基于非线性动力学的液体火箭发动机高频不稳定燃烧过程

High Frequency Combustion Instabilities inLiquid Rocket Engine Based on Nonlinear Dynamics

采用非线性动力学方法对液体火箭发动机非线性高频燃烧不稳定工作过程进行了研究。气相控制方程组用欧拉坐标系下的Navier Stokes方程组描述,液相控制方程组在Lagrangian坐标系下进行描述,气、液两相作用通过方程组的源项互相耦合。用高压蒸发理论对火箭发动机喷雾过程进行了描述。采用计算燃烧学的方法对发动机燃烧室内的湍流两相燃烧过程的稳定燃烧状态和高频不稳定燃烧现象进行了数值模拟。通过分析和讨论,得出了火箭发动机高频不稳定燃烧过程的波动过程类似于奇异吸引子的结论。

The nonlinear high frequency combustion instabili ty process in the liquid rocket engine is simulated with the method of nonlinear d ynamics. The gas controlling Navier-Stokes equations are described under the E uler coordinate. The liquid phase controlling equations are described under the Lagrangian coordinate. The two-phase interactions of the gas and liquid are cou pled through the sources of equations. The spray process in the rocket engine is described with the theory of high pressure evaporation. The two phase turbulent combustion steady process and high combustion instability in the liquid rocket engine are simulated with the method of computational combustion dynamics. The c onclusion is drawn that the high frequency combustion instability in the liquid rocket engine is similar to the strange attractor which looks like Lorenz attrac tor.