Interaction of a lateral jet with the projectile external flow

Abstract

Some flying vehicles are equipped with lateral jet systems to produce lateral forces and moments on the body in order to control and change its flight trajectory during the flight cycle. The application of this technology to projectiles flying in the low atmosphere is studied at ISL in close cooperation with TZN. Experimental investigations concerning the interaction between a lateral hot jet and the external flow of an axisymmetric projectile are carried out in the ISL shock tube. Interferogram pictures of the flow field near the lateral jet are taken at small angles of attack. A jet perpendicular to the body axis and a forward tilted jet are studied. The flow conditions of a projectile flying at a Mach number of about 4.5 at ground level conditions and at altitude conditions of about 7 km are reproduced in the shock tube. Numerical investigations are performed for a cold and a hot jet in order to predict their efficiency. The steady-state flow field around the jet-controlled projectile is computed by means of a 3D compressible turbulent code. This code is founded on Reynolds averaged Navier-Stokes equations closed by the k-s turbulence model. The boundary conditions of the upstream flow are similar to those of the shock tube. Those of the jet flow are imposed from numerical simulations performed by TZN. The results show a satisfactory agreement between the experiment and the numerical simulations. CDO Cp n D h H KF KM k Mf Mi Mj P Pfi Pr, 9} RP,