Journal of Hydraulic Research ( IF 2.3 ) Pub Date : 2021-03-24 , DOI: 10.1080/00221686.2020.1862322 Ebenezer E. Essel 1 , Shawn P. Clark 2 , Karen Dow 3 , Mark F. Tachie 4
This paper presents both experimental measurements and three-dimensional (3D) numerical simulations of turbulent flow in open channels with simulated partial ice-covers. The experiments were conducted with a particle image velocimetry system while the simulations were performed with five eddy-viscosity and second-moment closure turbulence models. Four coverage ratios based on the channel width were examined in each case: a reference fully open channel and 25%, 50% and 75% partially covered channels. The results showed that the influence of the partial ice-covers and secondary currents near the sidewall dramatically altered the distributions of the mean velocity, Reynolds stresses and turbulence production across the channel. Based on the 3D simulations, it was shown that the modifications to the turbulence quantities were largely influenced by strong counter-rotating secondary circulations in the core of the partially covered channels and eight smaller secondary cells at the corners. The core secondary circulations interact with adjacent corner cells to form a dynamic link between the open water and ice-covered sections of the channel.
中文翻译:
具有模拟部分冰盖的三维明渠的实验和数值研究
本文介绍了带有模拟部分冰盖的明渠中湍流的实验测量和三维 (3D) 数值模拟。实验是用粒子图像测速系统进行的,而模拟是用五个涡粘性和二阶矩闭合湍流模型进行的。在每种情况下检查了基于通道宽度的四种覆盖率:参考完全开放通道和 25%、50% 和 75% 部分覆盖的通道。结果表明,部分冰盖和靠近侧壁的二次流的影响显着改变了通道的平均速度、雷诺应力和湍流产生的分布。基于 3D 模拟,结果表明,湍流量的改变在很大程度上受到部分覆盖的通道核心和角落处八个较小的二次单元的强烈反向旋转二次循环的影响。核心二级循环与相邻的角单元相互作用,在通道的开阔水域和冰覆盖部分之间形成动态联系。