Accession Number : ADA182326

Title :   Numerical Simulations of Unsteady Airfoil - Vortex Interactions,

Corporate Author : NATIONAL AERONUATICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCH CENTER

Personal Author(s) : Srinivasan,G. R. ; McCroskey,W. J.

Report Date : 1987

Pagination or Media Count : 23

Abstract : Unsteady interactions of a moving vortex with a stationary airfoil have been calculated using three different numerical methods based on the thin layer Navier-Stokes, Euler and transonic small-disturbance (TSD) equations. All three methods use a perturbation-form of an implicit numerical algorithm. Results are presented for both subsonic and transonic flow conditions and for weak and strong interactions. Results from these methods and from the other available numerical methods show qualitatively similar behavior for weak interactions. However, the stronger interactions considered proved to be beyond the capabilities of the transonic small-disturbance codes. In general, the results show a tremendous influence of the vortex on the flow field around the airfoil. The most dramatic results of the interaction seem to occur when the convecting vortex is within one chord of the airfoil. Even the weak interactions produced vortex/shock induced boundary-layer separation.

Descriptors :   *NUMERICAL METHODS AND PROCEDURES, *TRANSONIC FLOW, *VORTICES, AIRFOILS, FLOW FIELDS, ALGORITHMS, NUMERICAL ANALYSIS, SUBSONIC FLOW, INTERACTIONS, LOW STRENGTH, EQUATIONS, MOTION, STATIONARY, LAYERS, NAVIER STOKES EQUATIONS, THINNESS, PERTURBATIONS, CONVECTION, FLOW SEPARATION, SHOCK WAVES, BOUNDARY LAYER FLOW, ADAPTIVE SYSTEMS, UNSTEADY FLOW, REPRINTS

Subject Categories : Fluid Mechanics
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE