Accession Number : ADP004791

Title :   Axisymmetric Bluff-Body Drag Reduction through Geometrical Modifications,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER

Personal Author(s) : Howard,F. G. ; Goodman,W. L.

Report Date : AUG 1984

Pagination or Media Count : 11

Abstract : The effect of shoulder radiusing and grooving (longitudinally or circumferentially) the afterbodies of bluff bodies to reduce the base drag at low speeds is discussed. Shoulder radii as large as 2.75 body diameters are examined. Reynolds number based on body diameter varied from 20,000 to 200,000. Results indicate that increasing the shoulder radius to 2.75 body diameters can reduce the drag levels to those of a streamline body having 67 percent greater fineness ratio. For the relatively sharp shoulder case, body drag reductions as large as 50% are obtained using circumferential or longitudinal grooves. (Author)

Descriptors :   *GAS FLOW, *DRAG REDUCTION, GROOVING, AFTERBODIES, STREAMLINE SHAPE, REYNOLDS NUMBER, ASYMMETRY

Distribution Statement : APPROVED FOR PUBLIC RELEASE