离心叶轮叶片前缘椭圆长短轴比对性能的影响
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摘要
使用数值研究方法研究了三个机器马赫数(Mu)下,小尺寸离心叶轮叶片前缘采用长短轴比例分别为1:1,2:1,3:1,4:1的椭圆形(圆形前缘可认为长短轴比为1:1)时叶片前缘附近流场情况及不同前缘形状对压缩机气动性能的影响(Mu主要应用于工程中,在离心压缩机中是用来衡量叶轮转速的一个无量纲量)。结果表明,椭圆形前缘随着长短轴比例的增大,可有效减小叶轮入口处的分离损失,使压缩机性能明显提高,喘振裕度及工作范围没有明显变化,并对结果进行了实验验证。经过静力分析,叶片前缘椭圆形长短轴比例的增加对叶轮强度影响不大。在小尺寸叶轮的设计和加工中,如压缩机在正常叶轮入口机器马赫数下运行(Mu=0.95附近),叶轮叶片前缘椭圆形长短轴比例对压缩机性能略有影响,可折衷考虑加工效率和压缩机性能;如压缩机在叶轮入口机器马赫数较高工况下运行较多(Mu大于1),叶轮叶片前缘椭圆形长短轴比例对压缩机性能影响较为显著,可将比例选为3:1或4:1。
The flow field near the elliptical blade leading edge of small-sized centrifugal impeller which respectively applied 1:1,2:1,3:1,4:1 as the axial ratio of ellipse and the effects of different leading edge shapes on aerodynamic performance of compressors were studied under three Mach number(Mu) by numerical simulations. The leading edge is circular when the axial ratio of the ellipse is 1:1. Mu is mainly applied in engineering project. It is a dimensionless quantity used to measure the rotating speed of the impeller in the field of compressor. The contrastive analysis results,which were obtained from a series of numerical simulations,show that separation loss near the inlet would be reduced with the rise of the axial ratio of elliptical blade leading edge,and performance of compressor was also significantly improved. At the same time,the surge margin and the range of working conditions did not show a clear change. Then the results were validated by performance experiments. The rise of the axial ratio of ellipse of blade leading edge had little impact on impeller strength through static analysis.During the manufacturing and designing process,if the compressor always is operated near Mu of 0.95,the effects of different axial ratios of ellipse of the leading edge on aerodynamic performance of compressors are little,and the tradeoff between the processing efficiency as well as the performance of the compressor could be made. If the compressor is always operated under Mu of 1 or bigger,the effects are obvious and the axial ratio should be 3:1 or 4:1.
The flow field near the elliptical blade leading edge of small-sized centrifugal impeller which respectively applied 1:1,2:1,3:1,4:1 as the axial ratio of ellipse and the effects of different leading edge shapes on aerodynamic performance of compressors were studied under three Mach number(Mu) by numerical simulations. The leading edge is circular when the axial ratio of the ellipse is 1:1. Mu is mainly applied in engineering project. It is a dimensionless quantity used to measure the rotating speed of the impeller in the field of compressor. The contrastive analysis results,which were obtained from a series of numerical simulations,show that separation loss near the inlet would be reduced with the rise of the axial ratio of elliptical blade leading edge,and performance of compressor was also significantly improved. At the same time,the surge margin and the range of working conditions did not show a clear change. Then the results were validated by performance experiments. The rise of the axial ratio of ellipse of blade leading edge had little impact on impeller strength through static analysis.During the manufacturing and designing process,if the compressor always is operated near Mu of 0.95,the effects of different axial ratios of ellipse of the leading edge on aerodynamic performance of compressors are little,and the tradeoff between the processing efficiency as well as the performance of the compressor could be made. If the compressor is always operated under Mu of 1 or bigger,the effects are obvious and the axial ratio should be 3:1 or 4:1.
引文
[1]Goodhand M N,Miller R J.The Impact of Real Geometries on Three-Dimensional Separations in Compressors[J].ASME Journal of Turbomachinery,2012,134(1).
[2]Wheeler A P S,Miller R J,Hodson H P.The Effect of Wake Induced Structures on Compressor Boundary-Layers[R].ASME GT 2006-90892.
[3]Henderson A,Walker G J,Hughes J.Unsteady Transition Phenomena at a Compressor Leading-Edge[R].ASME GT 2006-90641.
[4]陈雷,陈江,赵石磊,等.叶片前缘形状对涡轮气动性能的影响[J].航空动力学报,2013,28(4):921-929.
[5]初雷哲,杜建一,黄典贵,等.离心压气机叶片前缘几何形状对性能的影响[J].工程热物理学报,2008,29(5):767-769.
[6]陆宏志,徐力平,方韧.压气机叶片前缘形状的改进设计[J].航空动力学报,2000,15(2):129-132.
[7]Goodhand M N,Miller R J.Compressor Leading Edge Spikes:A New Performance Criterion[J].ASME Journal of Turbomachinery,2011,133(1).
[8]靳军,刘波,向南谊,等.超音速叶型前缘几何形状对叶栅气动性能的影响[J].航空动力学报,2007,22(4):660-665.
[9]Casartelli E,Saxer A P,Gyarmathy G.Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser with Leading Edge Redesign[J].ASME Journal of Turbomachinery,1999,121(1):119-126.
[10]刘宝杰,袁春香,于贤君.前缘形状对可扩散叶型性能影响[J].推进技术,2013,34(7):890-897.(LIU Bao-jie,YUAN Chun-xiang,YU Xian-jun.Effect of Leading-Edge Geometry on Aerodynamic Performance in Controlled Diffusion Airfoil[J].Journal of Propulsion Technology,2013,34(7):890-897.)
[11]Walraevens R E,Compsty N A.Leading Edge Separation Bubbles on Turbomachine Blades[R].ASME 93-GT-91.
[12]Wheeler A P S,Sofia A,Miller R J.The Effect of Leading-Edge Geometry on Wake Interactions in Compressors[J].ASME Journal of Turbomachinery,2009,131(4).
[13]刘火星,蒋浩康,陈懋章.压气机叶片前缘分离流动[J].工程热物理学报,2004,25(6):936-939.
[14]刘火星,李凌,蒋浩康,等.二维NACA65叶型前缘几何形状对气动性能的影响[J].工程热物理学报,2003,24(2):231-233.
[15]陆宏志,徐力平.压气机叶片的带平台圆弧形前缘[J].推进技术,2003,24(6):532-536.(LU Hongzhi,XU Li-ping.Circular Leading Edge with a Flat for Compressor Blades[J].Journal of Propulsion Technology,2003,24(6):532-536.)
[16]Barth T J,Jesperson D C.The Design and Application of Upwind Schemes on Unstructured Meshes[R].AIAA89-0366.
[17]孙涛,王毅,王晓放,等.离心压缩机叶片前缘形状对强度计算的影响[J].风机技术,2011,(2):24-27.
[18]魏兆正.材料力学[M].大连:大连理工大学出版社,1994.
[2]Wheeler A P S,Miller R J,Hodson H P.The Effect of Wake Induced Structures on Compressor Boundary-Layers[R].ASME GT 2006-90892.
[3]Henderson A,Walker G J,Hughes J.Unsteady Transition Phenomena at a Compressor Leading-Edge[R].ASME GT 2006-90641.
[4]陈雷,陈江,赵石磊,等.叶片前缘形状对涡轮气动性能的影响[J].航空动力学报,2013,28(4):921-929.
[5]初雷哲,杜建一,黄典贵,等.离心压气机叶片前缘几何形状对性能的影响[J].工程热物理学报,2008,29(5):767-769.
[6]陆宏志,徐力平,方韧.压气机叶片前缘形状的改进设计[J].航空动力学报,2000,15(2):129-132.
[7]Goodhand M N,Miller R J.Compressor Leading Edge Spikes:A New Performance Criterion[J].ASME Journal of Turbomachinery,2011,133(1).
[8]靳军,刘波,向南谊,等.超音速叶型前缘几何形状对叶栅气动性能的影响[J].航空动力学报,2007,22(4):660-665.
[9]Casartelli E,Saxer A P,Gyarmathy G.Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser with Leading Edge Redesign[J].ASME Journal of Turbomachinery,1999,121(1):119-126.
[10]刘宝杰,袁春香,于贤君.前缘形状对可扩散叶型性能影响[J].推进技术,2013,34(7):890-897.(LIU Bao-jie,YUAN Chun-xiang,YU Xian-jun.Effect of Leading-Edge Geometry on Aerodynamic Performance in Controlled Diffusion Airfoil[J].Journal of Propulsion Technology,2013,34(7):890-897.)
[11]Walraevens R E,Compsty N A.Leading Edge Separation Bubbles on Turbomachine Blades[R].ASME 93-GT-91.
[12]Wheeler A P S,Sofia A,Miller R J.The Effect of Leading-Edge Geometry on Wake Interactions in Compressors[J].ASME Journal of Turbomachinery,2009,131(4).
[13]刘火星,蒋浩康,陈懋章.压气机叶片前缘分离流动[J].工程热物理学报,2004,25(6):936-939.
[14]刘火星,李凌,蒋浩康,等.二维NACA65叶型前缘几何形状对气动性能的影响[J].工程热物理学报,2003,24(2):231-233.
[15]陆宏志,徐力平.压气机叶片的带平台圆弧形前缘[J].推进技术,2003,24(6):532-536.(LU Hongzhi,XU Li-ping.Circular Leading Edge with a Flat for Compressor Blades[J].Journal of Propulsion Technology,2003,24(6):532-536.)
[16]Barth T J,Jesperson D C.The Design and Application of Upwind Schemes on Unstructured Meshes[R].AIAA89-0366.
[17]孙涛,王毅,王晓放,等.离心压缩机叶片前缘形状对强度计算的影响[J].风机技术,2011,(2):24-27.
[18]魏兆正.材料力学[M].大连:大连理工大学出版社,1994.