SPH modelling of depth-limited turbulent open channel flows over rough boundaries.
SPH modelling of depth-limited turbulent open channel flows over rough boundaries.
复制标题
深度限制的湍流开放通道的SPH建模在粗糙的边界上流动。
DOI：
10.1002/fld.4248
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发表时间：
2017-01-10
影响因子：
1.8
通讯作者：
Shao S
中科院分区：
文献类型：
--
作者：
Kazemi E;Nichols A;Tait S;Shao S
建立了一个基于光滑质点流体力学方法的数值模型，用于模拟水力粗糙河床上的有限深湍流明渠水流。求解了二维拉格朗日形式的Navier-Stokes方程，其中基于床面附近的有效粗糙度区域采用基于阻力的公式来考虑床球的粗糙度效应，并采用改进的亚颗粒尺度模型来考虑湍流的影响。亚粒子尺度模式基于混合长度假设而不是标准的Smagorinsky方法来计算涡粘性。还提出了一种稳健的进/出流边界技术，以在流动特性未知的进出口边界处实现稳定的均匀流动条件。应用该模型模拟了规则球体组成的粗糙河床上的均匀明渠水流，并用实验流速数据进行了验证。为了研究床面粗糙度对不同水流条件的影响，对12个不同河床坡度和均匀水深的试验数据进行了模拟，计算结果与水流速度和湍流剪应力的试验结果吻合较好。这表明，为了正确地模拟粗糙床边界上的湍流机制，必须同时考虑粗糙度效应和流动湍流，而本文提出的光滑颗粒流体动力学模型成功地实现了这一点。#2016 John Wiley&Sons Ltd.出版的《国际流体数值方法杂志》
A numerical model based on the smoothed particle hydrodynamics method is developed to simulate depth‐limited turbulent open channel flows over hydraulically rough beds. The 2D Lagrangian form of the Navier–Stokes equations is solved, in which a drag‐based formulation is used based on an effective roughness zone near the bed to account for the roughness effect of bed spheres and an improved sub‐particle‐scale model is applied to account for the effect of turbulence. The sub‐particle‐scale model is constructed based on the mixing‐length assumption rather than the standard Smagorinsky approach to compute the eddy‐viscosity. A robust in/out‐flow boundary technique is also proposed to achieve stable uniform flow conditions at the inlet and outlet boundaries where the flow characteristics are unknown. The model is applied to simulate uniform open channel flows over a rough bed composed of regular spheres and validated by experimental velocity data. To investigate the influence of the bed roughness on different flow conditions, data from 12 experimental tests with different bed slopes and uniform water depths are simulated, and a good agreement has been observed between the model and experimental results of the streamwise velocity and turbulent shear stress. This shows that both the roughness effect and flow turbulence should be addressed in order to simulate the correct mechanisms of turbulent flow over a rough bed boundary and that the presented smoothed particle hydrodynamics model accomplishes this successfully. © 2016 The Authors International Journal for Numerical Methods in Fluids Published by John Wiley & Sons Ltd