Experimental investigation on secondary combustion in solid rocket ramjet

The secondary combustion of full-scale solid rocket ramjet was investigated by using the ground direct-connected experimental equipment with uncertainty evaluation. The effects of injector configuration of different gas generator, air inlet angle, dome height and length of secondary chamber on secondary combustion were determined by measuring the impulse efficiency, and their effect mechanism was analyzed. The analysis results show that the impulse efficiency of solid rocket ramjet with five injectors is higher; the inlet way of gas has an important effect on the secondary combustion in secondary chamber; the increase of inlet angle can effectively improve impulse efficiency, but intensify the deposition of combustion product in the secondary chamber; the dome height of secondary chamber should not be too big; the impulse efficiency cannot linearly increase with the dome height; the increase of secondary chamber length can improve the impulse efficiency, but the effectiveness isn't satisfactory.