The objectives, approach, and FY'78 progress and results of the Aerodynamic Resistance Reduction work element of the Electric and Hybrid Vehicle System R and D Project are described. The generation of an EHV aerodynamic data base was initiated by conducting full-scale wind tunnel tests on 16 vehicles. Zero-yaw drag coefficients ranged from a high of 0.58 for a boxey delivery van and an open roadster to a low of about 0.34 for a current 4-passenger prototype automobile which was designed with aerodynamics as an integrated parameter. A subscale investigation was performed in order to identify any characteristic effects of aspect ratio or fineness ratio which might appear if electric vehicle shape proportions were to vary significantly from current automobiles. Some preliminary results are presented which indicate a 5 to 10% variation in drag over the range of interest. A rigorous procedure was developed in order to determine effective drag coefficient wind-weighting factors over J227a driving cycles in the presence of annual mean wind fields. The applications of this procedure allows a user to accurately account for statistical wind effects in computer simulations by means of a modified constant-drag coefficient. Such coefficients, when properly weighted, were found to be from 5 to 65% greater than the zero-yaw drag coefficient in the cases presented. In order to guide preliminary design work, a review of the general principles of the aerodynamic design of automobiles is presented along with several drag-estimating procedures and commentary. Also included is a vehicle aerodynamics bibliography of over 160 entries, in six general categories.

  • Corporate Authors:

    Jet Propulsion Laboratory

    California Institute of Technology, 4800 Oak Grove Drive
    Pasadena, CA  United States  91103

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  United States  20585
  • Publication Date: 1979-4

Media Info

  • Pagination: 85 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00198465
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: EM-78-I-01-4209
  • Files: TRIS
  • Created Date: Oct 17 1981 12:00AM