Effects of Thrust Vectoring in Solid Rocket Motors with Submerged Nozzles

Nozzle gimbaling is used to enable thrust vectoring in solid rocket motors with submerged nozzles. This introduces three-dimensional (3D) asymmetry in the otherwise axisymmetric geometry of the solid rocket motor. A 3D, multiphase computational fluid dynamics case study on the unvectored and vectored mode of operation of the Large IUS Motor has been conducted to understand the effects of thrust vectoring. A bimodal size distribution of the condensed combustion products in the motor has been adopted. The whole motor, that is, the combustion chamber and nozzle, is simulated together to capture the effects of thrust vectoring at a system level using an in-house 3D multiphase code based on the Eulerian–Eulerian framework. Significant bidirectional azimuthal flow, along with a biased particle accumulation tendency, has been noted in the aft section of the combustion chamber when the nozzle is tilted. Slightly elevated chamber pressures have been observed in the thrust vectored state at three different burn times. The performance characteristics of the nozzle in the vectored state are improved due to the elevated chamber pressure, leading to nearly identical [Formula: see text] in the vectored and unvectored state despite the redirected thrust vector.