Hydrodynamic and Heat-and-Mass Transfer Processes in Space Station Water Recovery Systems
The paper systematizes typical hydrodynamic and heat-and-mass transfer chemical engineering processes realized in water recovery systems. The impact of micro-gravity on the processes is analyzed and general principles of the process organization in gas/liquid fluids are described. As examples, some typical separation processes in a coccurred flow channel with liquid suction through a porous wall, liquid evaporation into a vapour/gas fluid and vapour condensation from the vapour/gas mixture are considered for water recovery systems. A versatile approach based on an extended analogy between friction, heat transfer and mass transfer and on limited relative laws of a boundary layer at the permeable surface is suggested for an analysis and calculation of the friction resistance of a two-phase flow, heat transfer and mass transfer on evaporation and condensation. Recommendations for an analysis of the influence of free convection are made.