Influence of cold launch bullet body deflection on the force and thermal environment of launch vehicles

In response to the complex and harsh force-thermal environment of the vehicle-mounted launch system during the cold launch projectile deviation at different angles, numerical simulation study was conducted based on nested grid technology, by utilizing the Navier-Stokes component transport equations and RNG k-ε model to establish a dynamic flight gas jet model after the ignition of the projectile. Firstly, the accuracy of the calculation method was verified by comparing it with relevant experimental results. Based on this, a comparative analysis was conducted on the gas jet flow field results, the temperature and pressure distributions on the surface of vehicle components, and numerical curves at monitoring points to explore the influence of projectile deflection on the force-thermal environment of the launch system. The research demonstrated that as the inclination angle of the projectile increased, the ejection phenomenon at the muzzle of the launch tube became more pronounced. The high-temperature and high-pressure region on the surface of vehicle components moved from the middle section of the components towards the rear of the vehicle and then continued to move towards the front. The temperature and pressure peak values on the rear wall surface of the chassis and undercarriage components initially increased and then decreased. In contrast, the peak value on the middle wall surface continued to grow. With changes in the inclination angle, the temperature peak value at the mouth of the launch tube increased by up to 20%, and the pressure peak value increased by up to 450%. Meanwhile, the temperature and pressure peak values of the chassis, undercarriage, and other components increased by approximately 50%.