To support NASAs Cryogenic Fluid Management (CFM) design and operation initiatives, computational fluid dynamics (CFD) models of cryogenic condensation/liquification are required to allow for efficient trade studies to be conducted on real systems over a range of conditions that may be prohibitive with laboratory testing. In the Phase I effort, a validated subgrid CFD model of cryogenic film condensation on a vertical flat wall will be developed which is capable of capturing the formation and growth of a cryogenic condensation layer and its movement along a wall boundary. A systematic test campaign will be undertaken to investigate the downflow film condensation of various cryogenic fluids of CFM and In-Situ Resource Utilization (ISRU) relevance. The Phase I effort emphasizes experimental visualization of the onset of film condensation, understanding of relative importance of heat transfer processes, quantification of key film characteristics, including liquid film thickness, vapor thermal boundary layer, and condensation heat flux, and identification of governing parameters that influence cryogenic film formation and growth. The experimental data will be used for fundamental validation of a subgrid cryogenic film condensation CFD phase-change model, setting the stage for a Phase II validation program on prototype CFM geometries. The Phase II effort will extend the validation to tank geometries and incorporate the validated film condensation model into commercial CFD tools used by NASA. The validated predictive simulation tools will help in identifying better designs and protocols related to cryogenic propellant transfer and ISRU thereby mitigating risk in outer space hardware deployment and operational strategies. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Cryogenic Fluid Management (CFM) is in the critical path of nearly all NASAs future space exploration missions. A validated CFD cryogenic film condensation model will provide a unique simulation capability for tools being used by NASA for CFM design and operational initiatives including In-Situ-Resource-Utilization (ISRU) and in-space refueling for long-duration space exploration missions, which are currently a high priority area as NASA looks to return to the moon and explore Mars on an accelerated time frame. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Cryogenic Fluid Management affects many space-exploration initiatives and as the commercial space launch market continues to grow the market for high-fidelity cryogenic simulation software will expand to support design and operational strategies. Industries involved in liquefied gases, hydrogen as a green fuel, and the petroleum industry with liquefied natural gas also provide a potential market. Duration: 6
