Simulation of cryogenic fluid filling of spacecraft

Most spacecrafts use cryogenic fuel due to their high energy density and easy storage. Cryogenic fuels will exist at sub-zero temperatures, which makes fueling of space-craft challenging. Fuel is generally pump into spacecraft by network of pipes which are generally at room temperature. When cryogenic fuel is suddenly injected into feedline it boils off to gaseous state, so system must be capable of expelling the gases. It also causes thermal shock which can damage pipelines. 

In order to prevent such scenarios we need to carry out a process to pre-cool projectile tank and the feed line. Korean aerospace research institute (KARI) took advantage of two phase capabilities of Simcenter Flomaster to run both steady and transient simulations to verify piping system and filling scenarios are performing as expected. Entire fuel filling schematic is modelled according to the schematic and fuel filling process is simulated which generally achieved in stages (fuel link chilling, projectile tank chilling and filling of tank). Time taken and pressure fluctuations are determined for  each stage is found and validated with actual experimental values..