A General Heat Transfer Correlation for Annular Flow Condensation

The interaction between friction, momentum, and gravity, as they affect the heat transfer process during annular flow condensation inside tubes, is studied. Analytical forms for each of these forces are derived and incorporated in a correlation that predicts the local heat transfer coefficient. The predictions agree well with the available experimental data over a wide range of vapor velocities and over a range of Prandtl numbers from 1 to 10. The analysis also yields a means for predicting the onset of liquid run-back in the presence of an adverse gravitational field.