Simulations of single and two-phase flows through helical tubes with different geometries and mass flow rates

Predictions of pressure drops in helical pipes using the Relap5/mod3.3 code are explored, despite the code's limitations in modeling such geometries. To address this, the code was modified to incorporate helical tube geometries and correlations for frictional pressure drops under both single-phase and two-phase flow conditions. Comparisons with experimental data on pressure drops across test sections with varying curvature ratios, operational pressures, and mass flow rates were made. The study demonstrates that the modified Relap5 code significantly improves the accuracy of frictional pressure drop predictions for the examined experimental data. © 2025 Institute of Physics Publishing. All rights reserved.