Absorbed-desorbed effects of ventilated pipeline

In on-orbit refueling pipelines, gas-liquid multiphase flow encounters challenges such as flow pattern transition triggered by vortices, backflow, and local pressure gradients, which causes flow blockage and compromises transportation efficiency. The reported gas-liquid mass-transfer models fail to associate the unidirectional absorption or desorption process. Therefore, an absorbed-evolved coupling model is developed to predict dynamic gas-liquid absorbed-desorbed mass-transfer behavior. After validation and verification of experiment and numerical schemes, multiphase flow calculations were conducted to reveal the flow pattern transition mechanisms and its spatial-temporal evolution. The results show that, for the conditions of the large orifice plate, the mean error between the simulations and experiments was less than 0.96 %, while for that of the small orifice plate, it was less than 1.28 %. The local pressure gradient is the primary factor affecting the flow pattern transition rather than the gas-liquid contacting time and free gas content. Notably, the concentration changes caused by the orifice pressure gradient lags behind the changes in hydrodynamic behavior and gas-liquid distribution, thereby contributing to the hysteresis of mass-transfer diffusion to convection. Current study provides critical guidance for refueling systems, demonstrating that achieving optimal synergy between pressurization levels and gas flow rate regulation is fundamental to enhancing transport capacity.