Assessment of Models for Onset of Flow Instability Experimental Data in Narrow Rectangular Channel

Assessment of models for Onset of Significant Void and Onset of Flow Instability was carried out against narrow rectangular channel (1 000 mm×25 mm×2 mm) experimental data in the condition of:P=1~15 MPa,G=500~2 000 kg/(m².s),△T_sub,in=20~100℃,q=40~1 000 kW/m².The results showed the correlations of Saha-Zuber,Levy and Bowring for OSV and the correlations of W&F,Lee&Bankoff and Kennedy for OFI predicted the experimental results within ±20%,but predicted OFI obviously lower at low heat flux and higher results at high heat flux.A new purely empirical correlation was developed by comparing the heat flux leading to OFI with that leading to saturation:qOFI=1.95q_sat^0.87.The deviation is within ±15%.It is also suitable for other types of channels and parameters.