Evaluation of the microlayer contribution to bubble growth in horizontal pool boiling with a mechanistic model that considers dynamic contact angle and base expansion

Prediction of Bubble Departure in Forced Convection Boiling with a Mechanistic Model That Considers Dynamic Contact Angle and Base Expansion

“…As explained above, the bubble growth is divided into two periods: the inertia-controlled and the thermal diffusion-controlled growth. For bubble growth during flow boiling the correlations of these two periods that have been proposed by Ding et al for pool boiling are used [27].…”

“…with A and B that are defined in Equation 5. Bubble growth rate in the thermal diffusion controlled growth period is defined as [27] dr b dt td =…”

“…The microlayer evaporation rate, dδ mi dt , is given by considering the heat balance between the latent heat going into the bubble and conductive heat transport through the microlayer with the thickness of δ mi as [27],…”

“…We follow the force balance analysis of Klausner et al [17] and Chen et al [21] for a bubble growing on a superheated heating wall as shown in Figure 6. Based on the conservation of momentum the forces acting on the bubble in parallel (tangential: t) and perpendicular (normal: n) directions of the heating wall are balanced according to F total,n = F growth,n + F drag,n + F surf,n + F b,n + F cp,n + F sl,n (27) F total,t = F growth,t + F drag,t + F surf,t + F b,t + +F growth,b .…”

“…However, it is possible to calculate the value based on the analysis of forces. Ding et al investigated the bubble growth for horizontal pool boiling and considered the dynamic contact angle and dynamic bubble base diameter [27]. They used a mechanistic model based on the force balance method to predict the bubble size and the result of validation against the experimental data was good [27].…”