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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 685 records · Page 38

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NASA NTRS1974

Vapor ingestion in a cylindrical tank with a concave elliptical bottom

An approximate analytical technique is presented for estimating the liquid residual in a tank of arbitrary geometry due to vapor ingestion at any drain rate and acceleration level. The bulk liquid depth at incipient pull-through is defined in terms of the Weber and Bond numbers and two functions that describe the fluid velocity field and free surface shape appropriate to the tank geometry. Numerical results are obtained for the Centaur LH2 tank using limiting approximations to these functions.

Klavins, A.↗

NASA NTRS1978

Purging of a tank-mounted multilayer insulation system by gas diffusion

The investigation was conducted on a multilayer insulation (MLI) system mounted on a spherical liquid hydrogen propellant tank. The MLI consisted of two blankets of insulation each containing 15 double-aluminized Mylar radiation shields separated by double silk net spacers. The gaseous nitrogen initially contained within the MLI system and vacuum chamber was purged with gaseous helium introduced both underneath the MLI and into the vacuum chamber. The MLI panels were assumed to be purged primarily by means of gas diffusion. Overall, test results indicated that nitrogen concentrations well below 1 percent could be achieved everywhere within the MLI system. Typical times to achieve 1 percent nitrogen concentration within the MLI panels ranged from 69 minutes at the top of the tank to 158 minutes at the bottom of the tank. Four space-hold thermal performance tests indicated no significant thermal degradation of the MLI system had occurred due to the purge tests conducted. The final measured heat input attributed to the MLI was 7.23 watts as compared to 7.18 watts for the initial baseline thermal performance test.

Sumner, I. E.↗

NASA NTRS1978

Constrained sloshing of liquid mercury in a flexible spherical tank

The mercury propellant tank system developed for use with solar electric propulsion was studied to analytically determine the resonant frequencies of the tank system and compare them with the anticipated control natural frequency of the spacecraft. The system consisted of a stainless steel spherical shell and a hemispherical elastometric diaphragm. The major analytical tool used was the NASTRAN program. Six mathematical models were developed. Resonant frequencies for six harmonics were obtained for each of the six models considered. The results show that the lowest resonant frequency for the tank system is about an order of magnitude greater than the anticipated control frequency of the spacecraft.

Lestingi, J.↗

NASA NTRS1978

Detection of internal defects in a liquid natural gas tank by use of infrared thermography

The use of an infrared scanning technique to detect defects in the secondary barrier of a liquid natural gas tank is described. The method works by detecting leak-caused temperature differences as low as 0.2 K, but can provide only an approximate idea of the extent of the defect. The nondestructive method was tested in a study of a LNG tank already at its location in a ship; the secondary barrier was located inside the tank wall. Defective areas indicated by the infrared radiometric measurements were confirmed by other probe techniques and by physical examination.

Kantsios, A. G.↗

NASA NTRS1979

Preflight status of the External Tank portion of the Space Shuttle Main Propulsion System

The development progress of the External Tank (ET) of the Shuttle Main Propulsion System (MPS) is described. 87% of ET propulsion components have satisfactorily completed qualification tests in preparation for the first Shuttle flight and their performance has been verified in the Main Propulsion Test Article (MPTA) firings of up to 100 seconds duration. The design changes in the LH2 tank pressurant diffuser, the LO2 feed system, and the ground test LO2 tank are discussed. Propellant loading information from MPTA tests may be used to predict loading operations and performance at KSC and VAFB, while ullage pressure profiles and boil-off rates during loading, chilldown rates, and final bulk density data have been obtained with geyser suppression evaluated and loading procedures established and verified. The MPTA test experience provided data to evaluate pressurization system and ET to Orbiter interface propellant performance noting thus that the fluid interface requirements will be satisfied for the first Shuttle flight. The Intertank inerting system was found to be effective in minimizing hazardous gas mixtures and full scale separation tests of the ET to Ground Umbilical Carrier Plate system were successfully completed.

Norquist, L.↗

NASA NTRS1980

Thermal stratification in liquid storage tanks

Comprehensive literature survey indicates thermal stratification in solarenergy/liquid-storage tank improves system performance by as much as 15 percent. Collector efficiency increases when collector inlet fluid is drawn from bottom of storage tank, where fluid is coolest; warmest liquid drawn top of tank to satisfy thermal load.

Christensen, D. L.↗

NASA NTRS1979

Durability of foam insulation for LH2 fuel tanks of future subsonic transports

Organic foams were tested to determine their suitability for insulating liquid hydrogen tanks of subsonic aircraft. The specimens, including nonreinforced foams and foams with chopped glass reinforcements, flame retardants, and vapor barriers, were scaled to simulate stress conditions in large tanks. The tests were conducted within aluminum tank compartments filled with liquid hydrogen and the boil-off rate was used as the criterion of thermal performance. It was found that while all insulations deteriorated with increased cycles, two nonreinforced polyurethane foams showed no structural deterioration after 4200 thermal cycles (equivalent to 15 years of airline service). It was also found that fiberglass reinforcement and flame retardants impaired thermal performance and reduced useful life of the foams. Vapor barriers enhanced structural integrity without any deterioration in thermal properties.

Sharpe, E. L.↗

NASA NTRS1980

Space Shuttle External Tank Project status

The External Tank Project is reviewed with emphasis on the DDT&E and production phases and the lightweight tank development. It is noted that the DDT&E phase is progressing well with the structural and ground vibration test article programs complete, the propulsion test article program progressing well, and the component qualification and verification testing 92% complete. New tools and facilities are being brought on line to support the increased build rate for the production phase. The lightweight tank, which will provide additional payload in orbit, is progressing to schedule with first delivery in early 1982.

Davis, R. M.↗

NASA NTRS1981

Fracture control plan for propellant and pressurant tanks

To assure the functional integrity of the GLL-RPM fuel and pressurized gas tank, all activities during entire lifetime of the tank, from manufacture to the end of the mission, must be monitored. Specifications are given for all procedures which influence the tank structure including design, manufacture, cleaning, test operations, and storage. Tests to be conducted to demonstrate that requirements of the fracture control plan are satisfied include static tests, cyclic load tests, proof tests, He-leak test, and acceptance tests.

Source record↗

NASA NTRS1981

Measurement of forces due to liquid motion in a propellant tank

This paper presents the results of a study to develop an analytical model capable of predicting the forces acting on a tank caused by large-amplitude propellant motion. This effort contributed to an analysis of the influence of propellant dynamics on separation of the External Tank from the space shuttle orbiter. This paper is concerned with an experimental investigation that aided in development and verification of the analytical model. A scaling approach was developed that allowed the liquid motion to be simulated in subscale tanks. Liquid reorientation forces were measured using two test systems. One operated in the low-gravity environment produced in a drop tower and the second operated aboard the KC-135 'zero-g' test aircraft. The manner of liquid motion, influence of various factors, and the measured forces are discussed.

Tegart, J. R.↗

NASA NTRS1983

Heated Aluminum Tanks Resist Corrosion

Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.

Johnson, L. E.↗

NASA NTRS1981

Experimental Study of Fuel Heating at Low Temperatures in a Wing Tank Model, Volume 1

Scale model fuel heating systems for use with aviation hydrocarbon fuel at low temperatures were investigated. The effectiveness of the heating systems in providing flowability and pumpability at extreme low temperature when some freezing of the fuel would otherwise occur is evaluated. The test tank simulated a section of an outer wing tank, and was chilled on the upper and lower surfaces. Turbine engine lubricating oil was heated, and recirculating fuel transferred the heat. Fuels included: a commercial Jet A; an intermediate freeze point distillate; a higher freeze point distillate blended according to Experimental Referee Broadened Specification guidelines; and a higher freeze point paraffinic distillate used in a preceding investigation. Each fuel was chilled to selected temperature to evaluate unpumpable solid formation (holdup). Tests simulating extreme cold weather flight, without heating, provided baseline fuel holdup data. Heating and recirculating fuel increased bulk temperature significantly; it had a relatively small effect on temperature near the bottom of the tank. Methods which increased penetration of heated fuel into the lower boundary layer improved the capability for reducing holdup.

Stockemer, F. J.↗

NASA NTRS1981

Study of liquid slosh in the tracking and data relay satellite hydrazine tanks

An experimental study was conducted to provide data for evaluation of the parameters for an analytical mechanical model representation of liquid/interface dynamics in the TDRSS propellant tanks. Models were developed for two liquid-under ullage (forward tank) configurations and for one liquid-over-ullage (aft tank) configuration. However, additional test runs were conducted with liquids of different densities in both cases to allow separation of bladder stiffness and gravity effects under various simulated steady acceleration conditions. Both static and dynamic parameters are evaluated to provide a good prediction of observed results.

Kana, D. D.↗

NASA NTRS1983

High-Speed Machining (HSM) of Space Shuttle External Tank (ET) panels

The External Fuel Tank (ET) of the Space Shuttle is not recovered after launch and a new one must be provided for each launch. Currently, the external ""skin'' panels of the tank are produced by machining from solid wrought 2219-T87 aluminum plate stock approximately 1-3/4 inch thick. The reduction of costs in producing External Fuel Tank panels is obviously of increasing production rates and decreasing costs of the panels through the application of high-speed machining (HSM) techniques was conducted.

Miller, J. A.↗

NASA NTRS1983

Test program to demonstrate the stability of hydrazine in propellant tanks

The suitability of stainless steels and Inconel for long-term hydrazine propellant-storage tanks is investigated. Rectangular coupon samples cut from propellent tanks were sealed with a measured amount of hydrazine in glass capsules, stored at 43 or 60 C, and removed after 6 to 24 months, when corrosion of the coupon and decomposition of the hydrazine was determined, and SEM and electron spectroscopy were performed on some coupons. Corrosion was found to be unmeasurably low for all the coupons, and hydrazine decomposition produced less than 1.0 cu cm of gas per sq cm of wetted surface per year, except in those few cases when catalysis or contamination were detected. Especially good stability was observed for type 304L stainless steel. The decomposition rates determined in the coupon tests are confirmed by preliminary results of actual tank storage trials.

Moran, C. M.↗

NASA NTRS1984

Effect of external pressure environment on the internal noise level due to a source inside a cylindrical tank

A small cylindrical tank was used to study the effect on the noise environment within a tank of conditions of atmospheric (sea level) pressure or vacuum environments on the exterior. Experimentally determined absorption coefficients were used to calculate transmission loss, transmissibility coefficients and the sound pressure (noise) level differences in the interior. The noise level differences were also measured directly for the two exterior environments and compared to various analytical approximations with limited agreement. Trend study curves indicated that if the tank transmission loss is above 25 dB, the difference in interior noise level between the vacuum and ambient pressure conditions are less than 2 dB.

Clevenson, S. A.↗

NASA NTRS1984

Space Shuttle reaction control subsystem propellant tank masked screen test

During final development testing of the Space Shuttle Reaction Control Subsystem propellant tanks, a problem with pressure transients in the system was uncovered. Due to the nature of the tanks, performance tests to determine the impact of the transients on the expulsion efficiency of the tanks could not directly simulate the actual conditions which would be present in a low-gravity environment. However, by masking or covering various segments of the propellant acquisition device, a good simulation of a low-gravity environment was achieved in ground testing.

Henderson, J. B.↗

NASA NTRS1986

Fuel Gage for Sloshing Tanks

New gage accurately measures fuel remaining in moving, or sloshing, tank. Measures tank air (or other gas) pressure and time required for pressure to change from one preselected level to another. Time measurement directly proportional to volume of air. Data processor computes relative volumes of air and fuel in tank.

Garner, H. D.↗