Influential factors for liquid acquisition device screen selection for cryogenic propulsion systems

• The set of factors which dictate LAD design for all cryogenic propulsion systems are presented.
• Bubble point pressure, flow through screen pressure are primary factors.
• Wicking rate, screen compliance, and material compatibility are secondary factors.
• Governing equations are derived to create models for each influential factor.
• Each analytical model is validated by nearly 4 decades of experimental data.

This paper presents the influential factors which govern screen selection for liquid acquisition devices (LADs) operating in microgravity conditions for future in-space cryogenic propulsion engines and cryogenic propellant depots. Space flight requirements, which include mass flow rate, acceleration level and direction, and thermal environment, dictate screen selection for a particular mission. The five influential factors include bubble point pressure, flow-through-screen pressure drop, wicking rate, screen compliance, and material compatibility. Governing equations and analytical models for these parameters are developed from first principles. A comprehensive survey of the historical data on coarser LAD meshes over four decades of work is conducted, and liquid hydrogen data for finer Dutch Twill meshes (325 × 2300, 450 × 2750, 510 × 3600) from recently concluded experiments is also presented to validate analytical models. Each of these parameters is measurable from ground based tests, making it facile to predict flight system performance. Therefore analytical models in this paper will be valuable for future LAD designs for both cryogenic and storable propulsion systems. Additionally, analysis will be given on the impact of the factors on liquid hydrogen systems.