Numerical simulation of an air-assisted liquid jet submitted to a high-frequency transverse acoustic modulation

International audienceThe numerical simulation of high-frequency combustion instabilities in liquid rocket engines under subcritical operating conditions is a challenging task. To simulate the mechanisms leading to the combustion of the liquid-injected oxidizer, Onera developed a numerical strategy based on the coupling between (1) a diffuse interface method for the dense phase and (2) a kineticbased Eulerian model for the dispersed phase. The present contribution evaluates the ability of this numerical methodology to reproduce interaction mechanisms between two-phase flows and acoustics that may intervene under unstable operating conditions. To do so, the numerical simulation of a non-reactive two-phase flow submitted to a transverse acoustic modulation is performed and compared to experimental observations. The flattening of the liquid core under acoustic constraint is retrieved, as well as the spray oscillations. Furthermore, it is shown that the shape changes of the liquid core directly impact the opening angle and the symmetry of the spray