Tuesday, March 15, 2022

Cryogenic Fluid Management of Liquid Hydrogen...

Executive Summary

This report provides passive cryogenic fluid management (CFM) insights, methods, equations, and algorithms suitable for performing system designs and trades. The content is intended for engineers, designers, analysts, managers and others who are developing or operating passive CFM systems.

Topics covered are based on cryogenic systems subject matter expertise at Moran Innovation LLC that has been developed over the past 35 years. Each main section concludes with calculation examples to demonstrate how to use the equations presented and interpret the results.

Main sections and subsections include:
  • Introduction to mission and vehicle drivers, thermophysical properties, thermodynamic behavior, fluid dynamics and heat transfer.
  • Acceleration and thermal environments, and how these environments vary based on mission segment.
  • Tankage for the storage of cryogenic propellants including: material properties; design and sizing; heat loads and insulation; and packaging and integration.
  • Venting of cryogenic tanks and associated implications such as: cryogen losses; liquid level rise in low gravity; and utilization of vent gas for propulsive settling and/or structural cooling.
  • Pressurization and pressure response of tanks including: active pressurization, interfacial heat and mass transfer, self-pressurization, and ullage collapse.
  • Other passive CFM topics including: chilldown and tank filling; tank internal insulation and structures; tank external structures and components; mass and energy balance; and propellant tracking.
  • References section with all sources cited in the footnotes; and an Appendix with instructions on how to access additional online content, and information on Moran Innovation LLC.

Online Access

The report is available online and can be accessed at:

The online version is a shared document in pdf format with viewer permission granted. Download and print functions are disabled. If you are having difficulty accessing the document, check with the IT department at your organization to ensure online access to shared Google Docs is permitted.

Matt Moran is the Managing Member at Moran Innovation LLC, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems for more than 40 years; and first-of-a-kind liquid, slush and gaseous hydrogen systems since the mid-1980s. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been a cofounder in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations. Matt has three patents and more than 50 publications including the Cryogenic Fluid Management report series. More about him can be found here.