混合式脉冲爆震发动机噪声辐射特性研究

Research on Noise Radiation Characteristics of Hybrid Pulse Detonation Engine

对脉冲爆震燃烧室(PDC)及由压气机、PDC和涡轮组成的混合式脉冲爆震发动机(HPDE)在不同点火频率、不同当量比和充填系数下的噪声辐射特性进行了试验研究。发现两种结构的噪声峰值声压级均随爆震频率的提高变化不大,但随当量比和充填系数的上升而增大;脉冲声压级均随爆震频率、当量比和充填系数的上升而增大;HPDE比PDC的峰值声压级减小约4dB,脉冲声压级减小约2dB;HPDE的推力壁压力、管壁压力和爆震室出口峰值压力比PDC相同位置处的的压力大;在当量比不变时,随充填系数的上升,HPDE爆震室出口峰值压力经过涡轮后的衰减量减小,且充填系数越大,衰减得越小,在充填系数为1.0时可衰减29.74dB。

The noise radiation characteristics of a hybrid pulse detonation engine （HPDE） and a single pulse detonation combustor （PDC） are investigated under several operating frequencies, different equivalence ratios and fill factors. It is found that the peak sound pressure levels of HPDE and PDEC are not sensitive to operating frequencies, but the peak sound pressure levels increase with the increasing of equivalence ratios and fill factors. The impulse sound pressure levels increase with the increasing of operating frequencies, equivalence ratios and fill factors. The peak sound pressure level of HPDE is about 4dB smaller than that of PDC. The impulse sound pressure level reduces about 2dB. The head pressure, pipe pressure and PDC outlet pressure of HPDE are greater than the corresponding values of single PDC. Decay of the peak pressure at the exit of PDC of HPDE after passing the turbine decreases with the increasing of the fill factors in the case of constant equivalence ratio. The decay can reach 29.74dB when the fill factor is 1.0.