Heat transfer analysis of the Marangoni effect around a surface gas bubble in a microchannel

An in-depth numerical investigation was conducted to explore the impact of the Marangoni effect around a surface bubble on the heat transfer performance in a microchannel. By comparing the average Nusselt numbers of the system in scenarios with or without bubbles on the lower wall of a microchannel, as well as the presence or absence of the Marangoni effect around bubbles, the fluid's heat transfer performance in the microchannel under different Reynolds number (Re) and temperature difference (ΔT) was investigated. It was found that surface bubbles significantly enhance the fluid's heat transfer efficiency. When the Marangoni effect is present, the heat transfer efficiency in the microchannel is considerably improved compared to when bubbles do not exhibit the Marangoni effect. This enhancement becomes more pronounced as the temperature difference increases and diminishes with rising Re. Most notably, at a constant ΔT, the heat transfer efficiency exhibited its maximum growth rate (τ) when Re fell in the scale of 5–12. Our research illuminates crucial understanding of how the Marangoni effect of bubbles enhances heat transfer within confined fluid systems, providing valuable guidance for determining suitable parameters, such as temperature difference and Reynolds number, in applications like microchannel heat exchangers and related technologies.