Controlled Aerodynamic Loads on a Slender Axisymmetric Body at High Incidence

摘要

The flow over an inclined slender axisymmetric cylinder (L/D = 11) with an ogive forebody is investigated experimentally at high angles of attack up to a = 65°. Of particular interest is the evolution and control of net side forces that are associated with asymmetries of the forebody vortices. It is shown that the interactions of the forebody vortices with the near-wake vortices of the cylinder leads to the formation of a vertical stack of counter-rotating streamwise vortices whose order depends on the dominant asymmetry of the forebody vortex pair. Synthetic jet actuation applied at the juncture of the forebody leads reversal of the order of the vortex stack in the wake and consequently alters the net side force. The present investigations also demonstrated that unsteady coupling between the cylindrical body and its near wake can lead to strong yaw-roll instabilities. The manipulation of the body vortex system and the side force by flow control actuation can be used for bi-directional control of the body's trajectory and suppress this instability.