Accession Number : ADA134213

Title :   Interactions of Airfoils with Gusts and Concentrated Vortices in Unsteady Transonic Flow,

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

Personal Author(s) : McCroskey,W J ; Goorjian,P M

PDF Url : ADA134213

Report Date : Jan 1983

Pagination or Media Count : 23

Abstract : Unsteady interactions of concentrated vortices and distributed free-stream gusts with a stationary airfoil have been analyzed in two-dimensional transonic flow. A simple method of introducing such disturbances has been implemented numerically in the well-known transonic small-disturbance code LTRAN2, and calculations have been performed for two important classes of current aerodynamic problems. The first, which demonstrates many of the essential features of the interactions between helicopter rotor blades and their trailing-vortex wakes, is that of a discrete potential vortex convecting past an airfoil. The second is the response of a transonic airfoil to a transverse periodic gust, with and without the alleviation that can be achieved by the proper active control motion of a trailing-edge flap. In both cases, unsteady effects are found to play important roles in the shock-wave motion, in the overall flow-field development, and consequently, in the air loads on the airfoil. (Author)

Descriptors :   *Transonic airfoils, *Gust loads, *Vortices, *Unsteady flow, Gusts, Transonic flow, Flow fields, Free stream, Rotor blades(Rotary Wings), Aerodynamic loading, Interactions, Trailing edges

Subject Categories : Aircraft
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE