Wind tunnel measurements of the surface pressure fluctuations on the new VEGA-C space launcher

Abstract

An extensive wind tunnel test campaign devoted to the characterization of the aerodynamic and aeroacoustic behaviour of the new Space Launcher VEGA-C has been carried out in the trisonic wind tunnel available at the National Institute for Aerospace Research (INCAS) in Bucharest. The present paper summarizes the main results of the aeroacoustic investigation with a specific focus on the buffeting analysis. For this reason, the results presented herein are limited to the transonic conditions which are the most critical in terms of occurrence of flow instabilities. The scaled instrumented model of the VEGA-C launcher has been equipped with flush mounted Kulite sensors that provided the distribution of the wall pressure fluctuations. Pressure measurements at the wall of the wind tunnel have been carried out as well, with the scope of measuring reference signals to be used for cleaning the model pressure data from the background noise. Numerical simulations have been also performed to facilitate the physical interpretation of the experimental outcomes by qualitatively identifying the position of the shockwaves and tracking their evolution along the launcher for increasing Mach number. Data processing provides temporal statistics of the wall pressure signals as well as spectral quantities that give clear indications about the absence of buffeting.