燃烧室压力振荡对液-液同轴离心喷嘴混合比的影响

Effect of combustion chamber pressure pulsation on mixing ratio of liquid-liquid coaxial swirl injector

基于液体喷嘴动力学理论,对燃烧室压力振荡引起同轴喷嘴混合比振荡的动态过程进行了理论分析,推导得到了混合比振荡与燃烧室压力振荡之间的传递函数。通过算例计算了液氧煤油双组元喷嘴混合比对室压振荡响应的传递函数的幅频特性。结果表明:混合比振荡幅值随着振荡频率的增加呈现先增加,后减小的趋势。传递函数值随供应系统压力的升高而增大,随喷嘴压降的升高而减小。混合比振荡最大幅值所对应的频率不随供应系统压力和喷嘴压降变化而改变,说明此频率是由双组元喷嘴的特性决定的。

Based on the theory of liquid injector dynamics,the dynamic response of coaxial injector mixing ratio to the pressure pulsation in combustion chamber was theoretically studied,and the transfer function between the mixing ratio pulsation and combustion chamber pressure pulsation was also derived.The amplitude-frequency characteristics of the transfer function were calculated with a model liquid oxygen-kerosene bipropellant injector.Results showed that as the pulsation frequency increased,the pulsation amplitude of mixing ratio increased first,then decreased.The amplitude of transfer function increased when the supply system pressure increased,and decreased when the injector pressure drop increased.The frequency corresponding to the maximum amplitude was independent of supply system pressure and injector pressure drop,meaning that this frequency was dependent on the injector characteristics.