Simulation of Nucleate Boiling With Interfacial Temperature Gradients and Sharp Interface

Abstract

Effective heat transfer techniques benefit the development of nuclear and fossil fuel powered steam generators, high power electronic devices, and industrial refrigeration systems. Boiling dissipates large heat fluxes while keeping a low and a constant surface temperature. However, studies of the fluid behavior surrounding the bubble and the heat transfer near the contact-line are scare due to difficulties of flow visualization, chaotic conditions, and small length scales. The preset study shows the simulation of bubble growth over a heated surface from conception to departure. The computation of mass transfer with interfacial temperature gradients leads to proper bubble growth rates. Models to include the interface sharpness uncover the dynamic and thermal interaction between the interface and the fluid. Results indicate that the nucleation of a bubble (in water at 1 atm with 6.2 K wall superheat) has an influence region of 2Db (where Db is the departure bubble diameter). In addition, results reveal a thin thermal film near the interface that increases the heat transfer at the contact-line region. Numerical bubble growth rates compare well with experimental data on single bubble nucleation.