脉冲爆震涡轮发动机气动阀特性数值模拟研究

Numerical Simulation Study on Pneumatic Valve Pulse Detonation Turbine Engine

为减小脉冲爆震燃烧室爆震波压力前传,确保爆震室与压气机匹配成功,在爆震室头部设计了气动阀,并建立其数值有限元模型,研究气动阀对爆震前传压力波的详细作用和气动阀关闭时间对前传压力波衰减特性的影响。结果表明:爆震前传压力波透过气动阀在上游所形成的压缩波会扰乱气流,导致压缩波和膨胀波在压气机和气动阀之间来回震荡,不利于发动机爆震室填充;所设计的气动阀对爆震前传压力波具有很好的抑制作用,压力峰值衰减达72.9%,而无阀时压力峰值衰减仅为47.3%;气动阀对前传压力波的衰减效果随阀体关闭时间的缩短而提高,但当阀体关闭时间缩短到0ms时,其衰减效果突然下降,为69.819%。

In order to reduce the amplitude of pulse detonation wave passing back and to make sure that the match is successful between the pulse detonation combustor and the compressor , a pneumatic valve was designed at the head of the pulse detonation combustor .The numerical finite element model of the pneumatic valve was established;on this model the detailed mechanism and attenuation characteristics of the pneumatic valve on the passing -back wave were studied .The results and their analysis show preliminarily that：the passing-back wave disrupts the airflow upstream of the pneumatic valve;this disruption causes compression waves and expansion waves back and forth be-tween the compressor and the pneumatic valve , so it is not conducive to the filling up of pulse detonation combus-tor;under the effect of the valve the pressure peak attenuation is 72.9%, while it reduces to 47.3%with no valve;these percentages indicate that the pneumatic valve has good inhibition effect on the passing -back wave;the attenu-ating effect is increased with the shortening of the valve closing time , but when the valve closing time shortens to 0ms, the attenuation effect suddenly drops to 69.819%.