Accession Number : AD0248342

Title :   A METHOD FOR THE PREDICTION OF THE ONSET OF BUFFETING AND OTHER SEPARATION EFFECTS FROM WIND TUNNEL TESTS ON RIGID MODELS

Corporate Author : ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE)

Personal Author(s) : PEARCEY, H.H.

Report Date : OCT 1958

Pagination or Media Count : 1

Abstract : The method is based on the observation of the divergence that occurs in the variation of mean static pressure at the trailing edge of an aircraft wing at the critical stage in the develop(over) ment of boundary-layer separation when its influence first spreads to the trailing edge and thereby to the over-all flow. The significance of the trailing-edge pressure variations and their connection with the effects that separation has on the mean and unsteady loads is discussed for various types of separation. Good prediction can be obtained from wind-tunnel tests, or warning provided in flight, for low-speed separations and for shock-induced ones up to the stage at which the shock wave reaches the trailing edge. Related divergences in wake width, lift coefficient, or shock position can also be used. Pressure measurements at other isolated points often indicate the type of separation. Certain special considerations apply for swept wings. The various flow changes considered are illustrated by schlieren photographs. (Author)

Descriptors :   *AERODYNAMIC CHARACTERISTICS, *AIRFOILS, *CONTROL SURFACES, *SWEPTBACK WINGS, *WINGS, AIRCRAFT, BOUNDARY LAYER, LIFT, MACH NUMBER, PRESSURE, SHOCK WAVES.

Distribution Statement : APPROVED FOR PUBLIC RELEASE