Evaluation of existing physical models on critical flow based on experiment with a nozzle

A critical flow experiment of water was carried out at steadystate in a nozzle with diameter of 1.41 mm, covering the ranges of inlet pressure of 0.4-22 MPa, inlet temperature of 40-371 ℃ and inlet quality of －3.5-0.98. The flow doesn’t exhibit choking behavior at the inlet subcooling larger than a certain value. In low subcooling and low quality region thermal non-equilibrium between two phases has appreciable effect on the critical flow rate, especially at lower pressure. The experimental data were compared with the predictions of several models, including the Homogeneous equilibrium model, the Moody model, the Henry-Fauske model, the Burnell model and the Bernoulli correlation, showing their applicability for different conditions.