Review: Surface orientation effects on Pool-boiling with plain and enhanced surfaces

Abstract

A Pool Boiling (PB) is crucial to safe and efficient operations in various applications such as thermoelectric power conversion, refrigeration, electronics, transportation, microfluidics, biomedical engineering, metallurgical industry, and space exploration. However, the poor counter-current flows near the heated surface limit the maximum PB cooling efficiency via a premature surface dryout, i.e., poor Critical Heat Flux (CHF) and Heat Transfer Coefficient (HTC). The two-phase flow substantially changes as the surface orientation deviates from the upward facing, leading to the CHF and HTC changes. This paper reviews the effects of surface orientation on the two-phase flows and their PB performance using various coolants for plain and engineered surfaces. This review includes both the experimental and theoretical approaches to understand HTC and CHF, including tailored two-phase flow for enhanced HTC and CHF. This review also discusses future research directions for engineered surface under different surface orientation.