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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 631 records · Page 35
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NASA NTRS2024

Validation & Verification of CFD Models for Cryogenic Fluid Management of Propellant Tanks in Space

This article describes the need and the strategy for CFD model development, validation, and verification for Cryogenic Fluid Management (CFM) of Propellant Tanks in Space. It describes the type of CFD models that must be developed to address the future needs of Space CFM. It also discusses the two classes of experiments currently used to validate the fidelity of the CFD models. These two experiment classes are: (a) the small-scale simulant fluid science experiments that are equipped with scientific diagnostics to elucidate the underlying two-phase fluid physics of the CFM processes; and (b) the large-scale cryogenic experiments that assess the engineering performance of the propellant tank for storage and transfer. The current status of the CFD model development and validation is briefly assessed by presenting examples of segregated two-phase flow problems that have been successfully modeled. The future model development directions for CFM situations involving more complex interpenetrating phases are also defined.

Cryogenic Fluid Management↗
NASA NTRSDate not supplied

Improved Models for Simulation of Cryogenic Spray Cooling for Propellant Tank Chilldown

This paper presents advances in spray boiling models for cryogenic fluids that exhibit strong variation in thermodynamic properties; it accounts for the interaction of the spray droplets with walls and the complex heat transfer and boiling processes that play a vital role in chilling solid surfaces. The model has been developed by corroborating and validating it with test data in liquid nitrogen obtained at the University of Connecticut. The test data includes detailed visualization and plate temperature measurements for liquid nitrogen sprays impinging on a warm test plate and subsequent transient chilldown of the plate. Simulations of transient plate chilldown in liquid nitrogen were carried out and temperature histories at various locations on the plate were compared with test measurements to demonstrate the validity of the spray boiling models that have been developed for cryogens.

Boiling↗
NASA NTRSDate not supplied

Joule-Thomson Cryogenic Nitrogen Orifice Flows

The Joule-Thomson Effect involves the expansion of a fluid through a throttling device, often a simple orifice, resulting in a change in the fluid's temperature. It has been leveraged in the design and analysis of Thermodynamic Vent Systems and integrated into injector designs for cryogenic no-vent fill tank-to-tank transfer testing. There is a scarcity of comprehensive data available to model the phenomenon effectively using tools such as GFSSP for cryogenic nitrogen flows. This experiment aims to model the Joule-Thomson effect of liquid nitrogen through seven traditionally manufactured, sharp-edged orifices manufactured by O’Keefe and three additively manufactured (AM) orifices manufactured by Cumberland Additive. The traditional orifice sizes were 0.016, 0.02, 0.024, 0.032, 0.037, and 0.04 inch in diameter. The three additive orifices had diameters with target/nominal sizes equal to the 0.016, 0.024, and 0.04 inch O’Keefe orifices. However, the actual diameters of the AM orifices were found to be 0.014, 0.024, and 0.035 inches due to additive manufacturing restrictions. Water was flowed through the orifices to verify that their flow coefficients matched published values and to establish flow coefficients for the AM orifices. Liquid nitrogen was flowed through the orifices in a separate test apparatus. The liquid nitrogen started as a subcooled liquid upstream of the orifice and transitioned into a two-phase gas-liquid mixture after passing through each orifice. The upstream pressure was set to 29 psia, 34 psia, 39 psia, and/or 42 psia or 44 psia. The pressure, temperature, and flow rate were measured upstream and downstream of the orifice for three trials at each set point. The average volumetric flow rate and Joule-Thomson Coefficients were calculated from this data. The AM orifices and traditionally manufactured orifices displayed similar results. This data will refine the dataset GFSSP uses to model the J-T Effect more accurately.

Joule-Thomson↗
NASA NTRSDate not supplied

Improved Models for Simulation of Cryogenic Spray Cooling for Propellant Tank Chilldown

This paper presents advances in spray boiling models for cryogenic fluids that exhibit strong variation in thermodynamic properties; it accounts for the interaction of the spray droplets with walls and the complex heat transfer and boiling processes that play a vital role in chilling solid surfaces. The model has been developed by corroborating and validating it with test data in liquid nitrogen obtained at the University of Connecticut. The test data includes detailed visualization and plate temperature measurements for liquid nitrogen sprays impinging on a warm test plate and subsequent transient chilldown of the plate. Simulations of transient plate chilldown in liquid nitrogen were carried out and temperature histories at various locations on the plate were compared with test measurements to demonstrate the validity of the spray boiling models that have been developed for cryogens.

Boiling↗
NASA NTRSDate not supplied

Modeling Self-Pressurization and Spray Bar Pressure Control of A Cryogenic Storage Tank in Normal Gravity

This paper presents computational fluid dynamics (CFD) models for simulating self-pressurization and spray-bar pressure control processes in a large-scale liquid hydrogen storage tank under normal gravity conditions. For self-pressurization, the model employs the kinetics-based Schrage equation alongside the volume-of-fluid (VOF) method to account for interfacial mass transfer. The CFD predictions of pressure and temperature are compared with experimental data from the Multipurpose Hydrogen Test Bed (MHTB) experiment, and the predicted interfacial mass transfer rates are also presented. A CFD model simulating pressure control using a spray bar has also been developed. An Eulerian-Lagrangian approach models the interactions between discrete droplets and the continuous ullage (vapor) phase. The spray model is coupled with the VOF method by tracking droplets in the ullage and removing them when they reach the liquid interface. The T-sat model calculates droplet-ullage heat and mass transfer, where droplets warm up to the saturation temperature corresponding to the ullage vapor pressure before evaporating while remaining at the saturation temperature. The evolution of tank pressure, vapor temperature, and liquid temperature predicted by the CFD model is validated against data from the MHTB spray-bar mixing experiment. Overall, the CFD models agree with experimental data, demonstrating their capability to simulate self-pressurization and pressure control processes in large-scale cryogenic storage tanks. These models can be valuable tools for designing and optimizing cryogenic fluid management systems in future applications.

Computational Fluid Dynamics↗
NASA NTRSDate not supplied

Modeling Self-Pressurization and Spray Bar Pressure Control of A Cryogenic Storage Tank in Normal Gravity

This paper presents computational fluid dynamics (CFD) models for simulating self-pressurization and spray-bar pressure control processes in a large-scale liquid hydrogen storage tank under normal gravity conditions. For self-pressurization, the model employs the kinetics-based Schrage equation alongside the volume-of-fluid (VOF) method to account for interfacial mass transfer. The CFD predictions of pressure and temperature are compared with experimental data from the Multipurpose Hydrogen Test Bed (MHTB) experiment, and the predicted interfacial mass transfer rates are also presented. A CFD model simulating pressure control using a spray bar has also been developed. An Eulerian-Lagrangian approach models the interactions between discrete droplets and the continuous ullage (vapor) phase. The spray model is coupled with the VOF method by tracking droplets in the ullage and removing them when they reach the liquid interface. The T-sat model calculates droplet-ullage heat and mass transfer, wherein droplets warm up to the saturation temperature corresponding to the ullage vapor pressure before evaporating while remaining at the saturation temperature. The evolution of tank pressure, vapor temperature, and liquid temperature predicted by the CFD model is validated against data from the MHTB spray-bar mixing experiment. Overall, the CFD models agree with experimental data, demonstrating their capability to simulate self-pressurization and pressure control processes in large-scale cryogenic storage tanks. These models can be valuable tools for designing and optimizing cryogenic fluid management systems in future applications.

Self-Pressurization↗
NASA NTRS1966

Feed-thru flange is useful in vacuum applications to cryogenic temperatures

Feed-thru flange seals inner and outer walls of high vacuum test chambers. It is used in vacuum applications at both cryogenic and higher than cryogenic temperatures. A damaged flange can still be used for partial vacuum, noncryogenic applications in conjunction with an appropriate rubber seal.

Yager, S. P.↗
NASA NTRS1967

Concept for cryogenic liquid reclamation system

Cryogenic liquid reclamation system is used as an add-on unit to the nitrogen system of environmental test laboratories to salvage liquid nitrogen presently being treated as waste. The system may be installed indoors or outdoors provided the gas boiled off from the cryogenic liquid is vented to the outside.

Daderian, S. M.↗
NASA NTRS1967

Handbook of cryogenic data in graphic form

Handbook of Cryogenic Data is written in graphic form and concentrates extensive data on common materials of construction and properties of fluids frequently encountered in designing cryogenic systems. All data are presented in the British system of units.

Loeb, M. B.↗
NASA NTRS1968

Cryogenic seal concept for static and dynamic conditions

Seal rings reduce cryogenic pump seal leakage under static and dynamic conditions. The rings are fitted into annular diaphragms, which are affected by cryogenic pressure and temperature, to move against a mating ring, to increase seal-bearing loads under static conditions.

De Gaetano, E. A.↗
NASA NTRS1967

A study of cryogenic container thermodynamics during propellant transfer. Volume 2 - Final engineering report

This report describes the results of a study of cryogenic container thermodynamics during propellant transfer. The purpose of this study is to provide analytical and empirical descriptions of the transient phenomena occurring in cryogenic transfer lines and receive tanks during initial propellant transfer. A further basic objective is to identify those conditions which give rise to the possibility of tank implosion, and to establish the procedures and/or systems necessary to eliminate this possibility.

R M Vernon↗
NASA NTRS1969

Control for maintaining constant level of a cryogenic liquid

Pressure formed as the cryogenic liquid vaporizes is used to pump new cryogenic liquid from a storage reservoir. Changes in volume of a gas resulting from changes in temperature actuate a valve which either replenishes the depleted liquid in the vessel or vents the evolving gas to the atmosphere.

Liberotti, J.↗