04a

Real-time simulation of fuel economy for platooning cars and trucks : Real-time simulation of fuel economy for platooning cars and trucks Acquire data on fuel consumption for trucks in platoon operation. Create a real-time simulation of fuel savings for display during DEMO 2003. Provide a predictive model of use to the trucking industry. Jerry Chen & Fred Browand Ground Vehicle Aerodynamics Lab


Collect data on fuel consumption for trucks in platoon operation : Collect data on fuel consumption for trucks in platoon operation Broadcast fuel rate (cm3/sec) and wheel speed outputs on SAE J1939 serial data link are adequate to provide instantaneous fuel consumption in liters/kilometer (or gallons/mile). Cummins estimates absolute accuracy of broadcast fuel rate to be within ± 3% of output value. The relative measurement (for each truck): (fuel consumption)platoon/(fuel consumption)isolation will be much more accurate. Both these measurements must follow one another under identical ambient wind and temperature conditions.


Provide a predictive model of use to the trucking industry : Provide a predictive model of use to the trucking industry Fuel saving in platoon travel arises solely from a decreased aerodynamic drag. Predictive models for fuel savings are related to drag savings. Example: FC = fuel consumption, p-platoon, a-isolation r = rolling resistance, dz/ds = road gradient Wt, S, U, ρ = weight, area, velocity, air density


Provide a predictive model of use to the trucking industry : Provide a predictive model of use to the trucking industry Infer drag changes from changes in fuel consumption for operating platoon. Compare field measurements with our wind tunnel measurements for two close following trucks. Evaluate and resolve inconsistencies.


Slide5 : W: H: L (w/attachment) 1: 1.4: 4.2 (4.5) U = 26 m/s Re = UW/ = 267,000 W: Ground Clearance 1: 0.28 Blockage corrections based upon local q derived from wall-static pressure CD = 0.94 .02 CD = 0.51 .01 The drag of a single body with and without rounded vertical edges


Slide6 : BLUNT-ROUNDED ROUNDED-ROUNDED ROUNDED-BLUNT BLUNT-BLUNT Drag versus separation


Slide7 : Wind-tunnel truck models


Slide8 : Total drag summary BLUNT - BLUNT BLUNT - ROUNDED ROUNDED - ROUNDED ROUNDED - BLUNT


Work effort next 9 months : Work effort next 9 months Acquire additional data from single truck runs, and evaluate data quality. Assist as needed. Be available for wind, temperature measurement. (0-4 months) Acquire data for platoon of trucks, and evaluate data quality. Record wind, temperature. Input data into our most recent display program. (4-9 months) Continue to improve animated display. (0-9 months) Other suggestions. Animation schemes welcome.