Experimental characterisation of lateral thrust jets for subsonic missile configurations

Abstract

The LK6E2 is designed by DLR as a missile against ground or low flying targets. It operates at low altitude and high subsonic velocities. The missile is boosted by four lateral thrust nozzles at its tail while aerodynamic forces and moments are generated via four main and four rear wings (fins). The aim of the current study is to assess experimentally a potential interaction of the thrust jets on the control surfaces. As this problem cannot be directly assessed, a stepwise approach is used: Based on similarity rules, a cold gas model is designed and investigated with Pressure Sensitive Paint (PSP) and Particle Image velocimetry (PIV) first. Then, same rules are applied to design a hot gas model to be used with a solid propellant suitable for wind tunnel experiments. Hot gas PIV is applied and results are compared with the cold gas case. Additionally, flow visualisation is performed by means of Schlieren imaging. Finally, a combined analysis of all experimental results should allow for a transfer of the findings to the real configuration, but this is a future step and not yet addressed herein.