Wind-tunnel studies on maneuvering slender bodies

Abstract

In this paper, the rst experimental results of tests with a new model support designed for simulations of high frequency and high amplitude pitching maneuvers are presented. A generic missile model with a blunt nose was used for which static test data from earlier experiments with a conventional model support were existing. At the beginning, comparing static tests were done to judge the influence of the new set-up (model support, sting for the model, pivot arm) on the measured forces and moments. Afterwards, dynamic tests with sine oscillations at frequencies of fa = 0.05Hz...4Hz and angles of attack varying between a = 0°...45° were performed. Beside the qualication of this new test rig, the tests were used to study the "Phantom Yaw Effect" and to prove an interactive method of its control. This phenomenon is characterized by unwanted yawing moments resulting from asymmetric vortices which can occur on slender bodies at high angles of attack. In the tests, a leevortex control device with symmetrically arranged longitudinal slot nozzles producing "air-jet strakes" was demonstrated to decrease the yawing moments both under static and dynamic conditions.