Theoretical Model of Microlayer and Macrolayer Evaporation Considering Heating Surface Temperature Radial Distribution at the Bottom of the Bubble

Based on the dynamic microlayer and macrolayer evaporation models, the mechanisms of single bubble micro and macrolayer evaporation were studied. The nucleate boiling heat transfer and the dynamic characteristics of a single bubble in micro and macrolayers are closely related to the wall temperature. The present work investigates the effects of time and distance on the formation of micro and macrolayer during the growth of a single bubble on a heated horizontal wall. A new complex microlayer and macrolayer model is established. The initial microlayer thickness, dry spot radius, and macrolayer thickness are calculated. The model is compared with experimental data on the evaporation of water and ethanol in the presence of nucleating bubbles. It is found that the previous experimental data are within the range of ±25% of the proposed model, and the predicted data of the model are in good agreement with the experimental data.