Experimental study of the thermal erosion in a subscale solid-propellant launcher

A one-sixteenth subscale solid-propellant launcher has been tested to closely simulate the highly transient pressure and the material erosion characteristics of the prototype vertical launching system (VLS). The highly transient pressure responses measured in the rocket motor were verified by the lumped-parameter approach using the fourth-order Runge-Kutta method. The transient pressure responses in other components of the launcher were similar to the behavior of the rocket motor. The two-hole and four*hole nozzles, which simulated a cluster of nozzles in the prototype VLS, were separately tested to investigate the pressure responses and material erosion affected by the nozzle configuration. A small total throat area of the nozzle resulted in a shorter firing duration and higher mass efflux issuing from the rocket motor into the plenum chamber. The erosion depth contour of an ablative material repeatedly tested indicated that the charred material with previous eroded surface contour could provide better insulation than the flat surface of a virgin material. The erosion of the ablative material mainly depends on the mass efflux from the nozzle and the structure of the ablative material.