关键词: 固体火箭发动机, 拉瓦尔喷管, 气-固两相流, PIV技术, 高速复杂流场

Abstract: To investigate the velocity distribution in the two-phase flow field of the solid rocket motor nozzle, a two-dimensional pla-nar visual nozzle was designed, and an online system for measuring velocity of the nozzle flow field was established. The hot firing test was carried out using a low combustion temperature solid propellant containing alumina particles. The flow field velocity in the expansion section inside the nozzle was obtained by the Particle-image velocimetry (PIV). The influ-ence of the truncated length of the side cover and shape of the visual nozzle on the two-phase flow field is studied by numerical simulation method. The experiment research results show that the maximum axial velocity is 1850 m/s, and a mixture of soot and aluminum oxide particles in the flow field. As the concentration of soot increases along the longitudi-nal direction, the gray level of the image in the flow field changes from bright to dark. By reducing the truncated length of the side cover plate of the visual nozzle, the truncated position is farther away from the nozzle throat, the diffusion angle of particles is decreased from 24.3° to 21.5°, and the particle trajectory is more concentrated on the straight wall line. The shape will affect the flow of particles in Laval nozzle. At the convergent section throat position of single-sided square noz-zle, the particles will repeatedly collide with the wall due to the constraint of the straight wall, forming a phenomenon of "staying" in the throat area temporarily. After changing the nozzle shape from single-sided square to full-size square, the maximum lag value between particles-gas velocity is decreased by 46.9%.

Key words: solid rocket motor, Laval nozzle, gas-solid two-phase flow, PIV technology, high-speed complex flow field