Suitability Evaluation of Bubble Departure Diameter and Frequency Models for the Simulation of Subcooled Confined Jet Impingement Boiling

Accurate estimation of multiphase turbulence, interphase momentum exchange and bubble dynamics parameters such as bubble departure diameter and frequency is critical for a realistic simulation of flow boiling heat transfer. While there are experimental and mechanistic models available for the estimation of these parameters for rather specific geometric configurations, fluids and operating conditions, there is no specific comprehensive model for jet impingement boiling. Nor is there a consensus on a generalized model, particularly for the ebullition parameters, that could be extended to jet impingement boiling. Hence, a problem-based evaluation of the available models to conform to experimental data is often required. In the present work, a rigorous study is carried out to ascertain the suitability of different bubble departure diameter and departure frequency models for the simulation of confined and submerged, subcooled jet impingement boiling. The choice of ebullition models considered encompass both pool boiling as well as flow boiling based models, developed from both experimental as well as mechanistic approaches. The suitability of the models are evaluated by comparison of the predicted local and surface averaged heat transfer characteristics against experimental boiling data from the present research as well as that available in the literature. The computational simulations are carried out using the finite volume computational solver ANSYS FLUENT 14.5, with necessary customized functions for boiling parameters formulated and integrated into the solver.