In this paper, the saturated pool boiling heat transfer from a heated circular surface is investigated numerically based on the popular lattice Boltzmann phase-change method. The crucial interfacial phenomena, including the bubble growth, departure, coalescence, and rising under different wall superheats, wettabilities, and heater sizes are studied, and the corresponding heat transfer characteristics within these bubble dynamics are also revealed. The numerical experiments indicate that at low wall superheats the bubble nucleation occurs only at the top of the heated circle. With the increase in the wall superheat, the sides and the bottom of the heated circle also become nucleate sites. As the wall superheats continue to increase, more and more nucleate sites are activated so that the heated circle is wrapped by the vapor film early in the boiling process. And the average heat flux varies periodically with time corresponding to bubble dynamics in nucleation boiling regime. It reaches a steady state of film boiling regime after the stable vapor film is generated from the heated circular. It is also found that hydrophobic surface is conducive to the onset of boiling. However, it leads to a low critical heat flux and incurs film boiling at a lower wall superheat, which is also observed in both experimental and numerical studies. On the other hand, the boiling regimes can undergo the transition from nucleate boiling regime to film boiling regime at the same wall superheat with the increase in the heater size. In addition, under various wall superheats and wettabilities, the bubble departure diameters from the circular surface are smaller than those from the flat surface, while the bubble departure periods from the circular surface are less than those from the flat surface one. Finally, the saturated boiling curves from the circular surface for different wall wettabilities, heater sizes, liquid–vapor density ratios, and heating modes are also achieved.

在本文中，基于流行的晶格 Boltzmann 相变方法，数值研究了加热圆形表面的饱和池沸腾传热。研究了关键的界面现象，包括气泡在不同壁面过热度、润湿性和加热器尺寸下的生长、离开、聚结和上升，并揭示了这些气泡动力学中相应的传热特性。数值实验表明，在低壁过热时，气泡形核仅发生在加热圆的顶部。随着壁面过热度的增加，加热圈的侧面和底部也成为形核点。随着壁面过热度继续增加，越来越多的成核位置被激活，因此加热的圆在沸腾过程的早期被蒸汽膜包裹。并且平均热通量随时间周期性变化，对应于成核沸腾状态下的气泡动力学。加热循环产生稳定的蒸气膜后，它达到膜沸腾状态的稳定状态。还发现疏水表面有利于沸腾的开始。然而，它导致低临界热通量并在下壁过热处引起薄膜沸腾，这在实验和数值研究中也观察到。另一方面，随着加热器尺寸的增加，沸腾状态可以在相同的壁过热度下经历从核沸腾状态到薄膜沸腾状态的转变。此外，在各种壁面过热度和润湿性下，气泡离开圆形表面的直径小于离开平面的直径，而离开圆形表面的气泡离开周期小于离开平面的气泡离开周期。最后，还实现了不同壁润湿性、加热器尺寸、液气密度比和加热模式下圆形表面的饱和沸腾曲线。