Prediction of nucleate boiling heat transfer in high-gravity fields

Prediction of nucleate boiling heat transfer in high-gravity fields is essential to its application in some rotating devices. It is still not known how to predict it in practical, especially for onset of nucleate boiling (ONB) and heat transfer coefficient (HTC). For this purpose, a theoretical model of ONB in hypergravity is developed first time, incorporating the critical effects of hydrostatic pressure and natural convection. Based on the model, an explicit correlation is proposed. The effects of hypergravity on ONB are investigated, revealing the boiling is difficult in high-gravity fields due to the enhanced natural convection, induced local subcooling near the heating surface, and reduced active nucleation microcavities. Subsequently, an appropriate correlation is selected to calculate HTCs of fully developed boiling in hypergravity, showing a mean deviation of 11.9 % compared with the 491 datapoints collected over a hypergravity range of 1.9 g–400 g. Finally, the boiling curves of water under different levels of hypergravity are constructed. The results show that the hypergravity enhances the heat transfer before the fully developed boiling, but delays the ONB, especially under low system pressure. Generally, the validated and proposed correlations provide researchers a reliable and user-friendly mathematical tool to conduct a preliminary design of the nucleate boiling heat transfer in rotating devices.