BOILING HOT ISSUES - SOME RESOLVED AND SOME NOT-YET-RESOLVED

The paper presents an overview of flow boiling heat transfer in terms of various key issues, some of which have been resolved satisfactorily in the recent years and others are still waiting. Topics of flow boil ing mechanisms, similarity between the convective component of flow bo iling and condensation heat transfer, two-phase flow patterns and the onset of boiling are covered. Additionally, the industrially relevant topics of boiling in narrow channels of compact exchangers and boiling of multicomponent fluids are also discussed. In the general context O f not-yet resolved issues, areas where the current level of informatio n is insufficient and new research efforts are warranted are also high lighted.