A review of flow boiling heat transfer with twisted tape inserts

This report reviews experimental investigations of in-tube flow boiling enhancement using twisted tape inserts. Special aspects of the experimental methods used in these studies are described in detail, and the general trends observed in the results are presented. Methods of mathematically characterizing the geometric parameters associated with swirl Bow are introduced, and the theoretical relationships between swirl Bow and axial Row boiling are described. Previously proposed empirical and semi-empirical predictive methods are presented for heat transfer and pressure drop with twisted tape inserts in various convective boiling regimes. These existing correlations are compared, and recommendations are made regarding experimental methods, design practices, and the use of existing predictive methods.