Frictional pressure drop of gas-liquid two-phase flow in vertical and inclined upward tubes under heaving oscillation

The study on gas-liquid two-phase flow characteristics of heaving oscillation is of great significance for the safe operation of offshore floating nuclear power platform. In this work, the frictional pressure drop of gas-liquid twophase flow in vertical and inclined upward tubes under heaving oscillation was studied experimentally. The oscillation frequency was sequentially varied through values of 0.21, 0.42, 0.7 and 0.98 Hz, whereas the oscillation amplitude was 100, 150 and 180 mm. The diameter of the tube was 15, 20 and 25 mm, whereas the inclination angle was 60, 70, 80 and 90 degrees. In total, 579 experimental data points were obtained and used to verify the 24 existing models of frictional pressure drop. The results showed that the existing models had relatively large errors in the calculation of frictional pressure drop under heaving oscillation. Considering the influence of additional force, the calculation method of liquid-phase conversion coefficient was improved, and the new model for the frictional pressure drop in gas-liquid two-phase flow for vertical and inclined upward tubes under heaving oscillation was established. It was found that the model established in this paper can greatly improve the accuracy of frictional pressure drop calculations under heaving oscillation.

Automated summary

This study experimentally investigated the frictional pressure drop characteristics of gas-liquid two-phase flow in vertical and inclined upward tubes under heaving oscillation. It was found that existing models had large errors in calculating the frictional pressure drop under heaving oscillation, and a new model was established to improve the accuracy of calculations.