Study On Combustion And Heat Transfer Characteristics Of The Rotating Detonation Engine

As a new type of power plant,rotation detonation engine(RDE)has many advantages such as simple structure,high combustion efficiency and high working frequency.But the work process involves very complicated flow,combustion and heat transfer processes.Under this background,this dissertation takes gas-phase rotation detonation engine as the research object and hydrogen/air as reactants,and studies the combustion and heat transfer characteristics of the rotation detonation engine combustor.In this paper,a three-dimensional premixed injection engine model was established,and the multi-step elementary reaction was used to simulate the flow field in RDE.The structure of the flow field in the combustion chamber of a rotation detonation engine is analyzed.On this basis,the effect of equivalence ratio and injection pressure on the flow field in RDE was analyzed.The results show that the propagation velocity of detonation wave increases with the equivalence ratio and the variation of detonation wave height is small within the equivalence ratio range given in this paper.The total injection pressure has an important influence on the flow field parameters of the rotation detonation engine combustion chamber When the total injection pressure changes within the range of 2.5bar-6bar,the variation of the detonation wave height changes first and then decreases;the propagation of the detonation wave Parameters such as speed,average peak pressure and average peak temperature all increase with the increase of injection pressure.In order to obtain the distribution of gas temperature,wall temperature and heat flux,based on the existing experimental system of rotation detonation engine,combined with related measuring equipment such as thermocouple and infrared thermal imager,the heat transfer characteristics of the rotary detonation engine are unfolded the study.The experimental results show that the gas temperature tends to decrease along the axial direction under the certain equivalence ratio,but the temperature in the wall of the combustion chamber first increases and then decreases.For the same measurement point,the gas temperature and the wall temperature increase with the equivalence ratio.During engine operation,the detonation wave height is located in the combustion chamber head,resulting in the combustion chamber head wall temperature rise rate was significantly higher than the tail position,the combustion chamber wall along the axial temperature gradient,and the head to tail heat transfer.Within the operating conditions listed in the text,the average heat flux at the combustion chamber wall at the end of engine operation increases slightly with the equivalence ratio,and for a given equivalence ratio,the heat flux at the wall of the combustion chamber decreases in the axial direction.The numerical simulation of the heat flux distribution in the inner and outer wall of the rotary detonation engine was carried out.The results show that the heat flux on the outer wall of the combustion chamber is higher than the heat flux on the inner wall,and the heat flux on the wall of the combustion chamber first increases and then decreases along the axial direction.At the intersection of the rotating detonation wave and the oblique shock wave,value.The variation of the wall heat flux obtained by numerical simulation outside the rotational detonation wave in the axial direction agrees well with the experimental results.However,due to the limited spatial resolution of the experimental measurements within the height of the rotational detonation wave,the wall heat flux There is a difference between the experimental results and the experimental results.According to the heat transfer characteristics and heat flux distribution characteristics of the rotation detonation engine combustion chamber,three different cooling schemes were designed and the related numerical simulation was carried out.The advantages of the three cooling programs and the existence of defects into the phase analysis,after the cooling effect,economy and machinability of the comprehensive consideration of the cooling obtained a better solution.