Wind-tunnel study of the effect of gap flow and gap seals on the aerodynamic drag of tractor-trailer trucks

Conference · Fri Dec 01 04:00:00 EST 1978 · J. Fluids Eng.; (United States)

OSTI ID:6197203

Buckley, Jr, F T; Marks, C H

The effect of gap width on the aerodynamic drag of a cab-over-engine tractor-trailer combination has been investigated for full-scale gap widths ranging from 0.61 m (24 in.) to 1.83 m (72 in.) over a yaw angle range of 0 to 20 deg. The average drag on the vehicle was found to increase by 16% as the gap width increased from 0.61 m to 1.83 m. Drag reductions were found when a vertical seal was placed along the vehicle center line between the tractor and the tailer. Generally, the drag reduction increased as the percentage of gap width that was sealed increased, and as the yaw angle increased. The average drag coefficient reduction provided by a full gap seal increased from 0.02 to 0.05 as the gap width increased from 0.61 m to 1.4 m and then decreased slightly for gap widths up to 1.83 m. The effect of vehicle configuration on gap seal effectiveness was evaluated for a gap width of 1.3 m (51 in.) using models of six different tractors and two different trailers. The average drag coefficient reductions that were found ranged from 0.04 to 0.08 with 83% of the data being either 0.04 or 0.05. It is shown that the use of gap seals on the nearly half-million vehicles which comprise the nation's long-haul trucking fleet can result in the conservation of about 1.4 x 10/sup 9/ liters (0.37 x 10/sup 9/ gal) of motor fuel each year.

• Research Organization: Univ. of Maryland, College Park
• OSTI ID: 6197203
• Conference Information: Journal Name: J. Fluids Eng.; (United States) Journal Volume: 100:4
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320203* -- Energy Conservation
Consumption
& Utilization-- Transportation-- Land & Roadway
AERODYNAMICS
CONFIGURATION
DESIGN
DRAG
ENERGY CONSERVATION
ENERGY CONSUMPTION
FLUID MECHANICS
FUEL CONSUMPTION
MECHANICS
MOCKUP
PERFORMANCE TESTING
STRUCTURAL MODELS
TESTING
TRUCKS
TUNNELS
VEHICLES
WIND TUNNELS