Turbulent prandtl number in a circular jet
Turbulent prandtl number in a circular jet
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DOI：
10.1016/0017-9310(90)90102-z
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发表时间：
1990-02
影响因子：
5.2
通讯作者：
L. Chua;R. Antonia
中科院分区：
文献类型：
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作者：
L. Chua;R. Antonia
雷诺剪切应力和热通量分布的测量在一个加热的圆形射流到静止的空气中的一些流向站表明，该流动是近似自保持在x d= 15。与使用90° X探头进行的测量相比，使用120° X探头进行的测量与通过积分平均动量和平均焓方程获得的计算结果更接近一致。湍流普朗特数在射流边缘附近增加，但在轴线和射流半半径之间的区域内，它近似为常数（0.81±0.05）。这个数值与So和Hwang（ZAMP 37，624-631（1986））为非等温圆形射流的相似解所选择的数值是合理一致的。有人建议，早期实现自我保护，在目前的流动可能是由于在射流出口处的层流条件。
Measurements of the Reynolds shear stress and heat flux distributions at a number of streamwise stations in a heated circular jet into still air indicate that the flow is approximately self-preserving at x d= 15. Measurements made with a 120° X-probe are in closer agreement with calculations obtained by integrating the mean momentum and mean enthalpy equations than measurements made with a 90° X-probe. The turbulent Prandtl number increases near the edge of the jet but, in a region between the axis and the jet half-radius, it is approximately constant (0.81±0.05). This numerical value is in reasonable agreement with that selected by So and Hwang (ZAMP37, 624–631 (1986)) for similarity solutions of non-isothermal round jets. It is suggested that the early attainment of self-preservation in the present flow may be due to the laminar conditions at the jet exit.