This paper studies the four-engine liquid rocket flow field during the launching phase. Using three-dimensional compressible Navier-Stokes equations and two-equation realizable k-epsilon turbulence model, an impact model is established and flow fields of plume impinging on the two different shapes of flame deflectors, including wedge-shaped flame deflector and cone-shaped flame deflector, are calculated. The finite-rate chemical kinetics is used to track chemical reactions. The simulation results show that afterburning mainly occurs in the mixed layer. And the region of peak pressure occurs directly under the rocket nozzle, which is the result of the direct impact of exhaust plume. Compared with the wedge-shaped flame deflector, the cone-shaped flame deflector has great performance on guiding exhaust gas. The wedge-shaped and cone-shaped flame deflectors guide the supersonic exhaust plume away from the impingement point with two directions and circumferential direction, respectively. The maximum pressure and temperature on the wedge-shaped flame deflector surface are 37.2% and 9.9% higher than those for the cone-shaped flame deflector. The results provide engineering guidance and theoretical significance for design in flame deflector of the launch platforms.

本文研究了发射阶段的四发液体火箭流场。利用三维可压缩 Navier-Stokes 方程和两方程可实现 k-epsilon 湍流模型，建立了冲击模型和羽流撞击两种不同形状的火焰偏转器的流场，包括楔形火焰偏转器和锥形火焰偏转器。火焰偏转器，计算。有限速率化学动力学用于跟踪化学反应。模拟结果表明，后燃主要发生在混合层。而峰值压力区域出现在火箭喷嘴正下方，这是排气羽流直接冲击的结果。与楔形导火器相比，锥形导火器具有良好的废气引导性能。楔形和锥形导火器分别从两个方向和圆周方向引导超音速排气羽流远离撞击点。楔形导火器表面的最大压力和温度比锥形导火器高37.2%和9.9%。研究结果为发射平台导火器的设计提供了工程指导和理论意义。