Wind tunnel tests for separation dynamics modeling of a two - Stage hypersonic vehicle

This paper presents results from a joint research program conducted by the Institutes of Fluid Dynamics and of Flight Mechanics and Flight Control of the Technische Universitat Miinchen on the stage separation problem of two-stage space transportation systems (TSTO). Experimental aerodynamic data are presented aimed at developing a flight mechanics model to realistically simulate the separation manuever dynamics. The investigations were conducted using the ELAC1C/EOS configuration. The tests are performed in the T-313 wind tunnel of the Institute of Theoretical and Applied Mechanics (ITAM) of the Russian Academy of Sciences, Siberian Branch, Novosibrisk. Models of 1/150-scale are tested at a freestream Mach number of 4 varying both the angle of attack of the entire configuration and the angles of incidence, sideslip and bank of the orbital stage (EOS) relative to the lower stage (ELAC1C) at specific distances between the stages. The results obtained include forces and moments for both stages as well as Schlieren pictures to determine the associated dominant flow phenomena. The data reveal that beside the pure longitudinal motion characterisctics interference effects due to small sideslip and bank angles are of concern.