Numerical investigation of exhaust flows for missile launching in an irregular section concentric canister launcher

Flow characteristics and behaviors of the rocket exhaust plumes in the round-outside and square-inside section were simulated, in order to meet requirements of concentric canister launch(CCL)system for some special missiles with irregular section or folding rudders/wings. First, a three-dimensional numerical model of Navier-Stokes equation for compressible gas was established based on basic features of the exhaust gas discharging from the canister. Then some calculations and analyses, involving typical flow phenomena, interference effects and influence factors of the discharge gap, were performed for traditional CCL with a double-layer cylinder structure. Last, typical phenomena of the exhaust plume discharging from an irregular section CCL were researched. Results show that the discharge gap plays an important role on behaviors of the exhaust plume flow. Internal pressure of the CCL increases with the decrease of the discharge gap. The CCL with round-outside and square-inside section has a smaller equivalent area, due to changing the discharge condition of the exhaust gases, than a double-layer traditional CCL system.