Search NASA⌕ Search

SEARCH · Search NASA

Results for “liquid hydrogen”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Constant reverse thrust activated reorientation of liquid hydrogen with Geyser initiation

A key objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquisition or positioning of liquid outflow or vapor venting. Numerical simulation of positive liquid acquisition is attempted by introducing reverse gravity acceleration, resulting from the propulsive thrust of auxiliary engines, which exceeds critical value for the initiation of geyser. Based on the computer simulation of flowfields during the course of fluid reorientation, six dimensionless parameters resulted in this study. It shows that these parameters hold near-constant values through the entire ranges of liquid filled levels, from 30-80 percent, during the course of fluid reorientation.

Hung, R. J.↗
NASA NTRS1978

Study of thermal insulation for airborne liquid hydrogen fuel tanks

A concept for a fail-safe thermal protection system was developed. From screening tests, approximately 30 foams, adhesives, and reinforcing fibers using 0.3-meter square liquid nitrogen cold plate, CPR 452 and Stafoam AA1602, both reinforced with 10 percent by weight of 1/16 inch milled OCF Style 701 Fiberglas, were selected for further tests. Cyclic tests with these materials in 2-inch thicknesses bonded on a 0.6-meter square cold plate with Crest 7410 adhesive systems, were successful. Zero permeability gas barriers were identified and found to be compatible with the insulating concept.

Ruccia, F. E.↗
NASA NTRS1984

Capture of liquid hydrogen boiloff with metal hydride absorbers

A procedure which uses metal hydrides to capture some of this low pressure (,1 psig) hydrogen for subsequent reliquefaction is described. Of the five normally occurring sources of boil-off vapor the stream associated with the off-loading of liquid tankers during dewar refill was identified as the most cost effective and readily recoverable. The design, fabrication and testing of a proof-of-concept capture device, operating at a rate that is commensurate with the evolution of vapor by the target stream, is described. Liberation of the captured hydrogen gas at pressure .15 psig at normal temperatures (typical liquefier compressor suction pressure) are also demonstrated. A payback time of less than three years is projected.

Rosso, M. J.↗
NASA NTRS1995

Impact damage resistance of carbon/epoxy composite tubes for the DC-XA liquid hydrogen feedline

Low-velocity impacts were inflicted upon two elbow sections of carbon/epoxy feedline that are to be a part of the Delta Clipper-XA flight vehicle. A soap-based liquid leak detector solution was used to inspect the impact sites for leaks of pressurized gas that was pumped into the tube. Visual surface damage was noted and recorded for each impact site. After impact testing of each of the two sections of tubes was completed, the damage zones were disected from the tube and cross sectioned through the impact site. These specimens were polished after potting them in epoxy and were examined for microcracking using a fluorescent dye penetrant technique. The results showed that nonvisible damage could cause microcracking, thereby resulting in leaks through the tube wall.

Nettles, A. T.↗
NASA NTRS1990

Cryogenic liquid hydrogen reorientation activated by constant reverse gravity acceleration of geyser initiation

A key objective for cryogenic fluid management in a spacecraft propulsion system is development of the technology necessary for acquisition or positioning of liquid outflow or vapor venting. Numerical simulation of positive liquid acquisition is attempted by introducing a reverse gravity acceleration from the propulsive thrust of auxiliary engines which exceeds critical value for the initiation of a geyser. Based on the computer simulation of flow fields during the course of fluid reorientation, six dimensionless parameters resulted. These parameters hold near-constant values through the entire range of liquid filled levels, from 30 to 80 percent, during the course of fluid reorientation.

Hung, R. J.↗
NASA NTRS2016

Additive Manufacturing a Liquid Hydrogen Rocket Engine

Space Propulsion is a 5 day event being held from 2nd May to the 6th May 2016 at the Rome Marriott Park Hotel in Rome, Italy. This event showcases products like Propulsion sub-systems and components, Production and manufacturing issues, Liquid, Solid, Hybrid and Air-breathing Propulsion Systems for Launcher and Upper Stages, Overview of current programmes, AIV issues and tools, Flight testing and experience, Technology building blocks for Future Space Transportation Propulsion Systems : Launchers, Exploration platforms & Space Tourism, Green Propulsion for Space Transportation, New propellants, Rocket propulsion & global environment, Cost related aspects of Space Transportation propulsion, Modelling, Pressure-Thrust oscillations issues, Impact of new requirements and regulations on design etc. in the Automotive, Manufacturing, Fabrication, Repair & Maintenance industries.

Jones, Carl P.↗
NASA NTRS1992

Medium-frequency impulsive-thrust-activated liquid hydrogen reorientation with Geyser

Efficient technique are studied for accomplishing propellant resettling through the minimization of propellant usage through impulsive thrust. A comparison between the use of constant-thrust and impulsive-thrust accelerations for the activation of propellant resettlement shows that impulsive thrust is superior to constant thrust for liquid reorientation in a reduced-gravity environment. This study shows that when impulsive thrust with 0.1-1.0-, and 10-Hz frequencies for liquid-fill levels in the range between 30-80 percent is considered, the selection of 1.0-Hz-frequency impulsive thrust over the other frequency ranges of impulsive thrust is the optimum. Characteristics of the slosh waves excited during the course of 1.0-Hz-frequency impulsive-thrust liquid reorientation were also analyzed.

Hung, R. J.↗
NASA NTRS2018

Toughness Testing for Liquid Hydrogen And Helium Temperatures - Validation of Austenitic Stainless Steels for 4K (-452F) Use

This presentation is an Existing Code Requirement: Charpy impact test at a temperature no higher than the design minimum temperature. The Current Practice: is not clear, the indications are that testing is sometimes performed at -320F (liquid nitrogen or "LN2") for that and all lower temperatures. In some cases testing is probably not performed and CGA indicated successful operation of systems at -453F without required test. The Ballot activity: C&S Connect Record 13-341, Ballot 13-1746, initially proposed Charpy testing (lateral expansion criteria) at -320F to validate use at -425 (liquid helium or "LHe"). and PTCS Proposal..

Greulich, Owen R.↗
NASA NTRS2017

Reduced Order Modeling of SLS Liquid Hydrogen Pre-Valve Flow Guide to Enable Rapid Transient Analysis

NASA is developing a new launch vehicle, called the Space Launch System (SLS), which is intended on taking humans out of low earth orbit to destinations including the moon, asteroids, and Mars. The propulsion system for the core stage of this vehicle includes four RS-25 Liquid Hydrogen/Oxygen rocket engines. These engines are upgraded versions of the Space Shuttle Main Engines (SSME); the upgrades include higher power levels and affordability enhancements. As with any new vehicle, the Main Propulsion System (MPS), which include the feedlines and ancillary hardware connecting the engines to the fuel and oxidizer tanks, had to be redesigned (figure 1 - export clearance in progress), as the previous MPS for the SSME's was inherently part of the Space Shuttle System, which had a completely different overall configuration.

Brown, Andrew M.↗
NASA NTRS1989

ALS liquid hydrogen turbopump: Advanced Development Program

The point of departure (POD) turbopump concept was reviewed and finalized. The basis for the POD was the configuration presented in the Aerojet proposal. After reviewing this proposal concept, several modifications were made. These modifications include the following: (1) the dual pump discharge arrangement was changed to a single discharge; (2) commonality of the turbine inlet manifold with the advanced launch system (ALS) liquid oxygen (LOX) TPA was dropped for this program; (3) the turbine housing flange arrangement was improved by relocating it away from the first stage nozzles; (4) a ten percent margin (five percent diameter increase) was built into the impeller design to ensure meeting the required discharge pressure without the need for increasing speed; (5) a ten percent turbine power margin was imposed which is to be obtained by increasing turbine inlet pressure if required; and (6) the backup concept, as an alternative to the use of cast impellers, now incorporates forged/machined shrouded impellers, rather than the unshrouded type originally planned.

Shimp, Nancy R.↗
NASA NTRS2017

Pressurization of a Flightweight, Liquid Hydrogen Tank: Evaporation & Condensation at a Liquid/Vapor Interface

This paper presents an analysis and simulation of evaporation and condensation at a motionless liquid/vapor interface. A 1-D model equation, emphasizing heat and mass transfer at the interface, is solved in two ways, and incorporated into a subgrid interface model within a CFD simulation. Simulation predictions are compared with experimental data from the CPST Engineering Design Unit tank, a cryogenic fluid management test tank in 1-g. The numerical challenge here is the physics of the liquid/vapor interface; pressurizing the ullage heats it by several degrees, and sets up an interfacial temperature gradient that transfers heat to the liquid phase-the rate limiting step of condensation is heat conducted through the liquid and vapor. This physics occurs in thin thermal layers O(1 mm) on either side of the interface which is resolved by the subgrid interface model. An accommodation coefficient of 1.0 is used in the simulations which is consistent with theory and measurements. This model is predictive of evaporation/condensation rates, that is, there is no parameter tuning.

Stewart, Mark E. M.↗
DOE OSTI2024

Life Cycle Assessment of Formic Acid as a Liquid Hydrogen Carrier

This work presents a life cycle analysis of the transport and processing for formic acid into hydrogen. The system boundary begins at the formic acid plant gate and ends with hydrogen end use. The functional unit is 1 kg of hydrogen delivered to end use, 1 kWh for electricity generation, and 1 vehicle mile traveled (VMT). Renewable electricity reduced GWP by 80-90% relative to U.S. average grid.

Shen, Xinyao [NETL Site Support Contractor, Nation↗