Numerical Heat Transfer, Part A: Applications ( IF 2 ) Pub Date : 2021-07-28 , DOI: 10.1080/10407782.2021.1947093 Yuhao Lin 1 , Yang Luo 1 , Wei Li 1 , Ekaterina Sokolova 2 , Yanlong Cao 3 , Wally J. Minkowycz 4
Abstract
The diverging microchannel has a gradually expanding cross-section area along the flow direction that can reduce flow instability and hence partial dry out. Utilizing the VOF method, Hardt and Wondra phase change model, and dynamic refined mesh scheme within a self-developed OpenFOAM solver, the vapor slug bubble’s growth inside diverging and uniform microchannels are investigated. The effects of mass flux, heat flux, and diverging gradient on the bubble behavior and flow instability are discussed. The bubble growth caused the upstream flow to slow down and downstream flow to speed up, which lead to the pressure drop oscillation. The velocity of the flow is higher in the diverging microchannel cases, either upstream or downstream the vapor slug bubble. These indicate the expanding cross-section area can promote the bubble to move toward the downstream outlet thus mitigate the blockage of the channel and flow instability.
- HIGHLIGHT
The effects of slug bubble growth on flow and heat transfer are revealed through numerical investigation.
The bubble growth process varied in the diverging and uniform microchannels.
The diverging channel can help mitigate the blockage of the microchannel and flow instability.
中文翻译:
发散微通道流动沸腾过程中段塞气泡生长的数值研究
摘要
发散的微通道沿流动方向具有逐渐扩大的横截面面积,可以减少流动的不稳定性,从而减少部分干涸。利用VOF方法、Hardt和Wondra相变模型以及自主开发的OpenFOAM求解器中的动态细化网格方案,研究了发散均匀微通道内蒸汽段塞气泡的生长。讨论了质量通量、热通量和发散梯度对气泡行为和流动不稳定性的影响。气泡的增长导致上游流速减慢,下游流速加快,从而导致压降振荡。在发散的微通道情况下,无论是在蒸汽段塞气泡的上游还是下游,流速都较高。
- 强调
通过数值研究揭示了段塞气泡生长对流动和传热的影响。
气泡生长过程在发散和均匀的微通道中变化。
发散通道可以帮助减轻微通道的堵塞和流动的不稳定性。