Thermal Desktop Modeling of 2016 CRYOTE-2 Tank Chill and Fill Testing

The storing and transfer of cryogenic propellants is an enabling technology for NASA and industry as civilization moves to expand future missions into low Earth orbit and beyond. Several ground propellant transfer tests have been conducted in past decades examining various tank chilldown and fill methods. Creating accurate models using these historical datasets is a vital step toward developing appropriate modeling tools to form pre-test predictions for subsequent ground and flight propellant transfers. This paper presents model validation of Thermal Desktop using data from the 2016 CRYOTE-2 liquid nitrogen transfer experiments whose purpose was to demonstrate the chill and fill process in a spherical receiver tank. Tank pressure, fill level, and wall temperature were all modeled and compared with 8 test cases using two modeling methods, Mass Controlled, and Pressure Controlled. This test series is the hardest Thermal Desktop tank chill and fill validation case to-date, yet the model was able to accurately predict each of these metrics for the 2016 tests within 28%, 10%, 20% respectively, for pressure, fill level, and wall temperature using the Mass Controlled model, and 29%, 79%, and 12%, respectively for the Pressure Controlled model.