Validation of interfacial area concentartion approaches for prediction of gas-dispersed condensing flows

Accurate predictions of void fraction and interfacial area concentration (IAC) are important in the validation of the condensation phase change term for gas-dispersed condensing flows. Traditionally static correlations have been used to predict IAC for different flow conditions and flow regimes. The interfacial area transport equation (IATE) can dynamically predict IAC and is increasingly being used in the benchmarking of phase change flows. For higher flow regimes, the two-group two-fluid IATE model can separately model the transport of spherical bubbles and cap/slug bubbles. A modified formulation of the one-group and two-group two-fluid model with interfacial area transport equation (IATE) was recently proposed for gas-dispersed condensing flows. A new validation dataset was recently collected in a well scaled annulus facility for benchmarking the various IAC approaches. Validation of the different IAC modeling approaches against existing data show that the two-group model gives the best agreement overall with the experimental data for void fraction and interfacial area concentration. Modeling deficiencies are highlighted to further improve the two-group two-fluid IATE model.