On the bubble departure diameter and release frequency based on numerical simulation results

Heterogeneous boiling on a horizontal plate in stagnant and slowly flowing fluid is simulated using the lattice Boltzmann approach. The bubble departure diameter and release frequency are determined from the simulation results. It is found that the bubble departure diameter is proportional to g(-1/2) in a stagnant fluid and the release frequency scales with g(3/4), where g is the gravitational acceleration. Simulation results show no dependence between the bubble departure diameter and the static contact angle, but the bubble release frequency increases exponentially with the latter. Considering forced boiling, exponential relation is observed between the bubble departure diameter and the flow driving pressure gradient. (C) 2008 Elsevier Ltd. All rights reserved.