Flow Characteristics of Gas-Liquid-Solid Three-Phase Flow in Civil Aircraft Waste System Study on Simulation Calculation

Abstract

The civil aircraft wastewater treatment system collects the aircraft toilet wastewater, hand washing grey water, and galley grey water into the waste water tank to solve the health and physiological needs of members on board. In this paper, taking the long branch of the waste system of civil aircraft as the research object, 1:1 modeling was carried out, and the multiphase flow of the long branch of the waste system was numerically simulated by using the CFD-DEM calculation model. The gas-liquid-solid three-phase flow form and flow characteristics of the long branch of the waste system were analyzed. The results show that under the conditions of a liquid-solid ratio of 2.5:1 and a system pressure difference of 55158 Pa, the total flow time of the solid phase is 1.6 s and the total flow time of the liquid phase is 1.95 s, which meets the design control time of 4 s for the long branch of the waste system. For the cross-sectional velocity of the pipeline, the gas velocity is greater than that of the liquid, and the liquid velocity is greater than that of the solid. The study on the flow performance of civil aircraft wastewater systems can provide theoretical support for the development of wastewater systems.