Numerical simulation of 3D turbulent bend flow based on unstructured grids
Numerical simulation of 3D turbulent bend flow based on unstructured grids
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基于非结构网格的3D湍流弯曲流数值模拟
DOI：
10.18280/ijht.360334
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发表时间：
2018-09
影响因子：
0.9
通讯作者：
Chunguang Li
中科院分区：
文献类型：
--
作者：
Suiju Lv;Fen Gao;Chunguang Li
收稿日期: 2018年2月9日 接受日期: 2018年6月12日 本文针对黄河沙坡头河段的连续弯道，对连续弯道的水位变化、平面流场变化、纵向流变化和二次流进行了探讨。具体而言，采用基于非结构化网格的有限体积法对三维湍流数学模型进行离散化，建立非结构化网格下的数值求解方程，并利用非结构化非交错网格采用SIMPLE算法对模型进行求解。然后，将计算区域划分为三角形网格，对弯曲处网格进行加密，并采用等距分层法将垂直方向划分为多层。模拟结果与测量值吻合良好。凸岸的水位一般低于凹岸。第一个弯道凹岸水位比凸岸高0.02m；第二弯凸岸水位较凸岸高出0.04m。连续弯道中主流流速偏向凹岸。随着第二个弯道中心角的增大，主流逐渐向凸岸移动，到达弯道尖端的岸边。此外，凸岸上的表底涡日益明显和强烈，两弯道之间的短过渡区受第一弯道高流量区的影响明显，入口凸岸和出口凸岸附近发生冲刷。结果证明，该模型能够准确模拟复杂边界天然河流的3D弯道水流；除平面螺旋流外，该模型还可以模拟主流流量的截面分布。
Received: 9 February 2018 Accepted: 12 June 2018 Focusing on the continuous bends in Shapotou section of the Yellow River, this paper probes into the water level variation, planar flow field variation, longitudinal flow variation and secondary flow in the continuous bends. Specifically, a mathematical model for 3D turbulent flow was discretized by the finite-volume method based on unstructured grids, a numerical solution equation was set up under the unstructured grids, and the model was solved by the SIMPLE algorithm using unstructured non-staggered grids. Then, the calculation area was meshed into triangular grids, the grids were densified for the bends, and the vertical direction was divided into multiple layers by the equidistant layering method. The simulated results agree well with the measured value. The convex bank generally had a lower water level than the concave bank. In the first bend, the water level of the concave bank was 0.02m higher than that of the convex bank; in the second bend, the water level of the convex bank was 0.04m higher than the convex bank. The mainstream flow rate was biased towards the concave bank in the continuous bends. With the increase of the central angle in the second bend, the mainstream gradually moved to the convex bank and reached the bank at the tip of the bend. Besides, the surface-bottom vortex on the convex bank became increasingly obvious and intense, the short transition area between the two bends was significantly affected by the high flow rate area of the first bend, and scouring occurred near the convex bank at the inlet and the convex bank at the outlet. These results prove that the proposed model can accurately simulate the 3D bend water flow of natural rivers with complex boundaries; apart from planar spiral flow, the proposed model could simulate the sectional distribution of mainstream flow rate.
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DOI：
--
发表时间：
2013
期刊：
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影响因子：
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作者：
Lv Sui-j
通讯作者：
Lv Sui-j
DOI：
--
发表时间：
2003
期刊：
Advances in Water Science
影响因子：
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DOI：
10.1016/j.cnsns.2006.01.015
发表时间：
2007-10
影响因子：
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通讯作者：
F. Schmitt
DOI：
--
发表时间：
2011
期刊：
Chinese Journal of Hydrodynamics
影响因子：
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作者：
Y. Jun
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Y. Jun
影响因子：
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作者：
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通讯作者：
L. Pinto;A. Fortunato;Yinglong J. Zhang;Anabela Oliveira;F. Sancho