Predicting Free-Surface Vortices with Single-Phase Simulations
Predicting Free-Surface Vortices with Single-Phase Simulations
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DOI：
10.1080/19942060.2014.11015507
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发表时间：
2014-01
影响因子：
6.1
通讯作者：
A. Škerlavaj;L. Skerget;J. Ravnik;A. Lipej
中科院分区：
文献类型：
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作者：
A. Škerlavaj;L. Skerget;J. Ravnik;A. Lipej
摘要本文采用单相计算流体动力学方法对自由表面涡进行了模拟。模拟的目的是确定合适的湍流模型的自由表面涡，这可能会被应用到各种工程系统中的流动模拟。采用非定常单相流数值模拟方法，对实验室模型中的自由表面涡进行了数值模拟。涡周向速度，涡核内的向下速度和自由表面涡气核的预测长度与现有的测量进行了比较。对于两方程湍流模型，结果表明了曲率修正（CC）的重要性。分析了时间步长的影响和平流方案的选择。对于试验情况，确定了流动的非定常性不足以保证尺度自适应模拟（SAS）湍流模型的正确行为。使用CC选项时，剪切-应力-传输（SST-CC）湍流模型和SAS-CC湍流模型均可用于此类预测;然而，发现SAS-CC模型更可靠。单相模拟成功地预测了短气芯涡流的气芯长度。然而，对于长芯，长度被低估。
Abstract In this article, single-phase, computational-fluid-dynamics simulations of free-surface vortices are presented. The purpose of the simulations is to determine the appropriate turbulence model for free-surface vortices, which could later be applied to simulations of flow in various engineering systems. The water flow in the laboratory model of a free-surface vortex was numerically simulated by unsteady single-phase computations. The vortex circumferential velocity, the downward velocity inside the vortex core and the predicted length of the free-surface vortex gas core were compared with available measurements. For the two-equation turbulence models, the results indicated the importance of the curvature correction (CC). The effect of the time-step size and the choice of the advection scheme were analyzed. For the tested case, it was determined that the unsteadiness of the flow was insufficient for the correct behavior of the scale-adaptive simulation (SAS) turbulence model. With the CC option, the shear-stress-transport (SST-CC) turbulence model and the SAS-CC turbulence model can both be used for such predictions; however, the SAS-CC model was found to be more reliable. Single-phase simulations successfully predicted the gas-core length for vortices with a short gas core. However, for long cores, the length was underpredicted.