毫米尺度下壁面粗糙度影响、微叶栅气流分离等内流问题研究
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摘要
毫米尺度低雷诺数下的流动特性研究是对厘米级微型涡轮发动机基础技术研究的重要组成部分。本文在这个条件下研究了壁面粗糙度对摩阻的影响和微型化后叶栅分离特性的变化。
首先,设计、加工了壁面含不同粗糙度值和不同粗糙度纹理方向的300mm×20mm×0.5mm矩形直通道,通过测量通道气流流量和沿程静压值,探索粗糙度大小及其纹理方向对气流流动特性的影响,揭示毫米尺度流动与常规尺度流动的不同点。实验结果表明在0.5mm高的微通道内,流动转捩雷诺数比常规尺度下小,约在400-1200之间;同一粗糙度量级下,横向、斜向纹理对气流流动的影响相对较大,转捩雷诺数比纵向纹理转捩雷诺数小;横向纹理产生的流动阻力最大,斜向的其次,纵向的最小。。
然后,参照NACA65-810叶型及其各项参数,设计、加工含5个微小叶栅通道的实验段,通过直径0.1mm的7个静压孔测量叶背处静压值,探究微型压气机平面叶栅的在不同来流角度下的气流分离规律,揭示其在低雷诺数下叶背气流分离与常规尺度下的不同,研究其微小尺度特性。微叶栅实验结果表明:在微小尺度下叶栅叶背处的压力系数比常规尺度下小的多;在攻角α1 =1.2时已经开始分离,气流分离区域在攻角α1 = 2.8、5.2、7. 2和9 .2下较常规尺度提前约15%弦长;在同一来流角度下,Re数在13300-38900范围内,随着Re的升高,压力系数S变大,但叶背处气流的分离位置基本不变。
The characteristics of millimeter-scale flow at low Reybolds number are one of the essential components for the design of centimeter-scale Micro Turbo Engine (MTE). On this condition, this paper reseached the effects of the wall roughness on the flow friction resistance and the different flow separation performance of the micro blades.
The first experimental investigation was made in the 300mm×20mm×0.5mm rectangular and straight micro channel with different roughness values and different roughness texture directions on the insides surface and consisted of flow flux measurements of the microchannel and static pressure measurements alone the channel for the goals to search the effect of different surface roughness values and different roughness texture directions on the flow characteristics and explore the difference characteristics between millimeter-scale flow and general flow. The results of this experimental investigation hereinbefore, together with other data, indicated the ideas that in the microchannel whose height was 0.5mm, Reynolds numbers when flow transition occurred on the extent of 400-1200 was less than the ones of the general scale. Furthermore, on the condition of the same roughness value level, there was more influence on the flow with the roughness of transverse direction and oblique direction than of longitudinal direction and Reynolds numbers when flow transition occurred was less, too. On the same condition, flow friction occured by the transverse direction roughness was greater than oblique direction roughness which was greater than longitudinal direction roughness, too.
After that, another experimental investigation was made in 5 micro compressor cascade channels which were designed on the foundation of NACA 65-810 blade airfoil and consisted of the 7 points static pressure measurements on the convex surface of the balde in the mid-channel via 7 micro static pressure holes whose diameter were all 0.1mm in order to search the flow separation laws of micro compressor cascade at different angles of attack and uncover the flow separation on the convex surface that’s different from the general-sacle. The results of this experimental investigation, together with other data, showed the conclusions that pressure coefficient of the convex surface was far less than the general and the laminar separation section move up about 15% of the chord. With the same angle of attack, pressure coefficient would ascend with the raise of Reynolds numbers on the extent of 13300-38900. On the whole, however, the separation position on the convex surface kept the same.
首先,设计、加工了壁面含不同粗糙度值和不同粗糙度纹理方向的300mm×20mm×0.5mm矩形直通道,通过测量通道气流流量和沿程静压值,探索粗糙度大小及其纹理方向对气流流动特性的影响,揭示毫米尺度流动与常规尺度流动的不同点。实验结果表明在0.5mm高的微通道内,流动转捩雷诺数比常规尺度下小,约在400-1200之间;同一粗糙度量级下,横向、斜向纹理对气流流动的影响相对较大,转捩雷诺数比纵向纹理转捩雷诺数小;横向纹理产生的流动阻力最大,斜向的其次,纵向的最小。。
然后,参照NACA65-810叶型及其各项参数,设计、加工含5个微小叶栅通道的实验段,通过直径0.1mm的7个静压孔测量叶背处静压值,探究微型压气机平面叶栅的在不同来流角度下的气流分离规律,揭示其在低雷诺数下叶背气流分离与常规尺度下的不同,研究其微小尺度特性。微叶栅实验结果表明:在微小尺度下叶栅叶背处的压力系数比常规尺度下小的多;在攻角α1 =1.2时已经开始分离,气流分离区域在攻角α1 = 2.8、5.2、7. 2和9 .2下较常规尺度提前约15%弦长;在同一来流角度下,Re数在13300-38900范围内,随着Re的升高,压力系数S变大,但叶背处气流的分离位置基本不变。
The characteristics of millimeter-scale flow at low Reybolds number are one of the essential components for the design of centimeter-scale Micro Turbo Engine (MTE). On this condition, this paper reseached the effects of the wall roughness on the flow friction resistance and the different flow separation performance of the micro blades.
The first experimental investigation was made in the 300mm×20mm×0.5mm rectangular and straight micro channel with different roughness values and different roughness texture directions on the insides surface and consisted of flow flux measurements of the microchannel and static pressure measurements alone the channel for the goals to search the effect of different surface roughness values and different roughness texture directions on the flow characteristics and explore the difference characteristics between millimeter-scale flow and general flow. The results of this experimental investigation hereinbefore, together with other data, indicated the ideas that in the microchannel whose height was 0.5mm, Reynolds numbers when flow transition occurred on the extent of 400-1200 was less than the ones of the general scale. Furthermore, on the condition of the same roughness value level, there was more influence on the flow with the roughness of transverse direction and oblique direction than of longitudinal direction and Reynolds numbers when flow transition occurred was less, too. On the same condition, flow friction occured by the transverse direction roughness was greater than oblique direction roughness which was greater than longitudinal direction roughness, too.
After that, another experimental investigation was made in 5 micro compressor cascade channels which were designed on the foundation of NACA 65-810 blade airfoil and consisted of the 7 points static pressure measurements on the convex surface of the balde in the mid-channel via 7 micro static pressure holes whose diameter were all 0.1mm in order to search the flow separation laws of micro compressor cascade at different angles of attack and uncover the flow separation on the convex surface that’s different from the general-sacle. The results of this experimental investigation, together with other data, showed the conclusions that pressure coefficient of the convex surface was far less than the general and the laminar separation section move up about 15% of the chord. With the same angle of attack, pressure coefficient would ascend with the raise of Reynolds numbers on the extent of 13300-38900. On the whole, however, the separation position on the convex surface kept the same.
引文
[1]黄国平,温泉,李博,梁德旺.微型涡喷发动机顶层设计研究[J].航空动力学报,2003,18(9):832-838.
[2]梁德旺,黄国平.厘米级微型涡轮喷气发动机主要研究进展[J].燃气涡轮试验与研究,2004.5,17(2):9-13.
[3] Epstein A H, Breuer K S, Lang J H,et al. Mirco Gas Turbine Generators[M].MIT,Cambridge.Gas Turbine Lab,Final Report. May 1, 1995- July 31, 2000.
[4] HangSojrg Schlip, Fabrication of Turbine-Compressor-Shaft Assemble For Micro Gas Turbine Engine[D]. Mater’s Theiss, Standford Univ, December 2000.
[5] HangSojrg Schlip, Kang S,Stampfl J,Cooper A G, Prinz F B.Application of the Mold SDM Process to the Fabrication of Ceramic Parts for a Micro Gas Turbine Engine[R].Heinrich J G(ed), Proceeding Ceramics Materials and Components for Engines,Germany,2000.
[6] Mindi Farber De Anda,Christina Maath,Ndeye K Fall Distributed Energy Technology Simulator Microturbine Demonstration[R].Energetics Inc Washtington.DC,2001.
[7] Mikbs Gerendas,Ralph pfister.Development of A Very Small Aero-Engine[R].Processdings of AMSE TurboExpo 2000,45th ASNE International Gas Turbine and Aero-Engine Technical Congress and Exposition,2000-GT-0536.
[8] Epstein A H. Micro Turbo Machinery (Gas turbo engine)[P]. US PATENT:5,932-940.
[9] Epstein A H, Senturia. S D, Anathasuresh G, et al. Power MEMS and Microengines [A]. Proceedings of the 1997 International Conference on Solid-State Sensors and Actuators[C]. Chicago,1997, 753-756.
[10] Kandlikar S G,Grande W J.Evolution of Microchannel Flow Passages-Thermohydraulic Performance and Fabrication Technology[C]. Proceedings of IMECE2002 ,ASME International Mechanical Engineering Congress&Exposition,November,2002,New Orleans,Louisiana.
[11] Tuckmann D B,Peace R F.Optimized Convective Cooling Using Micromachined Structure [J].Electrochem.Soctland.1982,129(3),C98.
[12]江小宁,周兆英等.微流体运动的试验研究[J].光学精密工程,1995,3(3):51-55.
[13] Pong K C,Ho C M ,et al.Non-linear Pressure Distribution in Uniform Microchannels[J].ASME FED, 1994,Vol.197:51-56.
[14]杜东兴等.微细光滑管内的气体流动阻力特性[J].中国科学(E辑),2000, 30(2):321-326.
[15] Papautsky I,Ameel T.A Review of Laminar Single-phase Flow in Microchannels[C].ASMEInternational Mechanical Engineering Congress and Exposition,November,2001,New York.
[16] George Em Karniadakis,Ali Beskok,中科院过程工程研究所多相反应重点实验室译.Micro Flows Fundamentals and Simulation[M].北京:化学工业出版社,2006.
[17]马吉.微小通道内低雷诺数流动的实验研究[D].南京航空航天大学硕士论文,2004.
[18]戚峰.微尺度射流、壁面边界层及叶栅流动实验研究[D].南京航空航天大学硕士论文,2006.
[19] Gad-el-hak M. The Fluid Mechanics of Micro Devices[J]. Fluids Engineering,ASME,1999,Vol.121:5-33.
[20]梁德旺.流体力学基础[M].北京:航空工业出版社,1998.
[21]凌智勇,丁建宁,杨继昌,范真,李长生.微流动的研究现状及影响因素[J].江苏大学学报(自然科学版),2002,23(6):1-5.
[22] P.Wu,W A Little.Measurement of Friction Factors for the Flow of Gases in Very Fine Channels Used for Microminiature Joule-Thomson Refrigerators[J].Cryogenics,1984,Vol.5:273-277.
[23] Peng X F et al.The Effect of Theromofluid and Geometrical Parameters on Convection of Liquids Through Rectangular Microchannels[J].Heat Mass Transfer,1996,Vol.38:755-758.
[24]唐桂华,何雅玲,陶文铨.粗糙度与气体稀薄性对微尺度流动特性的影响[J].工程热物理学报,2006.3,27(2):304-306.
[25] Sabry M N. Scale Effects on Flow and Hear Transfer in Microchannels [J].IEEE Transactions on Components and Packing Technologies.2000,23(3):562-567.
[26]杜东兴等.微细光滑管内的气体流动阻力特性[J].中国科学(E辑),2000,30(2):173-178.
[27]刘火星,陈懋章等.压气机叶片前缘分离流动[J].工程热物理学报,2004,25(6):936-939.
[28]郑新前,候安平,周盛.二维扩压叶栅非定常分离流控制途径探索[J].力学学报,2003.9, 35(5):599-605.
[29] James C.Emery,L.Joseph Herrig,et al.Systematic Two-Dimensional Cascade Tests of NACA 65-Series Compressor Blade at Low Speeds[R].National Advisory Committee For Aeronautics,1958.
[30]黄永湘,颜世忠.建立分离器流出气体均流流场的模拟试验[J].油气田地面工程,1995.3,Vol.14(2):44-46.
[31]李志辉,张涵信,符松.用于Poiseuille等微槽道流的Boltzmann模型方程算法研究[J].中国科学(G辑),2005,35(3):271-291.
[32]顾帅华,黄国平,雷雨冰.微小直通道表面粗糙度对流动特性的影响[C].中国航空学会第七届小型发动机学术交流会论文集.哈尔滨,2007.12.
[33] White F M,陈建宏译.流体力学[M].北京:晓园出版社,1986年第二版.
[34]陈少龙,侯安平,周盛.扩压式叶栅非定常分离流机理研究的频谱分析[J].航空动力学报,2003,18(3):336-342.
[35]张涵信.分离流动概论(上册)[M].南京:南京航空航天大学图书馆资料室,1987.
[36]夏雪湔,邓学蓥.工程分离流动力学[M].北京:北京航空航天大学出版社,1991.
[37]张涵信,陆林生,余泽楚.分离点附近流线的性状及分离判据[J].力学学报,1983,3:227-232.
[38]庄逢甘,张涵信.分离流动研究的进展[J].空气动力学学报,1984,4:1-9.
[39]黄国平.粘性流体力学基础[M].南京航空航天大学能源与动力学院,2005.8.
[40] William J.Bursnall, Laurence K.Loftin, Jr. Experimental Investigation of Localized Regions of Laminar-boundary-layer Separation[R]. National Advisory Committee for Aeronautics, NT 2338, April 1951.
[41]陈克成.流体力学实验技术[M].北京:机械工业出版社,1983.
[42] Shaw R. The Influence of Hole Dimension on Static Pressure Measurement[J]. Fluid.Mech.1960,7(4).
[43]刘火星,陈懋章等.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.
[2]梁德旺,黄国平.厘米级微型涡轮喷气发动机主要研究进展[J].燃气涡轮试验与研究,2004.5,17(2):9-13.
[3] Epstein A H, Breuer K S, Lang J H,et al. Mirco Gas Turbine Generators[M].MIT,Cambridge.Gas Turbine Lab,Final Report. May 1, 1995- July 31, 2000.
[4] HangSojrg Schlip, Fabrication of Turbine-Compressor-Shaft Assemble For Micro Gas Turbine Engine[D]. Mater’s Theiss, Standford Univ, December 2000.
[5] HangSojrg Schlip, Kang S,Stampfl J,Cooper A G, Prinz F B.Application of the Mold SDM Process to the Fabrication of Ceramic Parts for a Micro Gas Turbine Engine[R].Heinrich J G(ed), Proceeding Ceramics Materials and Components for Engines,Germany,2000.
[6] Mindi Farber De Anda,Christina Maath,Ndeye K Fall Distributed Energy Technology Simulator Microturbine Demonstration[R].Energetics Inc Washtington.DC,2001.
[7] Mikbs Gerendas,Ralph pfister.Development of A Very Small Aero-Engine[R].Processdings of AMSE TurboExpo 2000,45th ASNE International Gas Turbine and Aero-Engine Technical Congress and Exposition,2000-GT-0536.
[8] Epstein A H. Micro Turbo Machinery (Gas turbo engine)[P]. US PATENT:5,932-940.
[9] Epstein A H, Senturia. S D, Anathasuresh G, et al. Power MEMS and Microengines [A]. Proceedings of the 1997 International Conference on Solid-State Sensors and Actuators[C]. Chicago,1997, 753-756.
[10] Kandlikar S G,Grande W J.Evolution of Microchannel Flow Passages-Thermohydraulic Performance and Fabrication Technology[C]. Proceedings of IMECE2002 ,ASME International Mechanical Engineering Congress&Exposition,November,2002,New Orleans,Louisiana.
[11] Tuckmann D B,Peace R F.Optimized Convective Cooling Using Micromachined Structure [J].Electrochem.Soctland.1982,129(3),C98.
[12]江小宁,周兆英等.微流体运动的试验研究[J].光学精密工程,1995,3(3):51-55.
[13] Pong K C,Ho C M ,et al.Non-linear Pressure Distribution in Uniform Microchannels[J].ASME FED, 1994,Vol.197:51-56.
[14]杜东兴等.微细光滑管内的气体流动阻力特性[J].中国科学(E辑),2000, 30(2):321-326.
[15] Papautsky I,Ameel T.A Review of Laminar Single-phase Flow in Microchannels[C].ASMEInternational Mechanical Engineering Congress and Exposition,November,2001,New York.
[16] George Em Karniadakis,Ali Beskok,中科院过程工程研究所多相反应重点实验室译.Micro Flows Fundamentals and Simulation[M].北京:化学工业出版社,2006.
[17]马吉.微小通道内低雷诺数流动的实验研究[D].南京航空航天大学硕士论文,2004.
[18]戚峰.微尺度射流、壁面边界层及叶栅流动实验研究[D].南京航空航天大学硕士论文,2006.
[19] Gad-el-hak M. The Fluid Mechanics of Micro Devices[J]. Fluids Engineering,ASME,1999,Vol.121:5-33.
[20]梁德旺.流体力学基础[M].北京:航空工业出版社,1998.
[21]凌智勇,丁建宁,杨继昌,范真,李长生.微流动的研究现状及影响因素[J].江苏大学学报(自然科学版),2002,23(6):1-5.
[22] P.Wu,W A Little.Measurement of Friction Factors for the Flow of Gases in Very Fine Channels Used for Microminiature Joule-Thomson Refrigerators[J].Cryogenics,1984,Vol.5:273-277.
[23] Peng X F et al.The Effect of Theromofluid and Geometrical Parameters on Convection of Liquids Through Rectangular Microchannels[J].Heat Mass Transfer,1996,Vol.38:755-758.
[24]唐桂华,何雅玲,陶文铨.粗糙度与气体稀薄性对微尺度流动特性的影响[J].工程热物理学报,2006.3,27(2):304-306.
[25] Sabry M N. Scale Effects on Flow and Hear Transfer in Microchannels [J].IEEE Transactions on Components and Packing Technologies.2000,23(3):562-567.
[26]杜东兴等.微细光滑管内的气体流动阻力特性[J].中国科学(E辑),2000,30(2):173-178.
[27]刘火星,陈懋章等.压气机叶片前缘分离流动[J].工程热物理学报,2004,25(6):936-939.
[28]郑新前,候安平,周盛.二维扩压叶栅非定常分离流控制途径探索[J].力学学报,2003.9, 35(5):599-605.
[29] James C.Emery,L.Joseph Herrig,et al.Systematic Two-Dimensional Cascade Tests of NACA 65-Series Compressor Blade at Low Speeds[R].National Advisory Committee For Aeronautics,1958.
[30]黄永湘,颜世忠.建立分离器流出气体均流流场的模拟试验[J].油气田地面工程,1995.3,Vol.14(2):44-46.
[31]李志辉,张涵信,符松.用于Poiseuille等微槽道流的Boltzmann模型方程算法研究[J].中国科学(G辑),2005,35(3):271-291.
[32]顾帅华,黄国平,雷雨冰.微小直通道表面粗糙度对流动特性的影响[C].中国航空学会第七届小型发动机学术交流会论文集.哈尔滨,2007.12.
[33] White F M,陈建宏译.流体力学[M].北京:晓园出版社,1986年第二版.
[34]陈少龙,侯安平,周盛.扩压式叶栅非定常分离流机理研究的频谱分析[J].航空动力学报,2003,18(3):336-342.
[35]张涵信.分离流动概论(上册)[M].南京:南京航空航天大学图书馆资料室,1987.
[36]夏雪湔,邓学蓥.工程分离流动力学[M].北京:北京航空航天大学出版社,1991.
[37]张涵信,陆林生,余泽楚.分离点附近流线的性状及分离判据[J].力学学报,1983,3:227-232.
[38]庄逢甘,张涵信.分离流动研究的进展[J].空气动力学学报,1984,4:1-9.
[39]黄国平.粘性流体力学基础[M].南京航空航天大学能源与动力学院,2005.8.
[40] William J.Bursnall, Laurence K.Loftin, Jr. Experimental Investigation of Localized Regions of Laminar-boundary-layer Separation[R]. National Advisory Committee for Aeronautics, NT 2338, April 1951.
[41]陈克成.流体力学实验技术[M].北京:机械工业出版社,1983.
[42] Shaw R. The Influence of Hole Dimension on Static Pressure Measurement[J]. Fluid.Mech.1960,7(4).
[43]刘火星,陈懋章等.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.