Windtunnel investigation of the development of the vortex wake behind a sweptback wing: part I: text and tables

Abstract

The deformation of the vortex sheet "behind a 30 sweptback wing (span 1.5 m, chord 0.3 m) has heen measured in the LST 3x2. Three types of measurements have been applied: - a total head survey (viscous wake) - yaw measurements (sidewash variation across vortex sheet) - vortex indicator measurements (vortex wake). Only a part (60%) of the total circulation is found in the tip vortex and the remainder leaves the trailing edge in the form of a vortex sheet, which deforms and diffuses downstream, but is not incorporated into the tip vortex. The viscous flow at the trailing edge of a wing does not follow the "Mangler criteria" of the potential flow (direction of the vortex sheet at the trailing edge).