Some early experiments on vortex separation

Abstract

Part I. Some Low Speed Aerodynamic Properties of Cones. The results are presented of some low-speed wind tunnel tests on a right circular cone with apex angle 20 deg. and on elliptic cones with apex angles 60 deg. and 20 deg. The experiments included balance tests, measurements of pressure distribution and a limited amount of flow visualisation with tufts. The emphasis of the work has been on the range of angles of incidence for which viscous effects were appreciable. Symmetric and asymmetric vortex arrangements were found over the suction side of the right circular cone. Part II. Some Low Speed Experiments with 20 deg. Delta Wings. The results are presented of some low speed wind tunnel tests on two delta wings with sharp leading-edges which have 80 degrees sweepback. Leading edge separation and vortex formation on the suction sides of the wings were found at angles of incidence in excess of three degrees. The experiments included balance tests, measurements of surface static pressure along seven generators and at two chord stations, the determination of contours of constant total pressure in the vortex region and some flow visualisation with tufts, smoke, oil and a paraffin and chalk mixture. Part III. Further Experiments with 20 deg. Delta Wings. The recent appearance of Mangler and Smith's theoretical analysis of the flow past slender delta wings with leading edge separation has encouraged the writer to note down the results of some experiments which are supplementary to those reported in Part II. The notation used here is that of Ref. 1. Some preliminary results of experiments with yawed delta wings are also presented.