本文使用PIV对在坚直通道内放置一个特殊设计的隔板所形成的湍流混合层流动进行测量,高低侧速比为4:1,基于两股流体速度差和管道水力半径的Re数范围4400~158400.发现混合层中大涡拟序结构的尺度随雷诺数的增加而增大,而后又随雷诺数的继续增大而减小,气泡的加入会延缓或阻碍大涡拟序结构的发展.对雷诺应力、湍流强度、涡量、旋涡强度在混合层流场内随雷诺数的变化和分布规律进行分析,发现混合层内雷诺应力、湍流强度、涡量及旋涡强度均集中分布在隔板下游一个较窄的锥形区域内,雷诺应力和湍流强度随雷诺数的增大先增人后减小,随离开隔板距离的增大而减小.涡量及旋涡强度随雷诺数的增大而增加,随离开隔板距离的增大而减小.
参考文献
[1] | Brown GL;Roshko A .On Density Effects and Large Structure in Turbulent Mixing Layers[J].Journal of Fluid Mechanics,1974,64:775-816. |
[2] | C D Winant;F K Brownand .Vortex Pairing:the Mechanism of Turbulent Mixing-Layer Growth at Moderate Reynolds Number[J].Journal of Fluid Mechanics,1974,63:237-255. |
[3] | J C Lasheras;J S Cho;T Maxworthy .On the Origin and Evolution of Streamwise Vertical Structures in a Plane Free Shear Layer[J].Journal of Fluid Mechanics,1986,172:231-258. |
[4] | Chih Ming Ho;Lein Saing Huang .Subharmonics and Vortex Merging in Mixing Layers[J].Journal of Fluid Mechanics,1982,119:443-473. |
[5] | A K F Hussaln;A R Clark .On the Coherent Structure of the Axisymetric Mixing Layer a Flow Visualization Study[J].Journal of Fluid Mechanics,1981,104:263-294. |
[6] | Azim MA.;Islam AKMS. .Plane mixing layers from parallel and non-parallel merging of two streams[J].Experiments in Fluids: Experimental Methods and Their Applications to Fluid Flow,2003(2):220-226. |
[7] | Yoshitsugu Naka;Takeshi Omori;Shinnosuke Obi;Shigeaki Masuda .Simultaneous measurements of fluctuating velocity and pressure in a turbulent mixing layer[J].International journal of heat and fluid flow,2006(4):737-746. |
[8] | Diorio J;Kelley DH;Wallace JM .The spatial relationships between dissipation and production rates and vortical structures in turbulent boundary and mixing layers[J].Physics of fluids,2007(3):35101-1-35101-8-0. |
[9] | Rotter J;Fernando HJS;Kit E .Evolution of a forced stratified mixing layer[J].Physics of fluids,2007(6):65107-1-65107-10-0. |
[10] | Fritts DC.;Andreassen O.;Lie I.;Palmer TL. .EVOLUTION AND BREAKDOWN OF KELVIN-HELMHOLTZ BILLOWS IN STRATIFIED COMPRESSIBLE FLOWS .1. COMPARISON OF TWO- AND THREE-DIMENSIONAL FLOWS[J].Journal of the Atmospheric Sciences,1996(22):3173-3191. |
[11] | Palmer TL.;Andreassen O.;Fritts DC. .EVOLUTION AND BREAKDOWN OF KELVIN-HELMHOLTZ BILLOWS IN STRATIFIED COMPRESSIBLE FLOWS .2. INSTABILITY STRUCTURE, EVOLUTION, AND ENERGETICS[J].Journal of the Atmospheric Sciences,1996(22):3192-3212. |
[12] | E. Loth;M. S. Cebrzynski .Modulation of shear layer thickness due to large bubbles[J].International Journal of Multiphase Flow,1995(5):919-927. |
[13] | 于尚旺,姚朝晖,何枫.基于旋涡强度方法的冲击射流涡结构研究[J].清华大学学报(自然科学版),2006(08):1466-1469. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%