Analysis of the aeroacoustics of an ascending rocket at lift-off through high-fidelity simulations

Space vehicles' launches create a complex system of acoustic waves harmfully interacting with the ground facility and the vehicle itself. Previous engineering tools are unable to reconstruct accurately the intense aeroacoustic loads during the initial moments of a launch. Thus, it is crucial to devise innovative computational methods capable of capturing the impulsive flow resulting from the ignition of the rocket engines. In this study, we use high-fidelity, 3D large eddy simulations to simulate the flow field generated by the launch of a realistic space launcher. Our high-order, GPU-accelerated, compressible flow solver makes it possible to represent the highly turbulent interaction of the exhaust plume from the rocket's nozzle in a realistic environment. An immersed boundary method models the geometry of the launch pad and of the ascending space launcher. Results show the solver's ability to provide improved predictions compared to actual flight data measurements, despite the challenging conditions and complex – moving – geometry involved. Additionally, wavelet analysis characterizes effectively the hazardous ignition/duct overpressure mechanisms occurring during the lift-off.