论文部分内容阅读
为实现对突扩燃烧室低频燃烧不稳定的高效控制,采用实验手段和数值模拟开展了低频燃烧不稳定的控制方法研究。开展了燃料脉冲喷射开环主动控制实验研究,发现燃料脉冲喷射所形成的周期性放热是抑制压强振动的主要原因。这种周期性放热与压强振动反相时会明显削弱压强振荡幅度,所以喷射相位角是影响控制效果的主要因素。对空气喷射控制方式进行了大涡模拟,这种方式能够比较有效地干扰突扩面上大尺度旋涡的形成,起到较好的抑制效果。对燃烧室突扩构型进行改进,开展了被动控制的数值模拟,通过采用台阶突扩面的被动控制方式指出了破坏大尺度旋涡的形成和切断振动能量的正反馈机制是实现燃烧不稳定被动控制的主要途径。
In order to realize the high-efficiency control of the low-frequency combustion instability combustion chamber, the control method of low-frequency combustion instability was studied by means of experiment and numerical simulation. The experimental research on active control of open-loop fuel injection is carried out. It is found that the periodic exothermic heat generated by fuel pulse injection is the main reason to suppress the pressure vibration. This periodic exotherm and pressure vibration reverse phase will significantly weaken the pressure oscillation amplitude, so the injection phase angle is the main factor affecting the control effect. Large-eddy simulation of the air injection control method can effectively disturb the formation of large-scale vortex on the sudden expansion surface, and thus has better suppression effect. The sudden expansion configuration of the combustion chamber was improved, and the numerical simulation of passive control was carried out. The passive feedback control method of stepped sudden expansion surface was used to point out the positive feedback mechanism to destroy the large-scale vortex and to cut off the vibration energy. The main control.