Axle Temperature Control Progress Report

Team MembersLee ZimmermanBoun Sinvongsa

Emery FreyMike Erwin

Industry AdvisorDave Ruuhela, Daimler Trucks North America

Academic Advisor Lemmy Meekisho

February 28, 2011

Introduction 2.25% of energy required to operate

a truck at a steady highway speed is lost in the drive train

Increasing the lubricant fluid temp reduces the energy loss

A 1% improvement in efficiency would save each truck $800 per year

Final PDS SummaryPerformance

Customer Requirement Metric Target Basis Verification Priority

DTNA Device is to achieve and maintain axle lube temperature Fluid Temp

65-80°C when Ambient is above 0°C and 50-65°C when Ambient

is as Low as -15°CCustomer Data Test High

End User Net Vehicle Efficiency Increase-ΔKW(Drivetrain

Loss)/ΔKW(Energy Consumption)

>0 Customer Data Comparison High

DTNA Uses existing sources of energy Y/N Yes Customer Data Comparison High

DTNA Device is to heat the axle lube at a specified rate Fluid Temp 2°C/min average minimum Customer Data Test High

Reliability and Quality

DTNA Device will not overheat axle lube Fluid Temp Max Lube Temperature of 120°C Customer Data Test High

Safety

DOT Device minimizes chance of igniting. Temperature / Spark 150 °C / None Department of

Transportation Test High

DTNA Device minimizes chance of oil spill Y/N Yes Customer

Feedback Analysis High

Cost of production per part (material and labor)

DTNA Device to be cost effective Rate of return < 2 years Customer Requirement Analysis High

Gantt Chart

External Search Toyota Prius exhaust gas exchanger PADI Inc. Insulation Jackets E.J. Bowman Heat Exchangers Wolverine Engine Oil Heaters

Internal Search Heat Exchanger

• Exhaust Gas or Engine Coolant Heat Sources

Electric Heater• Heating Element Inside Differential

Passive Insulation

Active Insulation• Insulation with a heat management solution

Design Evaluation1 2 3 2 1 3 2

Ramp-up Rate

Accurate ΔT

Net Efficiency Cost Weight Reliability Safety Total Weighted

Total

Coolant Heat Exchanger 3 3 4 2 1 1 1 15 31

Exhaust Heat Exchanger 4 4 4 1 2 2 2 19 38

Electric Heater 5 5 1 3 5 4 4 27 49

Passive Insulation 1 1 5 5 5 2 5 24 49

Active Insulation 5 5 4 2 3 4 4 27 54

Risk Evaluation

Design is highly dependant on assumptions and difficult to model. Testing of assumptions will be key.

Reliability and cost considerations make more complex designs less feasible

Progress on Detailed Design

To get a first approximation of insulation effectiveness, a simplified spherical model was used.

Calculations

Calculations

Controlled Cooling

If insulation works as well as expected the fluid would potentially overheat on hot days

The fluid temperature could be maintained in the specified range by controlling forced convection

Forced Convection Control A valve/flap mechanism would

provide temperature control with minimal power use.

Conclusion While the insulation is expected be

sufficient for warming the fluid, a cooling system will need to be designed

Future testing on an operating axle will provide information on the most effective locations for the cooling system and confirm the effectiveness of insulation

Questions?