EXPERIMENTAL AND NUMERICAL ANALYSIS OF THE TRANSONIC VORTICAL FLOW OVER A GENERIC LAMBDA WING CONFIGURATION (Chapter 6)

Abstract

In this chapter, an analysis of the flow physics at transonic speed is presented for the generic UCAV configuration SACCON. This configuration is characterized by a leading edge whose geometry varies in span-wise direction. Several experimental and numerical investigations have already been conducted within the subsonic speed range with a wind tunnel model that has been downscaled by 1:8 with respect to the original configuration. However, most of the time real configurations operate at transonic velocities. Therefore, it is important to analyze and understand also flow phenomena and the aerodynamic characteristics at transonic speeds. In this chapter, experimental surface oil flow images and Schlieren images are used to compare the experimentally determined flow topology with topologies obtained numerically using different turbulence models. In the first part of the chapter, numerical results are validated based on experimental results. Thereafter, a detailed interpretation of the flow is presented. Based on numerical results the flow physics at low and high transonic speeds is illustrated for medium and high angles of attack. A result of the particular SACCON design is a vortex dominated flowfield with shock vortex interaction. The subsequent analysis contributes to an understanding of the flow physics of the non-slender flying wing configuration SACCON.