The influence of Reynolds number on a plane jet

doi:10.1063/1.2959171

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	The influence of Reynolds number on a plane jet
	Deo, Ravinesh C. ; Mi, Jianchun ; Nathan, Graham J.
刊名	physics of fluids
	2008
关键词	TURBULENT JET 2-DIMENSIONAL JET FIELD TRANSITION BEHAVIOR VELOCITY DERIVATIVES MOTION SCALAR FLOWS
DOI	10.1063/1.2959171
英文摘要	The present study systematically investigates through experiments the influence of Reynolds number on a plane jet issuing from a radially contoured, rectangular slot nozzle of large aspect ratio. Detailed velocity measurements were performed for a jet exit Reynolds number spanning the range 1500 <= Re(h)<= 16 500, where Re(h)equivalent to U(b)h/upsilon with U(b) as the momentum-averaged exit mean velocity, h as the slot height, and upsilon as the kinematic viscosity. Additional centerline measurements were also performed for jets from two different nozzles in the same facility to achieve Re(h)=57 500. All measurements were conducted using single hot-wire anemometry to an axial distance (x) of x <= 160h. These measurements revealed a significant dependence of the exit and the downstream flows on Re(h) despite all exit velocity profiles closely approximating a "top-hat" shape. The effect of Re(h) on both the mean and turbulent fields is substantial for Re(h)< 10 000 but becomes weaker with increasing Re(h). The length of the jet's potential core, initial primary-vortex shedding frequency, and far-field rates of decay and spread all depend on Re(h). The local Reynolds number, Re(y0.5)equivalent to 2U(c)y(0.5)/upsilon, where U(c) and y(0.5) are the local centerline velocity and half-width, respectively, are found to scale as Re(y0.5)similar to x(1/2). It is also shown that, for Re(h)>= 1500, self-preserving relations of both the turbulence dissipation rate (epsilon) and smallest scale (eta), i.e., epsilon similar to Re(h)(3)(x/h)(-5/2) and eta similar to Re(h)(-3/4)(x/h)(5/8), become valid for x/h >= 20. (C) 2008 American Institute of Physics.; Mechanics; Physics, Fluids & Plasmas; SCI(E); EI; 29; ARTICLE; 7; 20
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/248837]
专题	工学院
推荐引用方式 GB/T 7714	Deo, Ravinesh C.,Mi, Jianchun,Nathan, Graham J.. The influence of Reynolds number on a plane jet[J]. physics of fluids,2008.
APA	Deo, Ravinesh C.,Mi, Jianchun,&Nathan, Graham J..(2008).The influence of Reynolds number on a plane jet.physics of fluids.
MLA	Deo, Ravinesh C.,et al."The influence of Reynolds number on a plane jet".physics of fluids (2008).