Acoustic numerical simulation of high frequency combustion instability

High frequency combustion instability is one of the major issues existed in design process of liquid rocket engine. A time domain numerical simulation was used to predict high frequency combustion instability of hypergolic propellant orbit maneuvering engine (OME) by computational aeroacoustics, which was less dispersive and dissipative. The coupling between unsteady heat release and acoustics was realized by Crocco's pressure time lag model. The effects of different parameters of pressure time lag model on stability were analyzed, and the stability map was obtained. The first order transverse mode and the first order radial mode were recognized as the most dominant instable modes, which were consisted with the instable modes recognized from experimental results of ground test. The results show that high frequency combustion instability can be successfully predicted, when acoustic perturbation equations with Crocco's pressure time lag model are solved in the time domain by computational aeroacoustics.