Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 54 9 2022 11 22 Numerical Simulation of Aero-Acoustic Noise from Supersonic Jet Reflection Using Computational Fluid Dynamics/Boundary Element Method Numerical Simulation of Aero-Acoustic Noise from Supersonic Jet Reflection Using Computational Fluid Dynamics/Boundary Element Method 2061 2084 4943 10.22060/mej.2022.21230.7406 FA Maryam Babaei Dooki MSc, Aerospace Engineering, Malek Ashtar University of Technologyو ،ثاقشدو ]قشد Hamid Parhizkar Sajjad Ghasemlooy Assistant Professor, Faculty of Aerospace Engineering, Malek Ashtar University of Technology, Tehran, Iran Journal Article 2022 03 17 Calculating acoustic loads due to the flow field produced by the outlet flow of launch vehicles impinging on the launch pad is one of the main challenges in the space industry. The sound level of outlet flow from the engine and reflection of produced acoustic waves from the launch pad and their effect on payloads depends on the turbulence parameters, created vortices, nozzle geometry, and launch pad geometry. The present paper aims to calculate the sound level generated by supersonic flow at the outlet of the launch vehicle engine besides the sound reflection from the flow deflector below the engine using a hybrid computational fluid dynamics/ boundary element method. For this purpose, the sound produced by the nozzle outlet flow in the supersonic engine of a launch vehicle is studied. In order to observe the effect of the reflection of acoustic waves from the launch pad, results are compared between two cases (with a flow deflector and without it). Numerical simulation is performed for the three-dimensional viscous compressible turbulent flow, and the boundary element method is used to compute the propagation and reflection of acoustic waves. Obtained results indicate that the generated noise level impressively increases when considering acoustic wave reflection from the deflector. The noise level generated by the projectile engine in the presence of a jet flow deflector is higher by about 8-10 dB than in the absence of a deflector. Also, results show that the acoustic waves over the projectile become more uniform by using a deflector. Calculating acoustic loads due to the flow field produced by the outlet flow of launch vehicles impinging on the launch pad is one of the main challenges in the space industry. The sound level of outlet flow from the engine and reflection of produced acoustic waves from the launch pad and their effect on payloads depends on the turbulence parameters, created vortices, nozzle geometry, and launch pad geometry. The present paper aims to calculate the sound level generated by supersonic flow at the outlet of the launch vehicle engine besides the sound reflection from the flow deflector below the engine using a hybrid computational fluid dynamics/ boundary element method. For this purpose, the sound produced by the nozzle outlet flow in the supersonic engine of a launch vehicle is studied. In order to observe the effect of the reflection of acoustic waves from the launch pad, results are compared between two cases (with a flow deflector and without it). Numerical simulation is performed for the three-dimensional viscous compressible turbulent flow, and the boundary element method is used to compute the propagation and reflection of acoustic waves. Obtained results indicate that the generated noise level impressively increases when considering acoustic wave reflection from the deflector. The noise level generated by the projectile engine in the presence of a jet flow deflector is higher by about 8-10 dB than in the absence of a deflector. Also, results show that the acoustic waves over the projectile become more uniform by using a deflector. https://mej.aut.ac.ir/article_4943_3fc0a5dc1f5757c71b88be8adbfd10e9.pdf