Numerical Calculation of Bubble Growth in Nucleate Boiling From Inception Through Departure

Abstract

The relative contributions of the fundamental mechanisms accounting for the enhanced heat transfer in nucleate boiling are difficult to quantify analytically or experimentally. A comprehensive model was developed that permits some accurate insights into this problem. An essential feature involved the numerical mapping of the complicated geometry to a plane where the bubble and wall boundaries lie along constant coordinate lines. The results show that microlayer evaporation accounts for 87 percent of the enhanced wall heat transfer during saturated boiling of water at 1 atm and 8.5 K wall superheat. In contrast, enhanced convective effects were essentially nonexistent during growth and minimal following departure. The analysis predicts an extremely nonuniform thermal boundary layer around the bubble, and shows that the wall thermal boundary layer regenerates almost immediately following departure.

A Front-Tracking Method for the Computations of Multiphase Flow

“…Numerical simulations have, until recently, relied on a number of simplifications. Examples of such computation can be found in Lee and Nydahl [68] and Patil and Prusa [85] who assumed that the bubble has a hemispherical shape as it grows. More advanced computations started with Welch [131], who simulated a fully deformable, two-dimensional bubble using moving triangular grids.…”

Physical mechanisms of heat transfer during single bubble nucleate boiling of FC-72 under saturation conditions-I. Experimental investigation

“…bubble formation and departure). Such works typically integrate microphysical models of the contact region dynamics with a meso-scale formulation to directly simulate the heat and mass transfer during a single bubble ebullition event (e.g., in Lee and Nydahl [36], Son et al [37], Liao et al [38], and Genske and Stephan [39]). Contributions from these simulations have been fruitful for exploring the role of the microphysical sub-processes, but most of the simulations are, by necessity, limited to comparisons of bulk quantities with experimental results such as bubble geometry and net heat flux from the surface.…”

Numerical simulation of boiling enhancement on a microstructured surface

“…Computations of bubble growth during nucleate boiling on a horizontal surface were carried out by Lee and Nydahl [11] using a numerical mapping method and Welch [12] using an unstructured moving-grid method. Son et al [13] applied a level-set (LS) method to nucleate boiling by including the effects of contact angle, phase change and the evaporative heat flux from the liquid microlayer.…”