Mathematical Simulation of Using a Combination of Mesh and Porous Materials as a Phase Separator

A combination of mesh and porous materials featuring bulk capillary properties is used as a phase separator in in-tank capillary inlet devices. These bulk capillary properties ensure a non-zero fluid flow into the interior of the in-tank inlet device after critical pressure has been reached. This quality makes it possible to reduce residual propellant volume in spacecraft engine tanks. We developed a mathematical simulation of an in-tank capillary inlet device comprising a phase separator made of a combination of mesh and porous materials. We represented a combination of mesh and porous materials as an array of "closely packed" transverse and longitudinal capillaries. Our mathematical simulation describes the operation of an in-tank inlet device after the critical manifold pressure has been reached. The fluid enters the interior of the in-tank inlet device one portion at a time. We determined the volume and arrival frequency of these portions and estimated the residual propellant volume in the propellant tank.