Turbulent water flow in a channel at Reτ = 400 laden with 0.25 mm diameter air-bubbles clustered near the wall
Turbulent water flow in a channel at Reτ = 400 laden with 0.25 mm diameter air-bubbles clustered near the wall
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DOI：
10.1063/1.4984003
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发表时间：
2017-06
影响因子：
4.6
通讯作者：
D. Lakehal;D. Métrailler;S. Reboux
中科院分区：
文献类型：
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作者：
D. Lakehal;D. Métrailler;S. Reboux
本文给出了Reτ=400时槽道内湍流流动的直接数值模拟结果，其中直径为0.25 mm的气泡在壁面附近聚集(在y+α20时，∼的最大含气率=8%)。使用CFD/CMFD代码Transat中的Level Set方法完全解决了气泡问题。流体性质(空气和水)保持真实，包括密度、粘度和表面张力系数。这项工作的目的是了解气泡对近壁湍流的影响，为对流壁面沸腾流动的研究铺平道路。通过对湍流统计的深入分析，研究了气泡与水流的相互作用。近壁流动总体上受到气泡的影响，气泡在离开壁面之前的早期阶段起到了粗糙元素的作用。壁面附近的气泡动力学明显改变了平均轮廓，这与类似研究的结果形成了一定的对比。
This paper presents Direct Numerical Simulation (DNS) results of a turbulent water flow in a channel at Reτ = 400 laden with 0.25 mm diameter air bubbles clustered near the wall (maximum void fraction of α = 8% at y+ ∼ 20). The bubbles were fully resolved using the level set approach built within the CFD/CMFD code TransAT. The fluid properties (air and water) were kept real, including density, viscosity, and surface tension coefficient. The aim of this work is to understand the effects of the bubbles on near-wall turbulence, paving the way towards convective wall-boiling flow studies. The interactions between the gas bubbles and the water stream were studied through an in-depth analysis of the turbulence statistics. The near-wall flow is overall affected by the bubbles, which act like roughness elements during the early phase, prior to their departure from the wall. The average profiles are clearly altered by the bubbles dynamics near the wall, which somewhat contrasts with the findings from similar studi...