A generalized correlation for pressure drop prediction in helically coiled tubes across different geometries and operating conditions

In the nuclear sector, helically coiled tube heat exchangers (HCTs) are considered promising for steam generators in Small Modular Reactors (SMRs). However, their complex geometry makes the accurate prediction of pressure losses more challenging, especially in twophase flows. Existing correlations are generally valid within their specific range of applicability but often lack generality across different geometries, pressures, and flow conditions. This study aims to develop an improved correlation for the pressure drop estimation in HCTs, extending its applicability to various geometric configurations and operating conditions. The proposed correlation is validated against experimental data from the literature and compared with existing models to assess their accuracy and reliability.