Experimental investigation of the transonic flow past a sounding rocket
Pedro Geovanny Martinez Romero1; Ana Cristina Avelar2; João Batista Pessoa Falcão Filho2; Edson Basso2
1 Instituto Tecnológico de Aeronáutica; 2 Instituto de Aeronáutica e Espaço
doi:10.20906/CPS/COB-2015-2392
Resumo
Numerical and experimental investigations of the flow field around a sounding rocket are carried out in the transonic regime. The study was conducted for two different nose-cone configurations, the first with a back step after the frustum cone and the second without the back step. The experiments are being conducted in the Pilot Transonic wind tunnel of the Instituto de Aeronáutica e Espaço (IAE), TTP. This facility allows aerodynamic tests in Mach number varying from 0.2 to 1.3 with automatic controls of pressure (from 0.5 bar to 1.2 bar), temperature and humidity. The flow in its test section of 0.25 m x 0.30 m is continuously driven by a main two-stage axial compressor of 830 kW on a scaled model 1:34 of the VS-40 sounding rocket model in the transonic regime. The results are obtained using the experimental the experimental techniques of Pressure Sensitive Paint (PSP) and the internal balance. Drag coefficients measured with an internal balance will be presented for several values of Mach number, and pressure fields are obtained as well using the PSP technique. Additionally, a numerical analysis was carried out to compare the results obtained with the PSP technique. It was possible to obtain the sounding rocket VS-40 Cd x Maxh number curve for the two different configurations of the nose-cone. Reynolds number effects in the flow field over the model and consequently in the drag of the vehicle is also investigated in an attempt to predict the physical phenomena occurring in a flight condition. The motivation is that the Reynolds number of flight of a real space vehicle is very high. Consequently, the laminar to turbulent boundary layer transition occurs very soon, still in the beginning of fore-body section. On the other hand, in wind tunnel tests, the flow is expected to be mostly laminar over a great extension of the scaled model. So, in order to analyze the Reynolds effects, transition strip will be used to accelerate the laminar to turbulent boundary layer transition, simulating in this way a full Reynold
Palavras-chave: Sounding vehicle; Transonic wind tunnel; Experimental methods