The Effect of Liquid Withdrawal Rate on Screen Channel Liquid Acquisition Device Screen Compliance

In the absence of strong gravitational forces in the microgravity environment of space, surface tension forces dominate, and special devices called liquid acquisition devices (LADs) are required to separate and control liquid and vapor phases of the propellant upstream in the storage tank to prevent vapor ingestion into the transfer line. One type of device called a screen channel LAD uses three solid sides and one porous side of a channel to allow liquid to flow, but also to act as a barrier to vapor ingestion. During the transient startup of propellant transfer, the liquid must be accelerated from rest to the steady flow demand velocity, which causes the screen to deflect or comply. Compliance data is required for accurate transient LAD analyses; most design codes only consider steady state analysis. (Camarotti et al. in Microgravity Sci Technol 31: 109-122, 2019h). presented fundamental screen compliance data as a function of mesh type for circular screen geometries. The purpose of this paper is to present the effect of ramp rate (i.e. the volumetric flow rate at which liquid is withdrawn from underneath the screen) on LAD screen compliance for rectangular screen geometries. Three different screen types and three different aspect ratios were tested across a wide range of liquid withdrawal rates using isopropyl alcohol (IPA) to examine this effect.

Automated summary

In the microgravity environment of space, liquid acquisition devices (LADs) are used to separate and control liquid and vapor phases of propellant. This study investigates the effect of different ramp rates on the compliance of LAD screens with rectangular geometries.