Investigations on the influence of one and two-sided jet deflector on acoustic environment of multi-nozzle launch vehicle at lift-off

Abstract

Abstract To study the acoustic environment of multi-jet impinging the jet deflector when the launch vehicle takes off, a compressible flow model of gas-air is established. The turbulence equation of scale-adaptive simulation (SAS) and the acoustic analogy method (FW-H) are solved numerically by using the second-order Roe scheme. The jet noise of a single rocket engine is numerically simulated. The error between numerical results and experimental data is within 3dB, and the reliability of the numerical method is verified. On this basis, the flow field and acoustic environment of the multi-nozzle launch vehicle are studied, and the effects of the jet deflector configurations on the acoustic environment of the vehicle are analyzed. The results show that, compared with the one-sided jet deflector, the two-sided jet deflector can reduce the overall sound pressure level around the vehicle by up to 6.6%. For the one-sided jet deflector, the overall sound pressure level of the receivers at the outlet of the jet deflector is larger than that of the other side. The analysis method and research results in this paper provide reference for predicting the acoustic environment of the launch vehicle and improving the acoustic environment.