Robustness and accuracy of SPH formulations for viscous flow
Robustness and accuracy of SPH formulations for viscous flow
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DOI：
10.1002/fld.1927
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发表时间：
2009-08-10
影响因子：
1.8
通讯作者：
Lastiwka, Martin
中科院分区：
文献类型：
--
作者：
Basa, Mihai;Quinlan, Nathan J.;Lastiwka, Martin
光滑颗粒流体力学（SPH）中粘性应力项的建模方法有很多。在这项工作中，现有的方法进行了系统的研究，并使用泊泽维尔通道和盖驱动腔测试案例对一系列雷诺数进行了评估。Morris et al.和Cleary提出的基于有限差分和SPH近似组合的两种方法获得了最好的结果。用标准SPH估计高值函数的梯度是不准确的。在计算梯度之前减少函数（特别是压力）值的方法减少了这种不准确性，并被证明可以提高性能。在其他作品中也报道了泊泽维尔沟道流动的不稳定模式，并提出了定性解释。边界实现的选择对流动启动时的瞬态速度分布有显著影响。使用至少线性外推的壁内速度被证明比镜像速度更可取。对于大多数方法，对内核的一致性修正也会显著提高准确性和稳定性，尽管并非所有情况都如此。版权所有(C) 2008约翰威利父子有限公司
Numerous methods are available for the modelling of viscous stress terms in smoothed particle hydrodynamics (SPH). In this work, the existing methods are investigated systematically and evaluated for a range of Reynolds numbers using Poiseuille channel and lid-driven cavity test cases. The best results are obtained using two methods based on combinations of finite difference and SPH approximations, due to Morris et al. and Cleary. Gradients of high-valued functions are shown to be inaccurately estimated with standard SPH. A method that reduces the value of functions (in particular, pressure) before calculating the gradients reduces this inaccuracy and is shown to improve performance. A mode of instability in Poiseuille channel flows, also reported in other works, is examined and a qualitative explanation is proposed. The choice of boundary implementation is shown to have a significant effect on transient velocity profiles in start-up of the flow. The use of at least linear extrapolation for in-wall velocities is shown to be preferable to mirroring of velocities. Consistency corrections to the kernel are also found to result in significant accuracy and stability improvements with most methods, though not in all cases. Copyright (C) 2008 John Wiley & Sons, Ltd.