Numerical study on the critical heat flux based on the two-phase multi-scale interface model using OpenFOAM

For the analysis of two-phase phenomena, this work addresses the implementation of the advanced multi-scale interface model of Tentner et al. (2006) into OpenFOAM-7 code, and its assessment for flow boiling in vertical pipes. The model considers the concentration and shape of the interfacial region, as well as the interphase interactions. Two-phase boiling-flow data were used to methodically evaluate this model and its overall propensity to predict the critical heat flux (CHF) was then assessed. Departure from nucleate boiling (DNB) was predicted based on a surface temperature rise, which served as the criterion. The impacts of exit quality, pressure and mass flow velocity on DNB were also addressed. The mean percentage discrepancy found between CHF lookup table and simulated results was 3%, indicating a satisfactory level of agreement. Findings indicate that the implemented two-phase multi-scale interface model in OpenFOAM-7 tool could be utilized in forecasting boiling flow involving flow topology transitions and adequately predict CHF.