실린더-3슬롯 그레인형 모터에서의 연소 불안정 발생 원인과 감쇠방안 LES

Large eddy simulation has been applied in order to analyze the flow instability caused by unsteady flow structure in solid rocket motors, Two motors of a cylinder- 3 slots type grains (one has the cylinder length same as the acoustic longitudinal node length but the other has not same) were concerned to perform quantitative comparison of oscillatory pressure amplitude and frequencies. The gain not same as the acoustic node length diminishes the pressure oscillations observed in the other case and the tangential mode is dominant one. The coherent vortex generating at the expansion area from cylinder to slot is the major source to produce the pressure oscillated continuously in the slotted region.