Performance Analysis of Shock-Induced Pressure-CoupledCombustion in a confined chamber

Rotating detonation engines, due to utilizing pressure gained combustion wave, are capable of reaching higher efficiency in comparison with ordinary engines. In this research, structure of a combustion induced moving supersonic shock wave in an annular channel possessing a length-to-diameter ratio (l/d) of 1.3 is investigated numerically using FLUENT software. Furthermore, feasibility study for a laboratoryexclusively devoted to studying rotating detonation engines (RDEs) has been performed during which due to the high sensitivity of the formation and stability of the rotating detonation waves to mass flow rate and fuel and oxidizer injection pressures, a completely automated system has been designed to handle the difficulties encountered in feeding system. Considering negligible variations of thermodynamic parameters in radial direction, a 2-D model was employed to reduce computational costs, results of which were verifiedwith those of the experiments. Obtained results suggest that when a detonation shock wave propagates into an entrained mixture of reactants or inert gas (exhausts from previous cycle), an oblique shock wave forms above the detonation wave to regulate the pressure behind the detonation wave and the inert gas region, which itself leads to formation of a detonation-shock wave structure. Maximum speed of the detonation waves and maximum pressure behind them can be achieved using stoichiometric mixtures. Furthermore,increasing channel length at low and high injection pressures would lead to an increase and decrease of the detonation front height, respectively.

Keywords:

Detonation Wave Structure , Detonation Combustion Wave , Detonation Combustion Modeling , 2D Simulation of Detonation Waves