叶片表面粗糙度对高负荷低压涡轮的流动影响
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摘要
为了得到不同工况下表面粗糙度对涡轮叶片叶型损失的影响规律,采用数值模拟的方法对某前加载叶型在不同攻角和不同雷诺数下的流动进行了详细的分析。结果表明,当攻角i=0°、10°时,叶片表面并无明显的分离现象出现,当i=20°、25°、30°时,叶片表面都出现了不同程度的分离,且攻角越大分离越严重。当攻角一定时,增大雷诺数对抑制分离泡的出现有促进作用;当雷诺数也一定时,增大叶片表面粗糙度对抑制附面层的分离有明显的效果,且雷诺数越大抑制分离所需的粗糙度值就越低。攻角为20°,雷诺数分别等于25 000、50 000、100 000、150 000、200 000时,抑制分离所需的最佳粗糙度值依次为38、14、5.1、2.5、1.7 mm;攻角为25°,相同雷诺数下抑制分离所需的最佳粗糙度值依次为230、50、11、4、2.2 mm;攻角为30°,雷诺数分别等于50 000、100 000、150 000、200 000时,抑制分离所需的最佳粗糙度值依次为3 200、800、120、29 mm。最后,建立了一套不同攻角下抑制分离的最佳粗糙度-雷诺数关系模型,并编写了相应的C语言程序。通过该程序,只要得知叶片工作的攻角与雷诺数大小,便可直接算出抑制附面层分离的最佳粗糙度值。
In order to get the effects of surface roughness on turbine profile loss in different working conditions, the flow of a front-loaded blade at different incidences and different Reynolds number was analyzed in detail by numerical simulation. The results show that when the incidence i=0° and 10°, there are no obvious separation on the blade surface. When i=20°, 25° and 30°, the boundary layer on blade surface are separated and the incidence is more serious. When the incidence is certain, the increasing of Reynolds number on the suppression of separation bubble appears to have a role in promoting; when the Reynolds number also is certain, increase the blade surface roughness of suppression of boundary layer separation have obvious effect, and Reynolds number greater suppression required to separate the roughness value is lower. When i=20° and the Reynolds number is 25 000,50 000,100 000,150 000,200 000, the optimal roughness value of suppressing separation is 38 mm,14 mm,5.1 mm,2.5 mm,1.7 mm, When i=25°, the optimal roughness value of suppressing separation is 230 mm,50 mm,11 mm, 4 mm,2.2 mm to the same Reynolds number, When i=30° and the Reynolds number is 50 000, 100 000, 150 000, 200 000, the optimal roughness value of suppressing separation is 3 200 mm,800 mm,120 mm,29 mm. Finally, a modal of optimal roughness vs. Reynolds number was built for suppressing separation in different incidences, and a C language program was written by the model. By using the program, the optimal roughness value of suppressing boundary layer separation can be calculated directly from the certain incidence and Reynolds number.
In order to get the effects of surface roughness on turbine profile loss in different working conditions, the flow of a front-loaded blade at different incidences and different Reynolds number was analyzed in detail by numerical simulation. The results show that when the incidence i=0° and 10°, there are no obvious separation on the blade surface. When i=20°, 25° and 30°, the boundary layer on blade surface are separated and the incidence is more serious. When the incidence is certain, the increasing of Reynolds number on the suppression of separation bubble appears to have a role in promoting; when the Reynolds number also is certain, increase the blade surface roughness of suppression of boundary layer separation have obvious effect, and Reynolds number greater suppression required to separate the roughness value is lower. When i=20° and the Reynolds number is 25 000,50 000,100 000,150 000,200 000, the optimal roughness value of suppressing separation is 38 mm,14 mm,5.1 mm,2.5 mm,1.7 mm, When i=25°, the optimal roughness value of suppressing separation is 230 mm,50 mm,11 mm, 4 mm,2.2 mm to the same Reynolds number, When i=30° and the Reynolds number is 50 000, 100 000, 150 000, 200 000, the optimal roughness value of suppressing separation is 3 200 mm,800 mm,120 mm,29 mm. Finally, a modal of optimal roughness vs. Reynolds number was built for suppressing separation in different incidences, and a C language program was written by the model. By using the program, the optimal roughness value of suppressing boundary layer separation can be calculated directly from the certain incidence and Reynolds number.
引文
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[3] DENTON J D.Loss Mechanisms in Turbomachines[J].Journal of Turbo-machinery,1993,115(4):621.
[4] SCHULTE V,HODSON H P.Unsteady Wake-Induced Boundary Layer Transition in High Lift LP Turbines[J].Journal of Turbo-machinery,1998,120(1):28.
[5] ZHANG X F,VERA M,HODSON H P,et al.Separation and Transition Control on An Aft-loaded Ultra-high-lift LP Turbine Blade at Low Reynolds Numbers:Low-Speed Investigation[R].ASME paper 2005-GT-68892,2005.
[6] 杨林,乔渭阳,罗华玲,等.低雷诺数高负荷低压涡轮叶型的气动设计[J].航空动力学报,2013,28(5):1019.
[7] 杜强,朱俊强,温殿中.高负荷低压涡轮边界层转捩预测及其机理分析[J].工程热物理学报,2010,31(5):761.
[8] 孙爽,雷志军,朱俊强,等.粗糙度对超高负荷低压涡轮边界层影响[J].推进技术,2014,35(3):347.
[9] BENNER M W,SJOLANDER S A,MOUSTAPHA S H.Measurements of Secondary Flows Downstream of a Turbine Cascade at Off-design Incidence[R].ASME GT 2004-53786,2004.
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[11] ROBERTS S K,YARAS M I.Effects of Surface-Roughness Geometry on Separation-Bubble Transition[J].Journal of Turbo-machinery,2006,128(2):349.
[12] FRANCESCO Montomoli,HOWARD Hodson.Effect of Roughness and Unsteadiness on the Performance of a New Low Pressure Turbine Blade at Low Reynolds Numbers[J].Journal of Turbo-machinery,2010,132(3):031018.
[13] 白涛.叶片几何偏差对涡轮性能的影响[D].北京:北京航空航天大学,2013.
[14] 张仪,王晓东,胡昊,等.湍流模型对湍流射流CFD模拟的影响[J].推进技术,2016,37(6):1049.
[15] 张波,李伟,杜强,等.U型槽对高负荷低压涡轮叶型攻角特性影响[J].航空动力学报,2012,27(7):1503.
[16] SCHILICHTING H.Experiment Investigation of the Problem of Surface Roughness[R].NACA Technical Memorandum,1937,823(4),1937.
[17] NIKURADSE J.Law of Flow in Rough Pipe[M].Technical Memordum 1292 NACA,1950.
[18] MARCO Montis,ANDREAS Fiala.Effect of Surface Roughness on Loss Behavior,Aerodynamic Loading and Boundary Layer Development of a Low-pressure Gas Turbine Airfoil[R].ASME GT2010-23317,2010.
[19] 孙爽,雷志军,卢新根,等.来流条件对超高负荷低压涡轮附面层非定常特性影响的实验研究[J].推进技术,2016,37(4):653.
[20] HODSON H P,HOWELL R J.The Role of Transition in High-lift Low-pressure Turbines for Aero Engine[J].Progress in Aerospace Science,2005,41:419.
[21] 高磊,王子楠,耿少娟,等.粗糙度对压气机叶栅损失特性影响的实验研究[J].推进技术,2016,37(7):1263.
[22] 孙爽,雷志军,卢新根,等.基于表面粗糙度的超高负荷低压涡轮叶片附面层控制[J].航空动力学报,2016,31(4):836.
[23] GEERS T L.Objective Error Measure for the Comparison of Calculated and Measured Transient Response Histories[J].Shock and Vibration Bulletin,1984,54:99.
[2] HOWELL R J.Wake Separation Bubble Interactions in Low Reynolds Number Turbo-machinery [D].Cambridge:Cambridge University,1999.
[3] DENTON J D.Loss Mechanisms in Turbomachines[J].Journal of Turbo-machinery,1993,115(4):621.
[4] SCHULTE V,HODSON H P.Unsteady Wake-Induced Boundary Layer Transition in High Lift LP Turbines[J].Journal of Turbo-machinery,1998,120(1):28.
[5] ZHANG X F,VERA M,HODSON H P,et al.Separation and Transition Control on An Aft-loaded Ultra-high-lift LP Turbine Blade at Low Reynolds Numbers:Low-Speed Investigation[R].ASME paper 2005-GT-68892,2005.
[6] 杨林,乔渭阳,罗华玲,等.低雷诺数高负荷低压涡轮叶型的气动设计[J].航空动力学报,2013,28(5):1019.
[7] 杜强,朱俊强,温殿中.高负荷低压涡轮边界层转捩预测及其机理分析[J].工程热物理学报,2010,31(5):761.
[8] 孙爽,雷志军,朱俊强,等.粗糙度对超高负荷低压涡轮边界层影响[J].推进技术,2014,35(3):347.
[9] BENNER M W,SJOLANDER S A,MOUSTAPHA S H.Measurements of Secondary Flows Downstream of a Turbine Cascade at Off-design Incidence[R].ASME GT 2004-53786,2004.
[10] BENNER M W,SJOLANDER S A,MOUSTAPHA S H.Measurements of Secondary Flows in Turbine Cascade at Off-design Incidence[R].ASME Turbo Expo,GT 97-382,1997.
[11] ROBERTS S K,YARAS M I.Effects of Surface-Roughness Geometry on Separation-Bubble Transition[J].Journal of Turbo-machinery,2006,128(2):349.
[12] FRANCESCO Montomoli,HOWARD Hodson.Effect of Roughness and Unsteadiness on the Performance of a New Low Pressure Turbine Blade at Low Reynolds Numbers[J].Journal of Turbo-machinery,2010,132(3):031018.
[13] 白涛.叶片几何偏差对涡轮性能的影响[D].北京:北京航空航天大学,2013.
[14] 张仪,王晓东,胡昊,等.湍流模型对湍流射流CFD模拟的影响[J].推进技术,2016,37(6):1049.
[15] 张波,李伟,杜强,等.U型槽对高负荷低压涡轮叶型攻角特性影响[J].航空动力学报,2012,27(7):1503.
[16] SCHILICHTING H.Experiment Investigation of the Problem of Surface Roughness[R].NACA Technical Memorandum,1937,823(4),1937.
[17] NIKURADSE J.Law of Flow in Rough Pipe[M].Technical Memordum 1292 NACA,1950.
[18] MARCO Montis,ANDREAS Fiala.Effect of Surface Roughness on Loss Behavior,Aerodynamic Loading and Boundary Layer Development of a Low-pressure Gas Turbine Airfoil[R].ASME GT2010-23317,2010.
[19] 孙爽,雷志军,卢新根,等.来流条件对超高负荷低压涡轮附面层非定常特性影响的实验研究[J].推进技术,2016,37(4):653.
[20] HODSON H P,HOWELL R J.The Role of Transition in High-lift Low-pressure Turbines for Aero Engine[J].Progress in Aerospace Science,2005,41:419.
[21] 高磊,王子楠,耿少娟,等.粗糙度对压气机叶栅损失特性影响的实验研究[J].推进技术,2016,37(7):1263.
[22] 孙爽,雷志军,卢新根,等.基于表面粗糙度的超高负荷低压涡轮叶片附面层控制[J].航空动力学报,2016,31(4):836.
[23] GEERS T L.Objective Error Measure for the Comparison of Calculated and Measured Transient Response Histories[J].Shock and Vibration Bulletin,1984,54:99.