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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 NTRS2017

The Potential for Health Monitoring in Expandable Space Modules: The Bigelow Expandable Activity Module on the ISS

Expandable modules for use in space and on the Moon or Mars offer a great opportunity for volume and mass savings in future space exploration missions. This type of module can be compressed into a relatively small shape on the ground, allowing them to fit into space vehicles with a smaller cargo/fairing size than a traditional solid, metallic structure based module would allow. In April 2016, the Bigelow Expandable Activity Module (BEAM) was berthed to the International Space Station (ISS). BEAM is the first human-rated expandable habitat/module to be deployed and crewed in space. BEAM is a NASA managed ISS payload project in partnership with Bigelow Aerospace. BEAM is intended to stay attached to ISS for an operational period of 2 years to help advance the technology readiness for future expandable modules. BEAM has been instrumented with a suite of space flight certified sensors systems which will help characterize the module's performance for thermal, radiation shielding and impact monitoring against potential Micro Meteoroid/Orbital Debris (MM/OD) providing fundamental information on the BEAM environment for potential health monitoring requirements and capabilities. This paper will provide an overview of how the sensors/instrumentation systems were developed, tested, installed and an overview of the current sensor system operations. It will also discuss how the MM/OD impact detection system referred to as the Distributed Impact Detection System (DIDS) data is being processed and reviewed on the ground by the principle investigators.

Wells, Nathan D.↗
NASA NTRS1981

Transfer of line radiation in differentially expanding atmospheres. VI The plane parallel atmosphere with expanding and contracting regions

The non-LTE radiative transfer problem for a two level atom with complete redistribution over a Doppler profile is solved for a plane parallel slab (overlying a radiating photosphere) that has a velocity field which rises symmetrically from zero at either face to a central maximum. Since the velocity gradient reverses, distant layers of the slab become coupled by radiation that jumps intervening layers. The Feautrier method is used, but an iterative variant is also employed as a check in cases where poorly conditioned matrices are encountered. Approximations are developed to explain some of the principal features. It is found that the source function S tends to have two plateaus with values near 2/3 I sub 0 and 1/3 I sub 0, where I sub 0 is the photospheric continuum incident from below; the larger value lies nearer the photosphere. The upper layers sometimes exhibit a rise in S owing to interconnection by radiation to the base. It is noted that the radiation force is largest at the two faces and the midplane. Some line profiles are found to have unusually steep absorptions at rest frequency because of the low excitation in the uppermost, stationary layers.

Noerdlinger, P. D.↗
NASA NTRS1959

Experimental Investigation of Expanded Duct Sections and Screens for Reducing FLow Distortions at Subsonic Flows

An investigation of expanded duct sections and the effect of their design parameters on flow distortion over a duct Mach number range of 0.19 to 0.67 was conducted in the small tunnel facility of the Lewis Research Center. The parameters investigated were: (1) entrance angle of expanded section, (2) length of expanded section, (3) area ratio of expanded section, (4) location of expanded section relative to the engine face, and (5) the use of screens of varying solidities and mesh. Expansion half-angles of deg, 15 deg, and 30 deg reduced the total-pressure distortions induced in the duct. The larger expansion angles reduced circumferential distortion more effectively than radial distortion. However, the half-angle of 15 deg appeared to be optimum for reducing both radial and circumferential distortions while still maintaining a high total-pressure recovery. Increasing the expanded-section area ratio and increasing the expanded-section lengths with-the 150 expansion half-angle led to less total-pressure distortion with no appreciable loss in pressure recovery. Screens incorporated in the expanded section indicated that 22.2-percent- solidity screens decreased distortion still further.while 37.3-percent- solidity screens generally increased distortion above that of a constant- area duct incorporating the same solidity screen.

Chiccine, Bruce G.↗
NASA NTRS1985

An experimental reciprocating expander for cryocooler application

An experimental reciprocating expander was designed with features appropriate for cryocooler cycles. The expander has a displacer piston, simple valves, and a hydraulic/pneumatic stroking mechanism. The expander has a valve in head configuration with the valves extending out the bottom of the vacuum enclosure while the piston extends out the top. The expander was tested using a CTI 1400 liquefier to supply 13 atm in the temperature range 4.2 to 12 K. Expander efficiency was measured in the range 84 to 93% while operating the apparatus as a supercritical wet expander and in the range 91 to 93% aa a single phase expander. The apparatus can also be modified to operate as a compressor for saturated helium vapor.

Minta, M.↗
NASA NTRSDate not supplied

Modal Test and Model Correlation of NASA Plum Brook Station Mechanical Vibration Facility Head Expander –Lessons Learned from the Perspective of an Early-Career Engineer

In preparation for the Sierra Nevada Corporation’s (SNC) Dream Chaser spacecraft vibration test campaign at the Mechanical Vibration Facility (MVF) at NASA Plum Brook Station (PBS) in Sandusky, Ohio, a test-verified model of MVF is needed in order to be able to perform accurate pretest analysis used for determining response limits and abort levels. MVF was designed to vibration test MPCV Orion and was used to perform the system level vibration test of the European Service Module Structural Test Article (E-STA) in 2016. MVF is comprised of an 18 ft diameter annulus table that is driven with sixteen hydraulic vertical actuator assemblies and four hydraulic horizontal actuator assemblies, which allow it to perform single axis vibration testing in the vertical axis and in each of the two orthogonal horizontal axes without the need for reconfiguring the test article. A head expander for the MVF Table has been designed and built that fills in the center opening providing a continuous flat mounting surface with a maximum diameter of 16.25feet that expands the vibration testing capabilities of MVF. The MVF Table with this head expander will be used during the SNC Dream Chaser spacecraft vibration test campaign. Therefore, a critical element in a test-verified model of the MVF will be a test correlated finite element model (FEM) of the head expander. To obtain this, engineers from the Structural Dynamics Lab (SDL) at NASA Glenn Research Center (GRC) in Cleveland, Ohio performed a modal pretest analysis, conducted a modal test in July 2019, and most recently correlated the head expander finite element model to the modal test data up to 300 Hz. From the initial test preparations to the final delivery of a correlated finite element model, all efforts mentioned were led by the same early-career engineers at NASA GRC. From the viewpoint of an early-career engineer, lessons learned about modal pretest analysis, modal testing, and finite element model correlation of the MVF Table expander head will be presented and discussed. This will include the importance of understanding the limitations of using uncorrelated finite element models in the modal pretest analysis and planning, the importance of orthogonality metrics in judging adequacy and accuracy of test mode shapes, and the importance of having the FEM match the as built hardware in the model correlation effort.

Emma L Pierson↗
NASA NTRS1977

The helical screw expander evaluation project

A positive-displacement helical-screw expander of the Lysholm type has been adapted for geothermal service and successfully demonstrated in a 50 kW prototype power system. Evaluation of the expander by tests of a new model in a 1 MW power system under wellhead conditions in selected liquid-dominated geothermal fields is proposed. The objectives are to determine the performance characteristics of the expander and power system over a broad range of operating conditions and also to examine the concept of wellhead power plants. Throttling and fractionation of the fluids from the test wells is planned to simulate a wide range of wellhead pressures and steam fractions. Variation in the expander exhaust pressure is also planned. The investigation will include expander efficiency, corrosion, erosion, scale formation and control, and endurance testing. Interaction studies with the wells and an electric grid are also proposed.

Mckay, R. A.↗
NASA NTRS1980

Expanded interleaved solid-state memory for a wide bandwidth transient waveform recorder

An interleaved, solid state expanded memory for a 100 MHz bandwidth waveform recorder is described. The memory development resulted in a significant increase in the storage capacity of a commercially available recorder. The motivation for the memory expansion of the waveform recorder, which is used to support in-flight measurement of the electromagnetic characteristics of lightning discharges, was the need for a significantly longer data window than that provided by the commercially available unit. The expanded recorder provides a data window that is 128 times longer than the commercial unit, while maintaining the same time resolution, by increasing the storage capacity from 1024 to 131 072 data samples. The expanded unit operates at sample periods as small as 10 ns. Sampling once every 10 ns, the commercial unit records for about 10 microseconds before the memory is filled, whereas, the expanded unit records for about 1300 microseconds. A photo of the expanded waveform recorder is shown.

Thomas, R. M., Jr.↗
NASA NTRS1983

Screw expander for light duty diesel engines

Preliminary selection and sizing of a positive displacement screw compressor-expander subsystem for a light-duty adiabatic diesel engine; development of a mathematical model to describe overall efficiencies for the screw compressor and expander; simulation of operation to establish overall efficiency for a range of design parameters and at given engine operating points; simulation to establish potential net power output at light-duty diesel operating points; analytical determination of mass moments of inertia for the rotors and inertia of the compressor-expander subsystem; and preparation of engineering layout drawings of the compressor and expander are discussed. As a result of this work, it was concluded that the screw compressor and expander designed for light-duty diesel engine applications are viable alternatives to turbo-compound systems, with acceptable efficiencies for both units, and only a moderate effect on the transient response.

Source record↗
NASA NTRS1984

International test and demonstration of a 1-MW wellhead generator: Helical screw expander power plant

A 1-MW wellhead generator was tested in 1980, 1981, and 1982 by Mexico, Italy, and New Zealand at Cerro Prieto, Cesano, and Broadlands, respectively. The total flow helical screw expander portable power plant, Model 76-1, had been built for the U.S. Government and field-tested in Utah, USA, in 1978 and 1979. The expander had oversized internal clearances designed for self-cleaning operation on fluids that deposit adherent scale normally detrimental to the utiliation of liquid dominated fields. Conditions with which the expander was tested included inlet pressures of 64 to 220 psia, inlet qualities of 0% to 100%, exhaust pressures of 3.1 to 40 psia, electrial loads of idle and 110 to 933 kW, electrical frequencies of 50 and 60 Hz, male rotor speeds of 2500 to 4000 rpm, and fluid characteristics to 310,000 ppm total dissolved solids and noncondensables to 38 wt % of the vapor. Some testing was done on-grid. Typical expander isentropic efficiency was 40% to 50% with the clearances not closed, and 5 percentage points or more higher with the clearances partly closed. The expander efficiency increased approximately logarithmically with shaft power for most operations, while inlet quality, speed, and pressure ratio across the machine had only small effects. These findings are all in agreement with the Utah test results.

Mckay, R. A.↗
NASA NTRS2010

Intelligent Flexible Materials for Space Structures: Expandable Habitat Engineering Development Unit

Expandable habitable elements are an enabling technology for human exploration in space and on planetary surfaces. Large geometries can be deployed from a small launch volume, allowing greater mission capability while reducing mass and improving robustness over traditional rigid shells. This report describes research performed by ILC Dover under the Intelligent Flexible Materials for Space Structures program on the design and manufacture of softgoods for LaRC's Expandable Habitat Engineering Development Unit (EDU). The EDU is a full-scale structural test article of an expandable hybrid habitat, integrating an expandable softgoods center section with two rigid end caps. The design of the bladder, restraint layer and a mock-up Thermal Micrometeoroid Cover is detailed together with the design of the interface hardware used to attach them to the end caps. The integration and design of two windows and a floor are also covered. Analysis was performed to study the effects of the open weave design, and to determine the correct webbing and fabric configuration. Stress analyses were also carried out on the interfaces between the softgoods and the end caps and windows. Testing experimentally determined the strength of the fabric and straps, and component testing was used to proof several critical parts of the design. This program established new manufacturing and design techniques that can be applied to future applications in expandable structures.

Hinkle, Jon↗
NASA NTRS1973

Expandable space frames

Expandable space frames having essentially infinite periodicity limited only by practical considerations, are described. Each expandable space frame comprises a plurality of hinge joint assemblies having arms that extend outwardly in predetermined symmetrically related directions from a central or vertex point. The outer ends of the arms form one part of a hinge point. The outer expandable space frame also comprises a plurality of struts. The outer ends of the struts from the other part of the hinged joint. The struts interconnect the plurality of hinge point in sychronism, the spaceframes can be expanded or collapsed. Three-dimensional as well as two-dimensional spaceframes of this general nature are described.

Schoen, A. H.↗
NASA NTRS1974

Vibrational relaxation in expanding N2 and air

New N2 vibrational temperature data, obtained in expanding N2 and air using the electron beam technique, are analyzed permitting the vibrational relaxation times to be determined as a function of temperature. In addition, the effects on N2 vibrational relaxation times of direct vibrational energy transfer between N2 and H2O, between N2 and O2, and between N2 and free electrons introduced from arc contaminants are analyzed. The vibrational relaxation times determined from the present measurements agree with those measured in the expanding flows of shock tunnels and impact tubes. These expanding data also agree with relaxation times observed in acoustical resonant cavities where alternating compressions and expansions take place. The relaxation times in expanding flows (vib-tran exchange process) are found to be approximately 50 times faster than those measured in the compressing flow of shock tubes (tran-vib exchange process). This evidence strongly supports the concept that one relaxation time distribution cannot be applied to both exchange processes.

Sebacher, D. I.↗
NASA NTRS1991

Advanced expander test bed program

The Advanced Expander Test Bed (AETB) is a key element in NASA's Chemical Transfer Propulsion Program for development and demonstration of expander cycle oxygen/hydrogen engine technology component technology for the next space engine. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced missions focused components and new health monitoring techniques. The split-expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

Masters, A. I.↗
NASA NTRS1992

Advanced expander test bed engine

The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

Mitchell, J. P.↗
NASA NTRS1993

Advanced expander test bed program

The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust. Contract work began 27 Apr. 1990. During 1992, a major milestone was achieved with the review of the final design of the oxidizer turbopump in Sep. 1992.

Riccardi, D. P.↗
NASA NTRS2011

HEXPANDO Expanding Head for Fastener-Retention Hexagonal Wrench

The HEXPANDO is an expanding-head hexagonal wrench designed to retain fasteners and keep them from being dislodged from the tool. The tool is intended to remove or install socket-head cap screws (SHCSs) in remote, hard-to-reach locations or in circumstances when a dropped fastener could cause damage to delicate or sensitive hardware. It is not intended for application of torque. This tool is made of two assembled portions. The first portion of the tool comprises tubing, or a hollow shaft, at a length that gives the user adequate reach to the intended location. At one end of the tubing is the expanding hexagonal head fitting with six radial slits cut into it (one at each of the points of the hexagonal shape), and a small hole drilled axially through the center and the end opposite the hex is internally and externally threaded. This fitting is threaded into the shaft (via external threads) and staked or bonded so that it will not loosen. At the other end of the tubing is a knurled collar with a through hole into which the tubing is threaded. This knob is secured in place by a stop nut. The second assembled portion of the tool comprises a length of all thread or solid rod that is slightly longer than the steel tubing. One end has a slightly larger knurled collar affixed while the other end is tapered/pointed and threaded. When the two portions are assembled, the all thread/rod portion feeds through the tubing and is threaded into the expanding hex head fitting. The tapered point allows it to be driven into the through hole of the hex fitting. While holding the smaller collar on the shaft, the user turns the larger collar, and as the threads feed into the fitting, the hex head expands and grips the SHCS, thus providing a safe way to install and remove fasteners. The clamping force retaining the SHCS varies depending on how far the tapered end is inserted into the tool head. Initial tests of the prototype tool, designed for a 5 mm or # 10SHCS have resulted in up to 8 lb (.35.6 N) of pull force to dislodge the SHCS from the tool. The tool is designed with a lead-in angle from the diameter of the tubing to a diameter the same as the fastener head, to prevent the fastener head from catching on any obstructions encountered that could dislodge the fastener during retrieval.

Bishop, John↗
NASA NTRS2012

Materials, Structures and Manufacturing: An Integrated Approach to Develop Expandable Structures

Membrane dominated space structures are lightweight and package efficiently for launch; however, they must be expanded (deployed) in-orbit to achieve the desired geometry. These expandable structural systems include solar sails, solar power arrays, antennas, and numerous other large aperture devices that are used to collect, reflect and/or transmit electromagnetic radiation. In this work, an integrated approach to development of thin-film damage tolerant membranes is explored using advanced manufacturing. Bio-inspired hierarchical structures were printed on films using additive manufacturing to achieve improved tear resistance and to facilitate membrane deployment. High precision, robust expandable structures can be realized using materials that are both space durable and processable using additive manufacturing. Test results show this initial work produced higher tear resistance than neat film of equivalent mass. Future research and development opportunities for expandable structural systems designed using an integrated approach to structural design, manufacturing, and materials selection are discussed.

Belvin, W. Keith↗