URANS Analysis of a Launch Vehicle Aero-Acoustic Environment

Abstract

Predicting and mitigating acoustic levels become critical because of the harsh acoustic environment during space vehicle lift-off. This paper aimed to study the aero-acoustic environment during a rocket lift-off. The sound propagation within a launch event was studied using dedicated computational fluid dynamics (CFD). The resolution of all the phenomena that occur is unfeasible. We discuss the turbulence simplification and propose a feasible simulation through an unsteady Reynolds-averaged Navier–Stokes (URANS) model. The results were validated with experimental data showing a good correlation near the fairing surface and an improvable accuracy in the far field. To assess noise generation, the main shock waves were identified, and the evolution of the generated sound pressure was assessed. Moreover, vertical directivity was revealed by data analysis of the pressure field surrounding the fairing.

Acoustic Characterization of Vega Lift-off Environment via Ray Acoustics Modelling and Direct Field Acoustic Noise Testing

“…Characterizing these environments during the real launch entails a huge engineering challenge due to accessibility and cost issues. In this context, simulation models of various levels of fidelity are typically used to obtain approximations of the mechanical and acoustic loadings arising under such conditions [1]. However, simplifications and modelling assumptions always introduce a certain degree of uncertainty in the predictions made by these simulations, which explains why full-assembly dynamic environmental tests are always conducted in the space mission to validate the models and qualify the structures.…”

An extension of the all-Mach number pressure-based solution framework for numerical modelling of two-phase flows with interface

“…For the single phase modelling including multicomponent gases, a pressure-based numerical tool employing the hybrid approximation of convective fluxes [9,10] was developed earlier. The solver has been validated against different physical conditions [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] and for the wide range of Mach numbers. The next step for the framework development was the adaptation for simulation of high-speed multicomponent real-gas flows [27,28] in context of consideration of the phase separation phenomenon.…”

An Extension of the All-Mach Number Pressure-Based Solution Framework for Numerical Modelling of Two-Phase Flows with Interface

“…For the single phase modelling including multicomponent gases, a pressure-based numerical tool employing the hybrid approximation of convective fluxes 9,10 was developed earlier. The solver has been validated against different physical conditions [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] and for the wide range of Mach numbers. The next step for the framework development was the adaptation for simulation of high-speed multicomponent real-gas flows 27,28 in context of consideration of the phase separation phenomenon.…”