| Rotating detonation combustor supersedes traditional gas turbine engine combustor,and realizes the engine from pressure cycle to detonation cycle,which can significantly improve the thrust performance of engine and fuel efficiency.Therefore,related topics about RDC applying to gas turbine engines and their application in engineering have drawn wide attention from research institutes.In this paper,the characteristics of the outlet flow field of the rotating detonation chamber and the matching characteristics of the turbine are studied by numerical simulation and experiment.The main conclusions are as follows:(1)Based on two-dimensional compressible Euler equations,the rotating detonation outlet flow field with hydrogen-air mixture is investigated numerically.The characteristics of the outlet total pressure and outlet total temperature of the combustion chamber under the conditions of single double and triple wave mode,the axial length of different combustion chamber and the length of the circumferential direction and the total pressure of different injection and different back pressure are compared and analyzed.Through studying the total pressure pulsation,aberration index and outlet temperature distribution factor in the combustion chamber,the uniformity of the outlet flow field of the combustion chamber is analyzed.Research results show that combustion outlet average total pressure fluctuation value in triple wave mode is smaller than that in the single and double mode wave,and the uniformity of flow field is higher.Equivalence ratio has great influence on the outlet temperature distribution factor of combustion chamber.With the increase of equivalence ratio,the outlet temperature distribution factor increases first and then decreases.In addition,the more the number of waves are,the smaller the outlet temperature distribution factor is,and the uniformity of flow field is higher.Equivalence ratio has a certain influence on the pressure ratio of combustion chamber but not significance.Furthermore,the number of waves is inversely correlated with the pressure ratio.The size of combustor has great influence on the non-uniformity of the flow field.With the increase of the axial length of chamber or the decrease of the circumferential dimension,the average of outlet total pressure fluctuation,the distortion index and outlet temperature distribution factor will be decreased,and the uniformity of the outlet flow field is increased.The pressure conditions have some influence on the flow field at the outlet of the combustor.With the increase of the total pressure,the average pulse pressure,the distortion index and outlet temperature distribution factor increase gradually and the uniformity of the flow field becomes worse.(2)Based on the combination of rotating detonation combustion chamber and turbine guide device,the detonation experiments were carried out,and the rotating detonation wave was successfully initiated.The experimental results of the combined guide and not installed guide are analyzed.Experimental results show that under the condition of two kinds of working condition,the propagation velocity of the rotating detonation wave increases first and then decreases with the increasing of equivalent ratio.However,after adding the guide,the relative deviation of the detonation wave propagation velocity decreases first and then increases,and the range of its stable propagation is narrower than that without a guide device.In addition,before and after the guide,there is a consistent pressure oscillation frequency in the combustion chamber.The amplitude of the oscillating pressure is reduced by 64%after the guide.The oscillating pressure directly enters the turbine after the guide.Compared with no guide,the influence is relatively small.The guide blade has a reflection effect on the oscillation pressure in outlet of the combustion chamber,then affects the pressure of the detonation combustion chamber.The path of the reflected shock wave is related to the direction of the detonation wave propagation.The feasibility of rotating detonation combustion chamber and turbo combination scheme is further verified by further experiments of rotating detonation combustion chamber and turbine combination.The study shows that the turbine has a certain influence on airflow velocity in combustion,and the airflow velocity in combustion will be increased after adding the turbine,which affects the detonation characteristics of the engine.Turbine also has certain influence to the combustion chamber pressure,and the detonation wave will be reflected on the turbine blades.The strength of the shock wave reflection is different under different equivalent ratio.With the increase of the equivalent ratio,the detonation wave velocity and pressure increase,and the effect of blade on the strength of the shock wave reflection will be increased. |
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