Realtime simulation of fuel economy for platooning cars and trucks

1
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
2
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.
3
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, ? weight, area, velocity, air density

4
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.

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The drag of a single body with and without
rounded vertical edges
W H L (w/attachment) 1 1.4 4.2
(4.5)
W Ground Clearance 1 0.28
CD 0.94 ?.02
U? 26 m/s
Re U?W/? 267,000
Blockage corrections based upon local q derived
from wall-static pressure
CD 0.51 ?.01
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Drag versus separation
BLUNT-ROUNDED
BLUNT-BLUNT
ROUNDED-ROUNDED
ROUNDED-BLUNT
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Wind-tunnel truck models
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Total drag summary
BLUNT - ROUNDED
ROUNDED - ROUNDED
BLUNT - BLUNT
ROUNDED - BLUNT
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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.