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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Evaluation of propellant tank insulation concepts for low-thrust chemical propulsion systems

An analytical evaluation of cryogenic propellant tank insulations for liquid oxygen/liquid hydrogen low-thrust 2224N (500 lbf) propulsion systems (LTPS) was conducted. The insulation studied consisted of combinations of N2-purged foam and multilayer insulation (MLI) as well as He-purged MLI-only. Heat leak and payload performance predictions were made for three Shuttle-launched LTPS designed for Shuttle bay packaged payload densities of 56 kg/cu m, 40 kg/cu m and 24 kg/cu m. Foam/MLI insulations were found to increase LTPS payload delivery capability when compared with He-purged MLI-only. An additional benefit of foam/MLI was reduced operational complexity because Orbiter cargo bay N2 purge gas could be used for MLI purging. Maximum payload mass benefit occurred when an enhanced convection, rather than natural convection, heat transfer was specified for the insulation purge enclosure. The enhanced convection environment allowed minimum insulation thickness to be used for the foam/MLI interface temperature selected to correspond to the moisture dew point in the N2 purge gas. Experimental verification of foam/MLI benefits was recommended. A conservative program cost estimate for testing a MLI-foam insulated tank was 2.1 million dollars. It was noted this cost could be reduced significantly without increasing program risk.

Kramer, T.↗
NASA NTRS1984

Evaluation of propellent tank insulation concepts for low-thrust chemical propulsion systems: Executive summary

Cryogenic propellant tank insulations or liquid oxygen/liquid hydrogen low-thrust 2224N (500 lbf) propulsion systems (LTPS) were assessed. The insulation studied consisted of combinations of N2-purged foam and multilayer insulation (MLI) as well as He-purged MLI-only. Heat leak and payload performance predictions were made for three shuttle-launched LTPS designed for shuttle bay packaged payload densities of 56 kg cu/m (3.5 lbm/cu ft), 40 kg/cu m (2.5 lbm/cu ft) and 24 kg/cu m (1.5 lbm/cu ft). Foam/MLI insulations were found to increase LTPS payload delivery capability when compared with He-purged MLI-only. An additional benefit of foam/MLI was reduced operational complexity because orbiter cargo bay N2 purge gas could be used for MLI purging. Maximum payload mass benefit occurred when an enhanced convection, rather than natural convection, heat transfer was specified for the insulation purge enclosure. The enhanced convection environment allowed minimum insulation thickness to be used for the foam/MLI interface temperature selected to correspond to the moisture dew point in the N2 purge gas. Experimental verification of foam/MLI benefits was recommended. A conservative program cost estimate for testing a MLI-foam insulated tank was 2.1 million dollars. This cost could be reduced significantly without increasing program risk.

Kramer, T.↗
NASA NTRS1974

Triple balance test of the PRR baseline space shuttle configuration on a .004 scale model of the MCR 0074 orbiter configuration in the MSFC 14 x 14 inch Trisonic Wind Tunnel (TWT 570) IA31F(B), volume 1

A wind tunnel force and moment test of the space shuttle launch vehicle was conducted. The wind tunnel model utilized a triple balance such that component aerodynamics of the orbiter, external tank, and solid rocket booster was obtained. The test was conducted at an angle of attack range from -10 deg to 10 deg, and angle of sideslip range from -10 deg to 10 deg, and a Mach number range from 0.6 to 4.96. Simulation parameters to be used in future launch vehicle wind tunnel tests were investigated. The following were included: (1) effect of orbiter -ET attach hardware; (2) model attachment (spacer) effects; (3) effects of grit on model leading surfaces; and (4) model misalignment effects. The effects of external tank nose shape was studied by investigating five different nose configurations. Plotted and tabulated data is reported.

Ramsey, P. E.↗
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 NTRS1985

Dynamics of liquid sloshing in upright and inverted bladdered tanks

A system identification methodology was used to examine the dynamics of liquid sloshing in the upright and inverted bladdered hydrazine tanks of the Tracking and Data Relay Satellite, (TDRS) and to evaluate the effects of bladder stiffness on the sloshing parameters. Mechanical models of the two systems were developed using the numerical values derived from static stability tests and from slosh frequency response tests of a full-size model tank fitted with a prototype bladder. For the upright tank (liquid below the bladder) a modified conventional pendulum was used. In the inverted tank (liquid above the bladder) where sloshing is unconventional due to the highly nonsymmetrical orientation of the liquid held by the bladder, a mechanical model using an inverted pendulum which is able to undergo small oscillations as well as large reorientations was necessary. Both thrusting and low-gravity conditions are considered.

Dodge, F. T.↗
NASA NTRS2005

Microwave and Millimeter Wave Testing for the Inspection of the Space Shuttle Spray on Foam Insulations (SOFI) and the Acreage Heat Tiles

The utility of microwave and millimeter wave nondestructive testing and evaluation (NDT&E) methods, for testing the Space Shuttle's external he1 tank spray on foam insulation (SOFI) and the acreage heat tiles has been investigated during the past two years. Millimeter wave NDE techniques are capable of producing internal images of SOFI. This paper presents the results of testing several diverse panels with embedded voids and debonds at millimeter wave frequencies. Additionally, the results of testing a set of heat tiles are also presented. Finally, the attributes of these methods as well as the advantageous features associated with these systems are also provided.

Zoughi, R.↗
NASA NTRS1973

Acquisition/expulsion system for earth orbital propulsion system study. Volume 2: Cryogenic design

Detailed designs were made for three earth orbital propulsion systems; (1) the space shuttle (integrated) OMS/RCS, (2) the space shuttle (dedicated) OMS (LO2), and (3) the space tug. The preferred designs from the integrated OMS/RCS were used as the basis for the flight test article design. A plan was prepared that outlines the steps, cost, and schedule required to complete the development of the prototype DSL tank and feedline (LH2 and LO2) systems. Ground testing of a subscale model using LH2 verified the expulsion characteristics of the preferred DSL designs.

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NASA NTRS1975

Fracture control method for composite tanks with load sharing liners

The experimental program was based on the premise that the plastic sizing cycle, which each pressure vessel is subjected to prior to operation, acts as an effective proof test of the liner, screening out all flaws or cracks larger than a critical size. In doing so, flaw growth potential is available for cyclic operation at pressures less than the sizing pressure. Static fracture and cyclic life tests, involving laboratory type specimens and filament overwrapped tanks, were conducted on three liner materials: (1) 2219-T62 aluminum, (2) Inconel X750 STA, and (3) cryoformed 301 stainless steel. Variables included material condition, thickness, flaw size, flaw shape, temperature, sizing stress level, operating stress level and minimum-to-maximum operating stress ratio. From the empirical data base obtained, a procedure was established by which the service life of composite tanks with load sharing liners could be guaranteed with a high degree of confidence.

Bixler, W. D.↗
NASA NTRS1984

Ion thruster system (8-cm) cyclic endurance test

This report describes the qualification test of an Engineering-Model 5-mN-thrust 8-cm-diameter mercury ion thruster which is representative of the Ion Auxiliary Propulsion System (IAPS) thrusters. Two of these thrusters are scheduled for future flight test. The cyclic endurance test described herein was a ground-based test performed in a vacuum facility with a liquid-nitrogen-cooled cryo-surface and a frozen mercury target. The Power Electronics Unit, Beam Shield, Gimal, and Propellant Tank that were used with the thruster in the endurance test are also similar to those of the IAPS. The IAPS thruster that will undergo the longest beam-on-time during the actual space test will be subjected to 7,055 hours of beam-on-time and 2,557 cycles during the flight test. The endurance test was successfully concluded when the mercury in the IAPS Propellant Tank was consumed. At that time, 8,471 hours of beam-on-time and 599 cycles had been accumulated. Subsequent post-test-evaluation operations were performed (without breaking vacuum) which extended the test values to 652 cycles and 9,489 hours of beam-on-time. The Power Electronic Unit (PEU) and thruster were in the same vacuum chamber throughout the test. The PEU accumulated 10,268 hr of test time with high voltage applied to the operating thruster or dummy load.

Dulgeroff, C. R.↗
NASA NTRS1988

Design, development, and test of Shuttle/Centaur G-prime cryogenic tankage thermal protection systems

The thermal protection systems (TPS) for the Shuttle/Centaur were designed to provide fail-safe thermal protection during prelaunch, launch ascent, and on-orbit operations as well as during potential abort, where the Shuttle and Centaur would return to earth. The TPS selected used a helium-purged polyimide foam beneath three radiation shields for the liquid-hydrogen (LH2) tank and radiation shields only for the liquid-oxygen (LO2) tank. A double-walled vacuum bulkhead separated the two tanks. The LH2 tank had one 1.9 cm-thick layer of foam on the forward bulkhead and two layers on the larger-area sidewall. Full scale tests of the flight vehicle in a simulated Shuttle cargo bay gave total prelaunch heating rates of 29.5 and 12.9 kW for the LH2 and LO2 tanks, respectively. Calorimeter tests on a representative sample of the LH2 tank sidewall TPS indicated that the measured unit heating one would rapidly decrease from the prelaunch rate of about 300 W/sq m to a desired rate less than 4 W/sq m once on-orbit.

Macneil, Peter N.↗
NASA NTRS1965

Weld leaks rapidly and safely detected

Test method detects leaks that occur during hydrostatic pressure testing of welded joints in metal tanks. A strip of aluminum foil and a strip of water-soluble paper are placed over the weld. A voltage applied between the tank wall and the foil strip is monitored to detect a decrease in ohmic resistance caused by water leakage into the paper layer.

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NASA NTRS1974

Draw forming of scale shuttle external tank dome gores

The process for manufacturing external tank dome gores is discussed. The test fixture and test procedure are described. The characteristics of the draw forming die are analyzed. The specific subjects included are: (1) forming, (2) trimming, (3) cleaning, and (4) heat treatment.

Garfield, G.↗
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.

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NASA NTRS1983

NASA redox storage system development project

The operating temperature was raised from 25 C to 65 C, which enhanced the kinetics of the chromium electrode charging reactions. The design of the auxiliary electrochemical cell, which is used to keep both reactants at the same state of charge, was modified, leading to better and more stable performance. Preliminary testing has shown that the four tank mode of operation improves energy efficiency as much as 5 percentage points over the conventional two tank mode. Another variation in operating mode, the use of mixed reactants, potentially offers several very attractive advantages. Preliminary reactant cost studies lend further weight to the feasibility of the mixed reactant concept. Electrode studies show that reproducibility of performance is very dependent on the pyrolysis temperature at which the carbon/graphite felt substrate is formed. Membrane development work continued to concentrate on cost reduction and the enhancement of resistivity and selectivity.

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NASA NTRS1986

Computer code for gas-liquid two-phase vortex motions: GLVM

A computer program aimed at the phase separation between gas and liquid at zero gravity, induced by vortex motion, is developed. It utilizes an explicit solution method for a set of equations describing rotating gas-liquid flows. The vortex motion is established by a tangential fluid injection. A Lax-Wendroff two-step (McCormack's) numerical scheme is used. The program can be used to study the fluid dynamical behavior of the rotational two-phase fluids in a cylindrical tank. It provides a quick/easy sensitivity test on various parameters and thus provides the guidance for the design and use of actual physical systems for handling two-phase fluids.

Yeh, T. T.↗
NASA NTRS1990

Effect of detailed surface geometry on riblet drag reduction performance

A comparison is made of the effect of small changes in v-groove geometry, for several riblet films applicable for drag reduction to commercial transport aircraft, whose nominal v-groove dimension is of the order of 0.002 inch. The films were tested in a water towing-tank facility. The results obtained indicate that small riblet peak geometry variations can result in a deterioration of riblet drag-reduction efficacy of as much as 40 percent, while interriblet valley curvature was found not to be critical to riblet performance.

Walsh, Michael J.↗