Accession Number : AD0775072

Title :   The Flow Over a Porous Body: A Singular Perturbation Problem with Two Parameters,


Personal Author(s) : Gersten,K. ; Gross,J. F.

Report Date : MAY 1973

Pagination or Media Count : 46

Abstract : The proper design of high-speed aircraft depends to a large extent on the ability to predict the skin-friction and heat-transfer characteristics resulting from the interaction of the surface of the aircraft with the surrounding medium. At high speeds, viscous heating in the laminar boundary layer on the surface of the vehicle can cause elevated temperatures that result in loss of structural integrity or ablation of the surface. To alleviate this problem, a coolant can be injected through pores in the surface. Surface heating is reduced both by the action of the coolant and by the diminished heat transfer resulting from an increase in boundary-layer thickness. The report discusses the effects of injection or suction of material near the stagnation point of a porous body--the extreme forward point where the oncoming air is brought to rest and the boundary layer essentially begins. Emphasis is given to strong injection and suction problems.

Descriptors :   *Airframes, *Aerodynamics, *Porous materials, Two dimensional flow, Flow fields, Navier Stokes equations, Boundary layer, Stagnation point, Cooling

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE