Convective heat transfer with condensation in crossflow of a circular cylinder: Experiments and simulations

Abstract

Forced convection heat transfer has been widely studied but not with the inclusion of condensation phenomenon particularly in crossflow of a cylinder. In this study, the convective heat transfer with moisture condensation of the air that is relevant for food thawing applications with the airflow around a circular cylinder was investigated. Experiments were carried out that represents food air-thawing conditions such as the Re number within a subcritical range, and the relative humidity of air being varied. Heat flux was measured at different angles around the cylinder to characterize the local heat transfer. A three-dimensional CFD modeling was subsequently carried out with the appropriate choice of turbulence model, and the condensation with the presence of non-condensable gasses. The simulation results were well correlated with the experimental data. The heat transfer rate on the leeward side is enhanced with the development of the detached vortex at higher Re number; hence, changing it within a certain range is an effective method to improve the uniformity of convective condensation heat transfer. An increase in the relative humidity was found to enhance the average convective condensation heat transfer. An empirical correlation that predicts the overall heat transfer was developed adopting Nu, Re, and Pr numbers.