Performance Of The Rotating Detonation Combustion Chamber And The Thermodynamic Cycle Analysis Of Gas Turbine

Because of its small size and simple structure,the rotating detonation chamber has great potential for development.However,as a new type of combustion chamber,the research of the rotating detonation chamber is just in the primary stage,related factors that effect on rotating detonation combustion chamber performance is not deep enough.Therefore,it is of great significance to further analyze the flow field structure of rotating detonation chamber and to calculate the thermodynamic cycle efficiency of rotating detonation gas turbine in order to promote the development of rotating detonation gas turbine.In order to analyze the flow field structure and determine the influence factors of the combustion chamber performance,a numerical simulation was carried out on the two dimensional circumferential surface of a rotating detonation combustor.In the process of solving the two-dimensional unsteady Euler equation,the density solver was adopted and the explicit scheme was used.The effects of viscosity,heat conduction,diffusion and other transport effects were neglected.The fuel in the combustion chamber was chosen to be the methane / air premixed gas which was in accord with the engineering practice.The specific work of this paper is as follows:First,the numerical simulation was carried out on the two dimensional circumferential expansion surface of a rotating detonation chamber,and the flow field structure of rotating detonation chamber was analyzed.There was a certain periodicity in the propagation of detonation wave,and the frequency of the rotating detonation wave was higher than that of the pulse detonation.Second,in the process of numerical simulation,the influence of boundary conditions on the performance of rotating detonation chamber was investigated.The results showed that with the inlet pressure increased,the pressure ratio of combustion chamber first increased and then decreased,and the pressure ratio was up to 2.79.The pressure ratio increased with the inlet flow temperature and combustion chamber axial length decreased.Third,the effect of equivalence ratio on the performance of the rotating detonation combustor and the lean burn off process of the rotating detonation combustor were studied.The results showed that when the equivalence ratio decreased from 1 to 0.7,the propagation velocity of the detonation wave and the pressure ratio decreased.When the equivalence ratio was 0.65,the detonation wave could only spread in the combustion chamber for a round,and then the lean burn off phenomenon occurred.When the volume ratio was 0.6,the rotating detonation could not be realized in the combustion chamber,lean burn off phenomenon directly occurred.Fourth,based on the results obtained from the numerical simulation,the performance prediction model of rotating detonation chamber was obtained.On this basis,the ideal cycle and actual cycle efficiency of the rotating detonation gas turbine were calculated,and compared with the cycle efficiency of the gas turbine based on conventional combustion chamber.The results showed that the new type of gas turbine could improve the cycle thermal efficiency.