The Flow Field Characteristic Of Combustor And Performance Optimization Of Continuous Rotating Detonation Engine

The influence of exhaust nozzle expansion ratio and contraction ratio to the CRDW(Continuous Rotating Detonation Wave)propagation characteristics and the engine thrust performance has been investigated by experiment and numerical simulation,in this paper.The research achievements have some guiding significance to the design of CRDE exhaust nozzle.The influence of exhaust nozzle expansion ratio and contraction ratio to the CRDW propagation characteristics and the engine thrust performance has been investigated by 3D numerical simulation of CRD with plume.The research shows the length of exhaust nozzle、the expansion angle and the back pressure have little influence to the rotating detonation structure and propagation characteristics.The expansion ratio is the key factor to determine the pressure of combustor outlet.When the pressure of combustor outlet equals to the pressure of nozzle end face,the thrust performance will be best.Increasing the expansion angle properly is good for improving the thrust performance.The engine thrust performance will improve with the reduction of the back pressure.Because the negative thrust will decrease greatly with the reduction of the back pressure.The influence of exhaust nozzle contraction ratio has been investigated by numerical simulation.The research shows that with the increase of contraction ratio,the mass flow rate will reduce,the combustor pressure will rise,the height of detonation wave will reduce and the propagation frequency of detonation wave will increase.When the contraction of exhaust nozzle is little,the engine performance will reduce compare with expand nozzle.With the increase of contraction ratio,the engine performance will improve constantly.A series of experiment has been conducted by changing experiment working condition and exhaust nozzle contraction ratio.The research shows that the propagation mode has one-wave homo-rotating mode、two-wave homo-rotating mode and two-wave hetero-rotating mode.The two-wave hetero-rotating mode is unstable and will translate into the two-wave homo-rotating mode.Increasing the equivalence ratio and mass flow rate properly is good for improving the thrust performance.The thrust performance will rise firstly and then reduce with the increase of contraction ratio.Because the top limit of contraction ratio in numerical simulation is less than experiment,the influence of contraction ratio to the thrust performance in numerical simulation can only reflect a part of experiment rule.