New Results in Two‐Phase Pressure Drop Calculations at Reduced Gravity Conditions

The mass, power, and volume energy savings of two‐phase systems for future spacecraft creates many advantages over current single‐phase systems. Current models of two‐phase phenomena such as pressure drop, void fraction, and flow regime prediction are still not well defined for space applications. Commercially available two‐phase modeling software has been developed for a large range of acceleration fields including reduced‐gravity conditions. Recently, a two‐phase experiment has been flown to expand the two‐phase database. A model of the experiment was created in the software to determine how well the software could predict the pressure drop observed in the experiment. Of the simulations conducted, the computer model shows good agreement of the pressure drop in the experiment to within 30%. However, the software does begin to over‐predict pressure drop in certain regions of a flow regime map indicating that some models used in the software package for reduced‐gravity modeling need improvement.