非线性高频振荡燃烧的研究

Study on Nonlinear High Frequency Acoustic Oscillation Combustion

用数值模拟的方法研究了液体火箭发动机高频振荡燃烧的形成和发展过程。气相控制方程用欧拉坐标系下的Navier－Stokes方程组描述，液相控制方程在Lagrangian坐标系下描述，并采用高压蒸发燃烧模型。从计算的结果可以看出，当燃烧室内发生高频振荡燃烧时，在喷注面附近和燃烧室收敛段这两个区域内压力的波动幅度较大；通过对压力、混合气体温度及速度在振荡燃烧情况下的比较，得出了振荡燃烧发生时发动机内部两相流场的脉动频率与燃烧室固有频率相耦合的结论。

The forming and developing processes of high frequency acoustic combustion are studied with the method of computational modeling in this paper. The gas governing equations are described under the Euler coordinate, and the liquid phase governing equations are described under theLagrangian coordinate. The high pressure combustion model is adopted. It is observed that the pressure oscillations near chamber head and convergence is greater than others when there is high frequency combustion instability in the chamber. After comparing the pressure, the temperature and velocityof the mixed gas under the condition of unstable combustion, the conclusion is drawn that the oscillation frequencies in two phase flow and combustor are the same when acoustic combustion occurs.