An experimental study to establish a one-on-one correspondence between microlayer dynamics and growth process of single vapor bubble under nucleate pool boiling regime has been presented. The transient evolution of microlayer and the corresponding vapor bubble growth have been simultaneously recorded using a thin film interferometer and one of the gradients-based imaging techniques, namely rainbow schlieren deflectometry. Based on interferometry measurements, the microlayer is observed to undergo three distinct stages. Each of these stages is identified by distinct microlayer structure namely, inverted conical, flattened peripheral region and truncated conical structure during the initial, transitional and diffusion-controlled growth phases of the vapor bubble. Contribution of microlayer towards bubble growth has been established by quantifying the time rate of change of net mass of the superheated fluid entrapped in the microlayer region and the corresponding rate of change of mass of the growing bubble. The analysis showed that the ratio of mass of the superheated fluid in the microlayer region to the mass of the vapor bubble does not exceed a maximum of ∼ 15%. For any given heat flux level, the growing vapor bubble is seen to acquire its maximum size in the transitional regime of the growth process during which the microlayer exhibits a flattened peripheral region. Possible impact of varying heat flux level on microlayer dynamics and movement of the apparent contact line of the vapor bubble has also been discussed. A reasonably good agreement of the experimental data with some of the well-established bubble growth models for initial microlayer thickness has been observed. Based on the experimental results, critical value of empirical parameter ‘C_slope’ (parameter correlating the bubble base radius and the maximum microlayer thickness) for transition from inertia-driven to diffusion dominated growth has been identified to be ∼ 0.0042.

提出了在核池沸腾状态下建立微层动力学与单个蒸汽泡生长过程之间的一对一对应关系的实验研究。使用薄膜干涉仪和基于梯度的成像技术之一，即彩虹纹影偏转法，同时记录了微层的瞬态演变和相应的蒸汽泡生长。根据干涉测量，观察到微层经历三个不同的阶段。这些阶段中的每一个都由不同的微层结构识别，即在蒸汽泡的初始、过渡和扩散控制生长阶段期间的倒锥形、扁平外围​​区域和截锥形结构。微层对气泡生长的贡献已经通过量化微层区域中捕获的过热流体的净质量的时间变化率和相应的生长气泡的质量变化率来确定。分析表明，微层区域过热流体的质量与蒸汽泡的质量之比最大不超过～15%。对于任何给定的热通量水平，可以看到在微层呈现平坦外围区域的生长过程的过渡状态中，生长的蒸汽泡获得其最大尺寸。还讨论了变化的热通量水平对微层动力学和蒸汽泡明显接触线的运动的可能影响。已经观察到实验数据与一些完善的初始微层厚度的气泡生长模型的相当好的一致性。根据实验结果，经验参数的临界值 'C_斜率'（与气泡底部半径和最大微层厚度相关的参数）从惯性驱动到扩散主导生长的转变已被确定为 ~ 0.0042。