触发激励下固体火箭发动机声腔特性实验

In order to study the influence of external excitation on the stability of solid rocket motor,an experimental model system for the acoustic property of solid rocket motor is built,and the axial and radial excitation experiments of solid rocket motor are carried out. The influences of throttle aperture and trigger mode on the experimental results are studied. The natural frequency and attenuation coefficient of each order oscillation are obtained. The acoustic speed in the combustion chamber measured by cross-correlation analysis is 604. 2 m/ s,and the frequency error predicated upon the measured acoustic speed is 10. 1%. The oscillation of the system can be divided into two stages according to the attenuation speed. When the throttling aperture increases,the frequency of pressure oscillation input into the motor by a pulser and the oscillation amplitude of each mode increase,and the first-stage attenuation becomes faster, while the second-stage attenuation becomes slower. The oscillation attenuation of the axial excitation is faster than that of the radial excitation on the combustion chamber head in the first stage,and it has stronger nonlinear characteristics.