Accession Number : ADA194003

Title :   An Assessment of the Drag Reduction Properties of Riblets and the Penalties of Off-Design Conditions.

Descriptive Note : Memorandum rept.,

Corporate Author : ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND)

Personal Author(s) : Gaudet, L

PDF Url : ADA194003

Report Date : Aug 1987

Pagination or Media Count : 22

Abstract : An assessment is given of the performance of riblets in reducing skin friction in turbulent flow. The data of Sawyer and Winter is used to develop skin-friction relationships derived from the velocity profile for a turbulent boundary layer as modified by a riblet surface. The maximum percentage drag reduction is shown to vary with Reynolds number R sub x. At large values of the non-dimensional riblet height the riblet surface acts as a uniform roughness and a value for the equivalent sand-grain roughness height is given. Examples of the estimated drag reductions which might be achieved for two current aircraft by incorporating riblet surfaces are presented.

Descriptors :   *DRAG REDUCTION, *TURBULENT BOUNDARY LAYER, AIRCRAFT, ESTIMATES, PENALTIES, PROFILES, REYNOLDS NUMBER, SURFACE ROUGHNESS, SKIN FRICTION, TURBULENT FLOW, VELOCITY, RIBS, GREAT BRITAIN

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE