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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Advantageous use of slush and gelled slush in space vehicles

The advantages of combining both slush and gel have been recognized. These advantages are: (1) a reduction in the gelling agent necessary; (2) the achievement of active positioning; and (3) a potential increase in impulse density. The need for extended mission capability as indicated by present mission planning is outlined and the expected schedules are presented. A condensed version of analytical and testing conclusions as related to storage systems and slush is given. The significant results of slush flow testing and its possible influence on vehicle propulsion systems are presented, and the characterization and preparation of gels are discussed in relation to future applications, advantages, and disadvantages.

Adamson, J. Z.↗
NASA NTRS1991

Slush hydrogen propellant production, transfer, and expulsion studies at the NASA K-Site Facility

Slush hydrogen is currently being considered as a fuel for the National AeroSpace Plane (NASP) because it offers the potential for decreased vehicle size and weight. However, no large scale data was available on the production, transfer, and tank pressure control characteristics required to use the fuel for the NASP. Therefore, experiments were conducted at NASA-Lewis K-Site Facility to improve the slush hydrogen data base. Slush hydrogen was produced using the evaporative cooling, or freeze-thaw, technique in batches for approx. 800 gallons. This slush hydrogen was pressure transferred to a 5 ft diameter spherical test tank following production, and flow characteristics were measured during this transfer process. The slush hydrogen in the test tank was pressurized and expelled using a pressurized expulsion technique to obtain information on tank pressure control for the NASP. Results from the production, transfer, pressurization, and pressurized expulsion tests are described.

Hardy, Terry L.↗
NASA NTRS1991

Slush hydrogen propellant production, transfer, and expulsion studies at the NASA K-Site Facility

Slush hydrogen is currently being considered as a fuel for the National Aero-Space Plane (NASP) because it offers the potential for decreased vehicle size and weight. However, no large-scale data was available on the production, transfer, and tank pressure control characteristics required to use the fuel for the NASP. Therefore, experiments were conducted at the NASA Lewis Research Center K-Site Facility to improve the slush hydrogen database. Slush hydrogen was produced using the evaporative cooling, or freeze-thaw, technique in batches of about 800 gallons. This slush hydrogen was pressure transferred to a 5 ft diameter spherical test tank following production, and flow characteristics were measured during this transfer process. The slush hydrogen in the test tank was pressurized and expelled using a pressurized expulsion technique to obtain information on tank pressure control for the NASP. Results from the production, transfer, pressurization, and pressurized expulsion tests are described.

Hardy, Terry L.↗
NASA NTRS1992

Slush hydrogen pressurized expulsion studies at the NASA K-Site Facility

An experiment test series of the slush hydrogen (SLH2) project at the NASA LeRC Plum Brook K-Site Facility was completed. This testing was done as part of the characterization and technology database development on slush hydrogen required for the National Aero-Space Plane (NASP) Program. The primary objective of these experiments was to investigate tank thermodynamic parameters during the pressurized expulsion of slush hydrogen. To accomplish this, maintenance of tank pressure control was investigated during pressurized expulsion of slush hydrogen using gaseous hydrogen and gaseous helium pressurant. In addition, expulsion tests were performed using gaseous helium for initial pressurization, then gaseous hydrogen during expulsion. These tests were conducted with and without mixing of the slush hydrogen. Results from the testing included an evaluation of tank pressure control, pressurant requirements, SLH2 density change, and system mass and energy balances.

Whalen, Margaret V.↗
NASA NTRS1992

Slush hydrogen pressurized expulsion studies at the NASA K-Site Facility

An experiment test series of the slush hydrogen (SLH2) project at the NASA LeRC Plum Brook K-Site Facility was completed. This testing was done as part of the characterization and technology database development on slush hydrogen required for the National Aero-Space Plane (NASP) Program. The primary objective of these experiments was to investigate tank thermodynamic parameters during the pressurized expulsion of slush hydrogen. To accomplish this, maintenance of tank pressure control was investigated during pressurized expulsion of slush hydrogen using gaseous hydrogen and gaseous helium pressurant. In addition, expulsion tests were performed using gaseous helium for initial pressurization, then gaseous hydrogen during expulsion. These tests were conducted with and without mixing of the slush hydrogen. Results from the testing included an evaluation of tank pressure control, pressurant requirements, SLH2 density change, and system mass and energy balances.

Whalen, Margaret V.↗
NASA NTRS1995

A Summary of the Slush Hydrogen Technology Program for the National Aero-Space Plane

Slush hydrogen, a mixture of solid and liquid hydrogen, offers advantages of higher density (16 percent) and higher heat capacity (18 percent) than normal boiling point hydrogen. The combination of increased density and heat capacity of slush hydrogen provided a potential to decrease the gross takeoff weight of the National Aero-Space Plane (NASP) and therefore slush hydrogen was selected as the propellant. However, no large-scale data was available on the production, transfer and tank pressure control characteristics required to use slush hydrogen as a fuel. Extensive testing has been performed at the NASA Lewis Research Center K-Site and Small Scale Hydrogen Test Facility between 1990 and the present to provide a database for the use of slush hydrogen. This paper summarizes the results of this testing.

Mcnelis, Nancy B.↗
NASA NTRS1960

Studies of the Retardation Force Developed on an Aircraft Tire Rolling in Slush or Water

A series of unbraked (freely rolling) taxi tests were conducted at the Langley landing-loads track with a 32 x 8.8, type 7, 22-ply-rating ribbed-tread aircraft tire to obtain data on tire retardation forces developed during rolling in both slush and water. The forward speeds of the tests ranged from 59 to 104 knots. Tire inflation pressures of 350 and 115 pounds per square inch were used. Results indicated a parabolic increase of retardation force with increasing forward velocity for both slush- and water-covered runway surfaces. The retardation force was found to increase approximately linearly with increasing water depth. Drag coefficients appropriate to the equations used are presented. Calculations made to determine the effect of slush on the take-off distance of a jet transport are in agreement with data obtained from an actual take-off in slush for this airplane. This is an interim report which deals with the effect of slush on the acceleration and the ground-run distance of airplanes during take-off.

Horne, Walter B.↗
NASA NTRS1972

Part A: Hydrocarbon Suspension in Slush Hydrogen

Methods of preparing suspensions of a hydrocarbon in slush hydrogen for nuclear fuel element corrosion inhibition in rocket engines were investigated. Suspensions were prepared using approximately 5000 ppm by mass of methane, ethane, or cyclopropane in slush hydrogen. The suspensions were stable in the slush, but the hydrocarbons settled out of the liquid melt.

Sindt, C. F.↗
NASA NTRS1990

FLUSH: A tool for the design of slush hydrogen flow systems

As part of the National Aerospace Plane Project an analytical model was developed to perform calculations for in-line transfer of solid-liquid mixtures of hydrogen. This code, called FLUSH, calculates pressure drop and solid fraction loss for the flow of slush hydrogen through pipe systems. The model solves the steady-state, one-dimensional equation of energy to obtain slush loss estimates. A description of the code is provided as well as a guide for users of the program. Preliminary results are also presented showing the anticipated degradation of slush hydrogen solid content for various piping systems.

Hardy, Terry L.↗
NASA NTRS1991

Benefits of slush hydrogen for space missions

A study was performed to quantify the benefits of using slush hydrogen instead of normal boiling point liquid hydrogen as a fuel for several space missions. Vehicles considered in the study included the Space Shuttle/Shuttle-C, LEO to GEO transfer vehicles, Lunar and Mars transfer vehicles, and cryogenic depots in low Earth orbit. The advantages of using slush hydrogen were expressed in terms of initial mass differences at a constant payload, payload differences at a constant tank volume, and increases in fuel storage time for cryogenic depots. Both chemical oxygen/hydrogen and hydrogen nuclear thermal rocket propulsion were considered in the study. The results indicated that slush hydrogen offers the potential for significant decreases in initial mass and increases in payload for most missions studied. These advantages increase as the mission difficulty, or energy, increases.

Friedlander, Alan↗
NASA NTRS1992

Slush hydrogen transfer studies at the NASA K-Site Test Facility

An experimental study was performed as part of the National Aerospace Plane (NASP) effort to determine slush hydrogen production and transfer characteristics. Flow rate and pressure drop characteristics were determined for slush hydrogen flow through a vacuum-jacketed transfer system. These characteristics were compared to similar tests using normal boiling point and triple point hydrogen. In addition, experimental flow characteristic data was compared with predictions from the FLUSH analytical model. Slush hydrogen density loss during the transfer process was also examined.

Hardy, Terry L.↗
NASA NTRS1992

Slush hydrogen transfer studies at the NASA K-Site Test Facility

An experimental study was performed as part of the National Aerospace Plane (NASP) effort to determine slush hydrogen production and transfer characteristics. Flow rate and pressure drop characteristics were determined for slush hydrogen flow through a vacuum-jacketed transfer system. These characteristics were compared to similar tests using normal boiling point and triple point hydrogen. In addition, experimental flow characteristic data was compared with predictions from the FLUSH analytical model. Slush hydrogen density loss during the transfer process was also examined.

Hardy, Terry L.↗
NASA NTRS1971

Hydrogen slush density reference system

A hydrogen slush density reference system was designed for calibration of field-type instruments and/or transfer standards. The device is based on the buoyancy principle of Archimedes. The solids are weighed in a low-mass container so arranged that solids and container are buoyed by triple-point liquid hydrogen during the weighing process. Several types of hydrogen slush density transducers were developed and tested for possible use as transfer standards. The most successful transducers found were those which depend on change in dielectric constant, after which the Clausius-Mossotti function is used to relate dielectric constant and density.

Weitzel, D. H.↗
NASA NTRS1972

Slush hydrogen liquid level system

A discrete capacitance liquid level system developed is specifically for slush hydrogen, but applicable to LOX, LN2, LH2, and RP1 without modification is described. The signal processing portion of the system is compatible with conventional liquid level sensors. Compatibility with slush hydrogen was achieved by designing the sensor with adequate spacing, while retaining the electrical characteristics of conventional sensors. Tests indicate excellent stability of the system over a temperature range of -20 C to 70 C for the circuit and to cryogenic temperatures of the sensor. The sensor was tested up to 40 g's rms random vibration with no damage to the sensor. Operation with 305 m of cable between the sensor and signal processor was demonstrated. It is concluded that this design is more than adequate for most flight and ground applications.

Hamlet, J. F.↗