Reynolds number influence on statistical behaviors of turbulence in a circular free jet | |
Mi, J. ; Xu, M. ; Zhou, T. | |
刊名 | physics of fluids
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2013 | |
关键词 | ENERGY-DISSIPATION RATE SMALL-SCALE TURBULENCE ROUND JET ISOTROPIC TURBULENCE VELOCITY-FIELD TEMPERATURE DERIVATIVES NUMERICAL SIMULATIONS AXISYMMETRICAL JETS TAYLOR HYPOTHESIS FLOWS |
DOI | 10.1063/1.4811403 |
英文摘要 | The present paper examines the effect of Reynolds number on turbulence properties in the transition region of a circular jet issuing from a smoothly contracting nozzle. Hot-wire measurements were performed for this investigation through varying the jet-exit Reynolds number Re-d (equivalent to U(j)d/nu, where U-j, d, and nu are the jet-exit mean velocity, nozzle diameter, and kinematic viscosity) approximately from Re-d approximate to 4 x 10(3) to Re-d approximate to 2 x 10(4). Results reveal that the rates of the mean flow decay and spread vary with Reynolds number for Re-d < 10(4) and tend to become Reynolds-number independent at Re-d >= 10(4). Even more importantly, the small-scale turbulence properties, e. g., the mean rate of dissipation of kinetic energy (epsilon), the Kolmogorov and Taylor microscales, are found to vary in different forms over the Re-d ranges of Re-d > 10(4) and Re-d < 10(4). Namely, the critical Reynolds number appears to occur at Re-d,Re-cr approximate to 10(4) across which the jet turbulence behaves distinctly. Two turbulence regimes are therefore identified: (i) developing or partially developed turbulence at Re-d < Re-d,Re-cr and (ii) fully developed turbulence at Re-d >= Re-d,Re-cr. It is suggested that the energy dissipation rate (DR) can be expressed as epsilon similar to nu U-c(2)/R-2 in regime (i) and epsilon similar to U-c(3)/R in regime (ii), where U-c and R are the centerline (or maximum) mean velocity and half-radius at which the mean velocity is 0.5U(c). In addition, the critical Reynolds number appears to vary from flow to flow. (C) 2013 AIP Publishing LLC.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000322521100041&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Mechanics; Physics, Fluids & Plasmas; SCI(E); EI; 11; ARTICLE; 7; 25 |
语种 | 英语 |
内容类型 | 期刊论文 |
源URL | [http://ir.pku.edu.cn/handle/20.500.11897/154461] ![]() |
专题 | 工学院 |
推荐引用方式 GB/T 7714 | Mi, J.,Xu, M.,Zhou, T.. Reynolds number influence on statistical behaviors of turbulence in a circular free jet[J]. physics of fluids,2013. |
APA | Mi, J.,Xu, M.,&Zhou, T..(2013).Reynolds number influence on statistical behaviors of turbulence in a circular free jet.physics of fluids. |
MLA | Mi, J.,et al."Reynolds number influence on statistical behaviors of turbulence in a circular free jet".physics of fluids (2013). |
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