Critical Heat Flux and Boiling Heat Transfer to Water in a 3-mm-Diameter Horizontal Tube

Boiling of the coolant in an engine, by design or by circumstance, is limited by the critical heat flux phenomenon. As a first step in providing relevant engine design information, this study experimentally addressed both rate of boiling heat transfer and conditions at the critical point of water in a horizontal tube of 2.98-mm inside diameter and 0.9144-m heated length. Experiments were performed at a system pressure of 203 kPa, mass fluxes of 50-200 kg/m²s, and inlet temperatures from ambient to 80°C. Experimental results and comparisons with predictive correlations are presented.