Effect of exit Reynolds number on a turbulent round jet

作者：Cheng Du, Minyi Xu, Jianchun Mi · 发表于：Acta Physica Sinica · 年份：2010 · DOI：10.7498/aps.59.6331 · 被引用次数：13 · 研究领域：Aerodynamics and Acoustics in Jet Flows、Fluid Dynamics and Turbulent Flows、Heat Transfer Mechanisms

The present study systematically investigates by experiment the influence of Reynolds number (Re) on a turbulent jet issuing from a smoothly-contracting round nozzle. Measurements were performed for seven Reynolds numbers varying from Re = 4,050 to Re = 20,100 using single hot-wire anemometry and over an axial distance of 30 nozzle exit diameters. Although all the exit velocity profiles are of "top-hat" shape, these measurements reveal significant dependence on Re of the exit and downstream flows. The effect of Re on both the mean and turbulent fields is substantial for Re ＜ 10,000 and becomes weak beyond Re = 10,000. The length of the jet’s potential core and the far-field rates of decay and spread all depend significantly on Re.