离心压缩机叶片扩压器内流场模态与失稳分析
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摘要
离心式压缩机中叶片扩压器叶片和旋转叶轮间流动存在动静干涉,易出现流动不稳定现象。模态分解方法用于提取出动态流场中相关的模态流场信息。本文在离心式压缩机叶片扩压器动态流场应用动态模式分解方法,对速度场提取模态并进行分析,结果表明:叶片扩压器近盘盖侧涡结构运动规律不同,90%叶高平面涡沿着叶片压力面向下游运动并很快耗散,而在10%叶高平面涡会进入通道造成流动不稳定。随着流量减小,10%叶高面上叶片吸力面尾缘产生大尺度涡并脱落,进一步加剧盘侧截面恶劣的流通情况。
The rotor-stator interaction of rotating impeller and vaned diffuser often cause the unsteady flow.The model decomposition method can be used to extract the coherent structures.In this paper,the dynamic mode decomposition method is applied to extract and analyze the dynamic modes of velocity field of vaned diffuser in centrifugal compressor.The result shows the movement rules of the vortex at close to the shroud spans in vaned diffuser which the vortex of 90% vane height moves downstream along the vane pressure surface and disappears quickly,the vortex of 10% vane height enter the flow passage cause the flow unsteady.As the flow rate decrease,the large scale vortex come out and disappeared in the suction surface trailing edge of 10% vaned height that the flow condition in the blade side become deteriorates.
The rotor-stator interaction of rotating impeller and vaned diffuser often cause the unsteady flow.The model decomposition method can be used to extract the coherent structures.In this paper,the dynamic mode decomposition method is applied to extract and analyze the dynamic modes of velocity field of vaned diffuser in centrifugal compressor.The result shows the movement rules of the vortex at close to the shroud spans in vaned diffuser which the vortex of 90% vane height moves downstream along the vane pressure surface and disappears quickly,the vortex of 10% vane height enter the flow passage cause the flow unsteady.As the flow rate decrease,the large scale vortex come out and disappeared in the suction surface trailing edge of 10% vaned height that the flow condition in the blade side become deteriorates.
引文
[1]Jr,R.C.D.,Senoo,Y.Rotating Wakes in Vaneless Diffusers[J].Journal of Fluids Engineering,1960,82(3):563.
[2]Eckardt,D.Detailed flow investigations within a high-speed centrifugal compressor impeller[J].Journal of Fluids Engineering,1976,98(3):390-402.
[3]Kai,U.Z.,Gallus,H.E.,Niehuis,R.A Study on Impeller-Diffuser Interaction—Part I:Influence on the Performance[J].Journal of Turbomachinery,2002,125(1):545-556.
[4]王彤,谷传纲.设计工况下离心压气机内部动静部件耦合非定常流动的数值模拟[J].机械工程学报,2001,37(3):20-24.
[5]Marsan,A.,Trébinjac,I.,Coste,S.,etc.Temporal behaviour of a corner separation in a radial vaned diffuser of a centrifugal compressor operating near surge[J].Journal of Thermal Science,2013,22(6):555-564.
[6]周俊安,刘立军,肖萍,等.带叶片扩压器离心压缩机模型级内流研究[J].西安交通大学学报,2015,49(9):30-35.
[7]Schmid,P.J.Dynamic mode decomposition of numerical and experimental data[J].Journal of fluid mechanics,2010,656 5-28.
[8]Rowley,C.W.,Mezic,I.,Bagheri,S.,etc.Spectral analysis of nonlinear flows[J].Journal of fluid mechanics,2009,641 115-127.
[9]Pan,C.,Xue,D.,Wang,J.On the accuracy of dynamic mode decomposition in estimating instability of wave packet[J].Experiments in Fluids,2015,56(8):164.
[10]邵昱昌,王彤.半开式离心叶轮与扩压器间流动模态提取与分析[J].风机技术,2017,59(4):1-7.
[11]薛翔,王彤,安正浩.基于小波变换相位差的压缩机内部模态失速先兆分析[J].风机技术,2017,59(3):20-28.
[2]Eckardt,D.Detailed flow investigations within a high-speed centrifugal compressor impeller[J].Journal of Fluids Engineering,1976,98(3):390-402.
[3]Kai,U.Z.,Gallus,H.E.,Niehuis,R.A Study on Impeller-Diffuser Interaction—Part I:Influence on the Performance[J].Journal of Turbomachinery,2002,125(1):545-556.
[4]王彤,谷传纲.设计工况下离心压气机内部动静部件耦合非定常流动的数值模拟[J].机械工程学报,2001,37(3):20-24.
[5]Marsan,A.,Trébinjac,I.,Coste,S.,etc.Temporal behaviour of a corner separation in a radial vaned diffuser of a centrifugal compressor operating near surge[J].Journal of Thermal Science,2013,22(6):555-564.
[6]周俊安,刘立军,肖萍,等.带叶片扩压器离心压缩机模型级内流研究[J].西安交通大学学报,2015,49(9):30-35.
[7]Schmid,P.J.Dynamic mode decomposition of numerical and experimental data[J].Journal of fluid mechanics,2010,656 5-28.
[8]Rowley,C.W.,Mezic,I.,Bagheri,S.,etc.Spectral analysis of nonlinear flows[J].Journal of fluid mechanics,2009,641 115-127.
[9]Pan,C.,Xue,D.,Wang,J.On the accuracy of dynamic mode decomposition in estimating instability of wave packet[J].Experiments in Fluids,2015,56(8):164.
[10]邵昱昌,王彤.半开式离心叶轮与扩压器间流动模态提取与分析[J].风机技术,2017,59(4):1-7.
[11]薛翔,王彤,安正浩.基于小波变换相位差的压缩机内部模态失速先兆分析[J].风机技术,2017,59(3):20-28.