关键词: 无人机, 计算流体力学, 非定常流动, 动态嵌套网格, 导弹发射, 喷流效应, 气动干扰

Abstract: This paper simulates a missile launch process by the computational fluid dynamics (CFD) method, through which the aerodynamic interference and rules of missile movement with and without consideration of the plume field are studied. A moving chimera grid approach is used coupled with an unsteady Euler flow solver, and a 6-DOF model is fully integrated into the CFD solution procedure to capture the time-dependent interference between the stationary and moving boundaries. Two thruster models are developed to account for the influence of thruster rockets on the flowfield. One model applies an equivalent massflux at the rocket nozzle exit in order to simulate the rocket plume effects. For the second model, the thrust vector exerted by the rockets is attached to the missile body for the duration of the run. And the paper presents the results obtained for a time-accurate missile launching from the quasi-"Global Hawk" unmanned aerial vehicle (UAV) by the developed numerical methods. All major trends of the trajectory are captured, including the displacements, angular orientations, pressure coefficient distribution on the plane in the captive position, and force coefficients histories during separation, which are then used for comparison. The results show that the effect of the plume field is significant on the missile dynamic characteristics and aerodynamic interference. The simulations may provide a tool for design verification and risk mitigation for the missile launch procedure.

Key words: unmanned aerial vehicle, computational fluid dynamics, unsteady flow, moving chimera grid, missile launch, plume effect, aerodynamic interference