C.H.E. Warren

In the last few years there has been a great advance in our knowledge of transonic airflow. This has been brought about experimentally through the development of the transonic wind tunnel and the ground-launched rocket-boosted model technique, and theoretically by the development of the transonic small perturbation theory. This paper reviews the results of some of the recent theoretical work, and then goes on to present some of the recent British work on the problem of shock-induced flow separation. In discussing the theoretical results particular attention is paid to the violent changes in lift and aerodynamic center position that are predicted in the transonic range. The important roles played in this connection by shock waves and sonic lines, and their movement with change in Mach number, are brought out. Violent changes in the upper transonic range are due to sonic line movements, and those in the lower transonic range to shock wave movements. Shock waves, however, nearly always cause flow separation at some stage, and thus account must be taken of the boundary layer in assessing this problem. It is with this problem that most of the recent British work has been concerned. The local Mach number and the pressure ratio that cause separation on airfoils are established, and are compared with similar results from tests on a flat-plate, and with theory. The effect of flow separation on the movement of the shock waves is discussed. Finally, the paper investigates the chances of avoiding separation by appropriate choice of planform and section.

WGL-Tagung, Duisburg, 1954

Conference Paper

englisch

21,0 x 29,7 cm, 7 Seiten

Jahrbuch der Wissenschaftlichen Gesellschaft für Luftfahrt, 1954, Band I, ; S.51-57; 1954; Braunschweig : Vieweg

NA

Bestellbar

1955