Influence of T-128 wind tunnel perforated walls on aerodynamic characteristics of reentry vehicles at transonic speed

The paper is devoted to the study of the influence of wind tunnel perforated walls on the aerodynamic characteristics of the reentry vehicle model at transonic speed. An experimental investigations were conducted with a model at zero angle of attack in the T-128 TsAGI transonic wind tunnel within the range of Mach numbers M = 0.9–1.1 at three perforation ratios of test section walls F = 2; 6; 10%. Aerodynamic forces and moments acting on the model were measured with a six-component internal strain-gauge balance. A distribution of static pressure on the model surface and on the test section perforated walls was measured along with static pressure fluctuations. Integral parameters of the boundary layer on the perforated wall were measured by means of the rake with total pressure probes. Numerical investigations of the flow around the model in the test section were performed by solving Reynolds Averaged Navier–Stocks (RANS) equations using the Electronic Wind Tunnel software (EWT-TsAGI). Satisfactory agreement was obtained between the computational and experimental data on the effect of the test section perforated walls on the aerodynamic characteristics of the model and the flow parameters on the wall. The influence of the perforation coefficient on the model drag coefficient in the calculations and in the experiment had the same trend. The maximum error of the drag coefficient at a simplified computational model is estimated to be 0.05. The highest effect of perforation on the drag coefficient of reentry vehicle is comprised if 1.05 < M < 1.1 and makes ΔCD ≈ 0.03–0.04.