch Selection
Friction Plate Clutch Centrifugal Clutch
Advantages:
Flexibility in engaging
Less power losses
Greater torque capacity
Advantages:
Light weight Compact
Automatic engagement
Disadvantages:
Heavier
Space
Risk of stalling
Disadvantages:
Power losses during slippage
Spares
Clutch Selected : Centrifugal Clutch24
Powertrain-Torque Calculations
Engine is not overloaded
0.00 5.00 10.00 15.00 20.00 25.00 30.000.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Torque@ Clutch Vs. Car Speed (with G = 20)
Car Speed (mph)
Torq
ue @
Clu
tch (
Nm
)
0.00 5.00 10.00 15.00 20.00 25.00 30.000.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
Power@ Clutch Vs. Car Speed
Car Speed (mph)
Pow
er
(hp)
25
Design Requirement: Lighter chassis◦ Aluminum Alloy 6061-T6◦ Yield strength = 275 MPa
Weight estimate entire car (with driver) ~ 90kg
Withstand static load of 700N on roll bar
Chassis-Selection
Past team Selected• 1’’ OD by 0.125” thick• Cross section area = 0.34 in2
• 1-1/4’’ OD by 0.065” thick• Cross section area = 0.24 in2
30% weight reduction per unit length
26
Chassis – Rear Loading
Max. Stress: 55 MPa
27
Chassis – Side Loading
Max. Stress: 75 MPa
28
Chassis – Pull Loading
Max. Stress: 50 MPa
29
Chassis – Push Loading
Max. Stress: 43.8 MPa
30
Wheels
31
3 wheels: 2 in front, 1 in back
Front Wheel Design◦ Lighter◦ No Internal Ratchet
Back Wheel Design◦ Internal Ratchet◦ Heavier
Back vs Front Wheel Assembly [9]
3 wheels: 2 in front, 1 in back
Wheels
Past team Selected• Front Wheels:
o Small (406 x 44c)• Back wheels:
o Small (406 x 44c)o Back Wheel Design
• Front wheels:o Larger (700 x 25c)
• Back wheels:o Larger (650 x 25c)o Front Wheel Design
Front Wheel Assembly:• Lighter
Larger Rim Size:• Less Bearing Loss
32
Incorporate Sprag Clutch in Back Wheel
Disc Brakes:◦ Reusing from past team
◦ Consistent brake performance
Hubs & Spokes to be purchased
Wheels
33
Past:◦ Michelin road tires
Selected:◦ Continental GatorSkin tires◦ Higher inflation pressure
150 psi vs. 60 psi Lower rolling resistance
◦ Flat and puncture resistant◦ Durable
Wheels
Michelin Tires [10]
GatorSkin Tire [11]
34
Wheels
35
Purchased:◦ Robin Subaru 33.5cc engine◦ Electronic Fuel Injection (EFI) kit◦ PLE60-20 Planetary Gearbox◦ Aluminum tubing for chassis
Designed:◦ Power Train Components◦ Electric Starter Assembly◦ Chassis Main Frame Body
Project Status
36
Achieved Already Qualify/Compete for Shell Eco Marathon
◦ Geometric Limitations◦ 4 stroke IC Gasoline Engine
Lighter Powertrain (Centrifugal)
Lighter Chassis (30% reduction)
To Be Achieved: Increased Fuel Efficiency - to be confirmed with dyno
Lighter & More Efficient Wheels
Achieve ≥ 900 mpg - TBD
Design Req. Check
37
Assemble Power Train Assemble Power Train, Steering & Cover
onto Chassis Purchase Wheels & Wheel Components Obtain Engine Curves with Dyno:
◦ Carburetor◦ Fuel Injection
Fine Tune ECU Programmable Parameters Dyno Vehicle @ Wheels
Future Considerations
38
Engine $425
Fuel Injection System $586
Drivetrain & Clutch (estimate) $2000
Chassis $500
Wheels $2500
--------------------------------------------- Total (15% Contingency) ~ $7000
Budget
39
We would like to thank: Dr. Julio Militzer Dr. Alex Kalamkarov Albert Murphy Mark MacDonald Angus MacPherson Peter Jones Allison Chua, Drew Moores, Ryan Louie &
Dainis Nams
Acknowledgments
40
We Thank Our Sponsors
Acknowledgements - Sponsors
41
[1] http://robinamerica.com/pspecsheet [2] http://www.baileysonline.com/itemdetail[3] http://www.elsberg-tuning.dk/yamaha.html[4] http://auto.howstuffworks.com/muffler5.htm[5] http://poisson.me.dal.ca/~dp_09_15/docs/Fall%20Build%20Report.pdf[6] http://www.vxb.com/page/bearings/CTGY/CeramicBallBearings[7] http://auto.howstuffworks.com/clutch1.htm[8] http://auto.howstuffworks.com/clutch1.htm[9] http://www.qbike.com/cgi-bin/find.cgi?st=road+wheel[10] http://www.michelin.ca/[11]
http://www.mec.ca/AST/ShopMEC/Cycling/TiresTubesWheels/RoadTires/PRD~5005-157/continental-ultra-gatorskin-700-x-28-wire-tire.jsp
References
42
Questions ?
43
Engine Specs Load Torque Assumptions Bearings Bearing, Output Shaft FEMS Starter Assembly FEM
Back Up Material
44
Engine Specifications
45
[ref] – common CD used in old 90’s cars - the max. allowed in competition - frontal area of around (19inx28in)
Torque Calculations (1)
46
Torque Calculations (2)
0.00 5.00 10.00 15.00 20.00 25.00 30.000.000
1.000
2.000
3.000
4.000
5.000
6.000
Torque Load @ Wheel Vs. Car Speed
RollDrag
Car Speed (mph)
Torq
ue (N
m)
47
Torque Calculations (3)
= 48.15 g,
, , [ref] [ref]
Engagement speed
SlipPeriod
Max. Clutch Torque
Clutch “Bites” Clutch transmits engine torque
48
BearingsCeramic (Si3N4) Ball Bearings Steel Bearings
Advantages:
Significantly reduced weight; density of
Si3N4 is 3.2 g/cm3 versus 7.8 g/cm3 of steel
Co-efficient of friction is 30% that of steel
Less lubrication required Can operate at
higher speeds (20% to 40% higher)
Smoother operation because modulus of
elasticity higher (stiffer) than steel; 320 GPa
vs 200 GPa – less deformations leading to
less vibrations
Advantages:
Cheap
Better impact loading handling
Disadvantages:
Expensive (10 times the cost of steel
bearings)
Disadvantages:
Heavier
Higher co-efficient of friction
Need for lubrication
More vibrations and rocky operation
Ball Bearings Selected : Ceramic Ball Bearings
49
Power Train Stresses
50
Starter Mount Stresses
51