Spatial linear analysis of the flow in a solid rocket motor with burning walls

A theoretical investigation of the coupling between the core flow process and combustion sublayer process in a rocket chamber flow is presented. The focus of the investigation is on penetration of chamber disturbances into the sublayer and on the burn rate characteristic responses. Characteristic solutions to the local non-parallel instability problem supported by gasifying propellant in a double slab geometry are sought. In the fully decoupled limit the only characteristic solution response is a pressure response, thus comparisons between coupled and decoupled pressure responses are presented. The propellant is typified by a set of burning characteristics, and their effect on the coupling is explored. The goal of the analysis is to clarify the extent strand burning characteristics (i.e., in zero cross flow conditions) can affect burn rate perturbations leading to the phenomenon of erosive burning. The findings of this research agree with experimental studies as it regards the effect of burning parameters on erosive behavior. Change in erosive sensitivity with propellant characteristics is thus correlated with a change in the core–sublayer interaction.