Research On Influences Of Inlet Distortion And Fuel InjectionPulse On Combustor Combustion Flow Field

Since the combustion stability of combustor directly affect the safety of the aeroengine, it isnecessary to study and analyze the combustion instability of the combustor. The combustor inletdistortion and the fuel injection pulse are important factors affecting the combustion stability. Theinfluences of the combustor inlet distortions and the fuel injection pulse on the combustor temperaturefield are studied by using numerical simulation.Nine kinds of radial distortions and two kinds of circumferential distortions are simulated byusing the flashboard. The influences of the combustor radial distortions and circumferentialdistortions on the combustor temperature field are studied by using FLUENT software. Numericalresults show that the combustor inlet velocity distortions have less influences on the temperature fieldof the combustor header.The combustor inlet velocity distortions have bigger influences on the exittemperature field. The combustor inlet velocity distortions worsen the quality of the exit temperature,especially Radial Temperature Distribution Factor(RTDF).The approximate numerical simulations of the combustion instability caused by the fuel injectionpulse and inlet distortions are carried by adding User-defined functions(udf) into FLUENT softwareto take the fuel injection pulse and inlet distortions into account. The shape of the fuel injection pulseis triangle waves. The influences of the combustor inlet distortions and the fuel injection pulse on thecombustor temperature field are studied by simulating on five different models. Numerical resultsshow that：(1)The outlet average temperature，the outlet maximum temperature and the outletmaximum average radial temperature change with the variation of the fuel injection pulse. Ahysteresis phenomenon during the transient simulation exists at the outlet average temperature，theoutlet maximum temperature and the outlet maximum average radial temperature in relation to thefuel injection pulse.(2)The fuel injection pulse severely worsen the temperature field of the primaryhole plane. The fuel injection pulse reduces the maximum temperature of the primary hole plane, andit causes the temperature distribution of the primary hole plane unideal.(3)The fuel injection pulse andthe combustor inlet velocity distortions severely worsen the quality of the exit temperature, and causethe high-temperature zone to exist in the zone of the root of the turbine blades and the tip of theturbine blades, and which has severely influences on turbine.The study results provide a support for the study of the combustion instability of the combustor.