AN INVESTIGATION OF DRAG REDUCTION FOR TRACTOR TRAILER VEHICLES WITH AIR DEFLECTOR AND BOATTAIL

A wind tunnel investigation was conducted to determine the influence of several physical variables on the aerodynamic drag of a trailer model. The physical variables included: a cab mounted wind deflector, boattail on trailer, flow vanes on trailer front, forced transition on trailer, and decreased gap between tractor and trailer. Tests were conducted at yaw angles (relative wind angles) of 0, 5, 10, 20, and 30 degrees and Reynolds numbers of 3.58 x 10 to the 5th power 6.12 x 10 to the 5th power based upon the equivalent diameter of the vehicles. The wind deflector on top of the cab produced a calculated reduction in fuel consumption of about 5 percent of the aerodynamic portion of the fuel budget for a wind speed of 15.3 km/hr (9.5 mph) over a wind angle range of 0 deg to 180 deg and for a vehicle speed of 88.5 km/hr (55 mph). The boattail produced a calculated 7 percent to 8 percent reduction in fuel consumption under the same conditions. The decrease in gap reduced the calculated fuel consumption by about 5 percent of the aerodynamic portion of the fuel budget.

• Corporate Authors:

  Center for Research, Incorporated

  Kansas University, 2385 Irving Road
  Lawrence, KS  United States  66045

  National Aeronautics and Space Administration

  600 Independence Avenue, SW
  Washington, DC  United States  20546
• Authors:
  • Muirhead, V U
• Publication Date: 1981-1

Media Info

• Pagination: 68 p.

Subject/Index Terms

• TRT Terms: Aerodynamics; Deflectors; Drag; Fuel consumption; Reduction (Chemistry); Streamlining; Tractor trailer combinations; Trailers; Truck tractors; Vehicle design; Wind; Wind tunnels
• Old TRIS Terms: Boattails; Drag reduction; Flow deflection; Reduction
• Subject Areas: Design; Energy; Highways; Motor Carriers; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00336891
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: NASA-CR-163104 Final Rpt., KU-FRL-406-1
• Contract Numbers: NSG-4021, NSG-4023
• Files: TRIS
• Created Date: Jun 12 1981 12:00AM