NASA Engineers Simulate Gas Flow and Heat Transfer

J. Knox, R. Coker
NASA Marshall Space Flight Center, AL, USA

To ensure astronaut safety on space missions, it is necessary to routinely revitalize the atmosphere in manned spacecraft. Jim Knox, Rob Coker, and a team of engineers at the NASA Marshall Space Flight Center have developed a water-saving system called an Isothermal Bulk Dessicant (IBD). The IBD is used to collect water from the atmosphere for re-use. It consists of packed beds lined with silica gel; as air flows through, water is adsorbed onto the silica gel and then transferred back to the atmosphere through desorption once the air has continued on to a CO2 removal system. Using a COMSOL Multiphysics model, Knox and Coker simulated the gas flow and heat transfer in a four-bed IBD. They tracked the flow rates, pressure conditions, and water concentration as water adsorbed and desorbed. Their model predicted that the IBD successfully saved 85% of the water from the atmosphere. As they use COMSOL to optimize their designs, they hope to offer NASA integrated systems that will enable farther space travel than ever before.