突扩燃烧室低频燃烧不稳定主动控制的大涡模拟仿真(英文)

Large eddy simulation of active control on low frequency combustion instabilities in a dump combustor

采用大涡模拟结合多步化学反应模型开展了突扩燃烧室低频燃烧不稳定的主动开环控制方法研究。针对突扩面形成的大尺度旋涡脱落和运动是形成低频燃烧不稳定的主要原因,提出了在突扩截面上放置窄缝进行小流量空气喷射和燃气吸出的方法进行燃烧不稳定的开环主动控制。通过大涡模拟仿真表明,这两种方式都能够比较有效地干扰突扩面上大尺度旋涡的形成和破坏振动能量的正反馈,起到较好的抑制效果,压强振动幅值分别下降了48%和54%。

Large eddy simulation（LES） coupling with multi-step chemical mechanisms was used to investigate open-loop active control of low-frequency combustion instabilities in a dump combustor.For large vortex structures shedding from dump plane and propagating play a key role in low frequency unsteady combustion,the air injection and gas suction through small slot on dump plane were proposed to control combustion instabilities.Simulation results indicate that formation of large scale vortices from dump plane is effectively destroyed and positive feedback mechanism of oscillation energy is interrupted.Air injection and gas suction are both effective to suppress pressure oscillations,with their magnitudes decrease by 48% and 54% respectively.