Development of a fast evaluation tool for rotating detonation combustors

Abstract

• Reduced modeling of rotating detonation combustors. • Prediction of the combustor performance in function of the inlet conditions. • Prediction of the radius to detonation height ratio for minimum entropy. Although rotating detonation engines may lead to improvements in the cycle thermal efficiency, their overall optimization is currently constrained by the need to perform time-consuming three-dimensional Navier–Stokes simulations of the combustor. Thus, there is a critical need to establish fast models to calculate the time-dependent temperature and pressure at the combustor outlet for further engine analysis and turbine integration. This manuscript describes a fast 2D simulation code of a rotating detonation combustor. This numerical methodology uses a 1D chemical kinetics solver, to reproduce the change of properties across the detonation wave front. The post-detonation flow is then resolved using a method of characteristics, which allows the prediction of pressure and temperature gain across the combustor. The main flow pattern, including the detonation front features, the shock wave angle and the outlet properties were compared with the solution of a two-dimensional Unsteady Reynolds Averaged Navier–Stokes solver. This approach is subsequently used to predict the detonation height based on the entropy generation across the combustor.