On the annular‐to‐wavy flow pattern transition during condensation inside horizontal tubes

The annular to wavy and intermittent flow pattern transition during condensation inside horizontal tubes was investigated. Eight data sets corresponding to different tube diameters and different test fluids were used to test the predictions of several diabatic and adiabatic correlations. Deficiencies were found in these correlations which prevented consistent agreement with the data base. An improved correlation is proposed and shown to have a good deal of generality and accuracy in predicting this transition.