Numerical study of the effect of forced convective flow on dropwise condensation by thermal LBM simulation
Numerical study of the effect of forced convective flow on dropwise condensation by thermal LBM simulation
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DOI：
10.1051/matecconf/201824001040
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Shaofei Zheng;F. Eimann;T. Fieback;U. Gross
中科院分区：
文献类型：
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作者：
Shaofei Zheng;F. Eimann;T. Fieback;U. Gross
采用基于Shan-Chen伪势LB模型的二维混合热晶格玻尔兹曼（LB）模型，对冷点上强制对流对水滴凝结的增强机理进行了数值研究。在验证了目前的LB模型后，模拟了冷点上的液滴冷凝作为成核区域。证明了单个冷凝液滴生长的著名幂律。最后，在恒定接触半径（CCR）模式下进行了考虑对流流和不考虑对流流的水滴凝结模拟。利用CCR模型，还可以研究接触角的影响。流线场的结果表明，强制对流流动使液滴内部流动和主流流动变得复杂。来自主流的拖拽力改变了液滴内部两个对称涡的大小。在三相接触线处，由于冷凝而产生的吸力效应对通道流动也有很强的影响。相比之下，叠加流的换热强化作用就不值一提了。本文研究了强迫对流条件下水滴凝结的机理。
The enhancement mechanism of forced convective flow on dropwise condensation over a cold spot is numerically investigated by two-dimensional hybrid thermal lattice Boltzmann (LB) model based on the Shan-Chen pseudopotential LB model. After validating the present LB model, dropwise condensation over a cold spot as the nucleation region is simulated. The well-known power law for the growth of a single condensing droplet is demonstrated. Finally, the simulation of dropwise condensation considering the convection flow or not is carried out in the constant contact radius (CCR) mode. Using the CCR model, the effect of contact angle can be also investigated. The result of streamline field indicates that the forced convectional flow complicates the internal flow of droplet and main flow. The dragging force from main flow changes the size of two symmetric vortices inside the droplet. And the channel flow is also strongly influenced by the suction effect caused by condensation at the three phase contact line. By comparison, the heat transfer enhancement of the superimposed flow is not worth mentioning. The present study illustrates the mechanisms of dropwise condensation under forced convectional flow.