Predictions of solute transport in a compound channel using turbulence models
Predictions of solute transport in a compound channel using turbulence models
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DOI：
10.1080/00221680309499970
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发表时间：
2003-05
影响因子：
2.3
通讯作者：
K. Shiono;C. Scott;D. Kearney
中科院分区：
文献类型：
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作者：
K. Shiono;C. Scott;D. Kearney
采用两种湍流模型对非对称复合流道中的溶质分布进行了预测。数值模型的结果与最近用激光多普勒风速仪(LDA)和激光诱导荧光(LIF)在小型实验室水槽中获得的湍流数据进行了比较。利用k-S模型和代数应力模型对水面附近不同喷射点的溶质通量和雷诺通量分布进行了预测，以识别不同的混合机制。实验数据表明，代数应力模型能很好地预测滩地上溶质的偏态分布，而k-ε模型则不能很好地预测。通过二次流和旋涡扩散系数的变化，分析了偏斜分布的原因。用实验数据讨论了预测的涡粘性和扩散系数以及湍流施密特数。结果表明，即使涡动粘性没有被任何特定的模型正确计算，通过调整湍流施密特数也能很好地预测溶质浓度分布。二次流对沿流道剪切层峰值浓度的影响也得到了证实。
Prediction of solute distributions in an asymmetric compound channel is carried out using two turbulence models. Results of the numerical models are compared with turbulence data recently obtained using laser Doppler anemometer (LDA) and laser induced fluorescence (LIF) in a small laboratory flume. The predicted distributions of solute and Reynolds flux using a k-s model and an algebraic stress model for various injection points near the water surface are used to identify different mixing mechanisms. A skewed distribution of solute on the floodplain observed in the experimental data is well predicted by the algebraic stress model but not by the k-ε model. The cause of the skewed distribution is examined through the variations of secondary flow and eddy diffusivity. The predicted eddy viscosity and diffusivity and the turbulent Schmidt number are discussed with the experimental data. As a result, solute concentration distribution can be well predicted by adjusting the turbulent Schmidt number even if the eddy viscosity was not correctly calculated by any particular model. An effect of secondary flow on peak concentration in the shear layer along the channel is also demonstrated.