Computational fluid dynamics simulation of subcooled flow boiling in vertical rectangular 2-mm narrow channel

This work proposes and discusses a new wall boiling model for a 2-mm narrow rectangular channel with a copper heating surface at atmospheric pressure. The model includes a wall heat flux partitioning model and several sub-models that compute active nucleation site density, bubble departure diameter, and bubble departure frequency. This wall boiling model was developed based on our previous experimental work on narrow channel flow in order to account for the unique thermal-hydraulics that occur under these specific conditions. The model was implemented in CFX code to simulate the subcooled flow boiling in a narrow channel with a two-fluid model; we also considered the onset of nucleate boiling. The new model has been validated by the experimental data. Compared to the default model that had been developed in CFX code, the new model provides better predictions of the distribution of wall temperature in the 2-mm narrow channel