基于DMD方法的无叶扩压器流动稳定性分析  

Analysis on the Hydrodynamic Stability of a Vaneless Diffuser Based on Dynamic Mode Decomposition

作　　者：吴蔚 赵博[1] 竺晓程[1] 杜朝辉[1] WU Wei;ZHAO Bo;ZHU Xiaocheng;DU Zhaohui(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《动力工程学报》2020年第5期365-370,共6页Journal of Chinese Society of Power Engineering

基　　金：国防基础科研计划资助项目(B1420110136)。

摘　　要：针对无叶扩压器的失稳现象,采用计算流体动力学(CFD)方法对二维无叶扩压器在不同入口流动角下收敛和发散过程中的非定常流场进行动力模态分解(DMD),并对非定常计算过程中稳定和不稳定工况的变化流场进行了分析。结果表明:通过DMD方法获得的模态特征与二维无黏线性化稳定性分析得到的结果基本一致,在不稳定工况下具有相同的周向模态数以及相近的失速团相对叶轮转速。To improve the stability of a vaneless diffuser,the unsteady flow fields in the process of convergence and divergence were analyzed by dynamic mode decomposition(DMD)based on the model of two-dimensional vaneless diffuser at different inlet flow angles,while the flow field variation was analyzed during the unsteady calculation under stable and unstable operating conditions.Results show that the modal characteristics obtained under unstable condition by DMD method are close to that by two-dimensional non-viscous linearization stability model,including the number of circumferential modes and the rotation speed of stall cells.

关 键 词：无叶扩压器 旋转失速 动力模态分解 临界流动角 

分 类 号：TH452[机械工程—机械制造及自动化]