Optimization of flow boiling correlations for heat transfer and flow pattern inside microchannels

Abstract

This research proposal is part of a number of projects involving the investigation of two-phase flow and flows boiling inside microchannels (equivalent diameter smaller than 3 mm) currently being implemented by the Group of Heat and Mass Transfer from the Department of Mechanical Engineering at EESC-USP. An extensive database of experimental convective boiling in microchannels has been produced in this group over the past four years which has the potential to generate new correlations and predictive models for heat transfer, critical heat flux, flow pattern maps, pressure drop, and other important parameters in two-phase flows. Since the available models in the literature still have considerable prediction errors and they can be applied only to a restricted experimental range, a great contribution can be performed using this database to generate new models. Due to the complexity of the physical mechanisms associated with flow boiling, the use of semi-empirical correlations is the method most successful Thus, this project has the objective to organize and centralize a huge database for flow boiling in microchannels, using experimental data obtained in this research group as well as in other laboratories to optimize correlations to predict the transfer coefficient heat, critical heat flux and flow pattern transitions. It is expected that new correlations with better performance will be obtained in this work.(AU)