Numerical investigation of flow instability in a low-pressure subcooled boiling channel

A three-dimensional two-fluid model to predict pressure drop and void fraction in a subcooled boiling flow at low pressure is adopted to investigate the flow instability due to the presence of two-phase flow in a heated channel. Good agreement on the overall pressure drop against experimental measurements was achieved. Predicted results of void fraction provided useful information towards a more fundamental understanding of the occurrence of incipient boiling, onset of significant voiding and onset of flow instability. The phenomenon of boiling onset oscillations observed in the experiment was also revealed through the use of the present two-fluid model.