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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 415 records · Page 23

Floating baffle to improve efficiency of liquid transfer from tanks

A floating baffle is described which rides up and down on a vertical shaft over a drain in a tank as the liquid level within the tank varies. When the baffle is in the raised position, the liquid is allowed to flow out of the drain at an unrestricted rate. When the baffle is in the lowered position, pull-through of air or gas that is above the liquid is presented, which would interfere and reduce the flow of liquid from the tank.

Howard, F. S.↗

The analysis of the transient pressure response of the shuttle EPS-ECS cryogenic tanks with external pressurization systems

An analysis of transient pressures in externally pressurized cryogenic hydrogen and oxygen tanks was conducted and the effects of design variables on pressure response determined. The analysis was conducted with a computer program which solves the compressible viscous flow equations in two-dimensional regions representing the tank and external loop. The external loop volume, thermal mass, and heat leak were the dominant design variables affecting the system pressure response. No significant temperature stratification occurred in the fluid contained in the tank.

Barton, J. E.↗

Development of a fracture control method for composite tanks with load sharing liners

This experimental program was undertaken to establish a fracture control method for composite tanks with load sharing liners. Uniaxial specimens containing surface flaws were loaded to failure (static fractured) and cycled to failure and the results were compared with burst tests and cyclic life tests of composite tanks having surface flaws present in the load sharing metal liners. The liner materials investigated were Inconel X750 STA, 2219-T62 aluminum and cryostretched 301 stainless steel at room temperature and at 78 K (-320 F) in liquid nitrogen. Differences were observed in comparing the uniaxial and tank test results. These differences should be resolved if an adequate fracture control method is to be developed.

Bixler, W. D.↗

Evacuation areas for transportation accidents involving propellant tank pressure bursts

Evacuation areas are defined for those transportation accidents where volatile chemical propellant tanks are exposed to fire in the wreckage and eventually explode with consequent risks from fragments in surrounding populated areas. An evacuation area with a minimum radius of 600 m (2000 ft) is recommended to limit the statistical probability of fatality to one in 100 such accidents. The result was made possible by the derivation of a distribution function of distances reached by fragments from bursting chemical car tanks. Data concerning fragments was obtained from reports or tank car pressure bursts between 1958 and 1971.

Siewert, R. D.↗

Liquid sloshing in a tilted cylindrical tank.

Two distinct fundamental modes are shown to exist for liquid sloshing in a tilted cylindrical tank. The 'long' mode is excited by tank motions parallel to the long axis of the elliptical free surface, the 'short' mode by tank motions perpendicular to it. Experiments show that the natural frequencies of both modes decrease as the tilt increases, and the slosh damping decreases markedly with increased tilt for the long mode.

Dodge, F. T.↗

Effect of external tank nose shape on the Rockwell International space shuttle vehicle 3, integrated configuration (IA37B)

Tests of several tank nose shapes were conducted as a part of the investigation of configuration changes to reduce drag for the integrated vehicle. The effect on the integrated vehicle aerodynamic characteristics of several tank nose shapes was investigated. The tank nose shapes investigated were the 600 inch (baseline) and 1204 inch radius ogives, and the 600 inch ogive plus a spike 360 inches long and 12.0 inches in diameter. Data were obtained over a Mach number range of 0.6 through 4.96 and for angles-of-attack and sideslip from -10 through +10 degrees. The model used was the 0.004-scale integrated vehicle model number 34-OTS.

Allen, E. C.↗

Evacuation areas for transportation accidents involving propellant tank pressure bursts

Evacuation areas are defined for those transportation accidents where volatile chemical propellant tanks are exposed to fire in the wreckage and eventually explode with consequent risks from fragments in surrounding populated areas. An evacuation area with a minimum radius of 600 m is recommended to limit the statistical probability of fatality to one in 100 such accidents. The result of this study was made possible by the derivation of a distribution function of distances reached by fragments from bursting chemical car tanks. Data concerning fragments were obtained from reports of tank car pressure bursts between 1958 and 1971.

Siewert, R. D.↗

Abort separation study of a shuttle orbiter and external tank at hypersonic speeds

The effects of several parameters on the relative motions of a space shuttle orbiter design and its external tank were determined during staging for the return-to-launch-site abort mode. The parameters included angle of attack, dynamic pressure, flight-path angle, pitch rate, elevon effectiveness and the use of thrust applied to the tank. The relative positions of each component were determined by a separation trajectory computer program which incorporated data obtained in wind-tunnel tests with the orbiter and tank in proximity. These tests were conducted at Mach 10.3 in a continuous-flow hypersonic tunnel. All separation cases were initiated at a constant Mach number of 10 with an assumed sideslip angle of 0 deg.

Bernot, P. T.↗

Development of a remote sensing technique to study the hydrology of earth stock tanks on a semiarid watershed

The stock tanks considered are relatively small earthen reservoirs, built in tributary stream channels and drainageways. A remote sensing technique is developed for obtaining quantitative data on water levels and water losses from stock tanks. Details of the used approaches are discussed along with some difficulties which would have to be overcome in order to determine the effects of the stock tanks on stream flow.

Cluff, C. B.↗

Analysis of ECLSS performance during reentry after loss of one ammonia tank

An analysis was performed to determine whether, in case of a loss of one of the ammonia tanks, the Ammonia Boiler System can provide adequate heat rejection for the orbiter ECLSS during reentry. Results indicate that temperatures can be maintained as long as NH3 is available, but that one tank does not contain sufficient NH3 to complete all missions. A recommendation is made to investigate incorporation of onboard NH3 quantity calculations, and/or addition of a third NH3 tank.

Steines, G. J.↗

Transition heating rates obtained on a matted and isolated 0.006 scale model (41-OT) space shuttle orbiter and external tank in the NASA/LaRC variable density hypersonic tunnel (IH17)

Model information and data obtained from wind tunnel tests performed on a 0.006 scale model of the Rockwell International space shuttle orbiter and external tank in the 18 inch Variable Density Hypersonic Wind Tunnel (VDHT) at NASA Langley Research Center are presented. Tests were performed at a Mach number of 8.0 over a Reynolds Number range from 0.1 to 10.0 million per foot at 0 deg and -5 deg angle of attack and 0 deg sideslip angle. Transition heating rates were determined using thin skin thermocouples located at various locations on the orbiter and ET. The test was conducted in three stages: orbiter plus external tank (mated configuration); orbiter alone, and external tank alone. The effects of boundary layer trips were also included in the test sequence. The plotted results presented show the effect of configuration interference on the orbiter lower surface and on the ET. Tabulated data are given.

Cummings, J.↗

Evaluation of fluid behavior in spinning toroidal tanks

An experimental study was conducted to evaluate propellant behavior in spinning toroidal tanks that could be used in a retro-propulsion system of an advanced outer-planet Pioneer orbiter. Information on propellant slosh and settling and on ullage orientation and stability was obtained. The effects of axial acceleration, spin rate, spin rate change, and spacecraft wobble, both singly and in combination, were evaluated using a 1/8-scale transparent tank in one-g and low-g environments. Liquid loadings ranged from 5% to 96% full. The impact of a surface tension acquisition device was assessed. Testing simulated the behavior of F2/N2H4 and N2O4/MMH propellants. Results are presented which indicate no major fluid behavior problems would be encountered with any of the four propellants in the toroidal tanks of a spin-stabilized orbiter spacecraft.

Anderson, J. E.↗

Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

Namkoong, D.↗

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.↗

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.↗

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.↗

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.↗

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.↗