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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Single stage, low noise, advanced technology fan. Volume 5: Fan acoustics. Section 2: One-third octave data tabulations and selected narrowband traces

The raw-acoustic data corrected to standard day, from acoustic tests performed on a 0.508-scale fan vehicle of a 111,300 newton thrust, full-size engine, which has application on an advanced transport aircraft, are presented. The single-stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec to achieve the desired pressure ratio in a single-stage fan with low radius ratio, and to maintain adequate stall margin. The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise was accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels. The suppression goal of FAR 36-20 was not reached, but improvements in the technology of both front and aft fan-noise suppression were realized.

Jutras, R. R.↗
NASA NTRS1994

Electrochemical Technology for Oxygen Removal and Measurement in the CELSS Test Facility, Engineering Development Unit

The Life Support Flight Program is evaluating regenerative technologies, including those that utilize higher plants, as a means to reduce resupply over long duration space missions. Constructed to assist in the evaluation process is the CELSS Test Facility Engineering Development Unit (CTF-EDU) an environmentally closed (less than 1% mass and thermal leakage) technology test bed. This ground based fully functional prototype is currently configured to support crop growth, utilizing the power, volume and mass resources allocated for two space station racks. Sub-system technologies were selected considering their impact on available resources, their ability to minimize integration issues, and their degree of modularity. Gas specific mass handling is a key sub-system technology for both biological and physical/chemical life support technologies. The CTF-EDU requires such a system to accommodate non-linear oxygen production from crops, by enabling the control system to change and sustain partial pressure set points in the growth volume. Electrochemical cells are one of the technologies that were examined for oxygen handling in the CTF-EDU. They have been additionally considered to meet other regenerative life support functions, such as oxygen generation, the production of potable water from composite waste streams, and for having the potential to integrate life support functions with those of propulsion and energy storage. An oxygen removal system based on an electrochemical cell was chosen for the EDU due to it's low power, volume and mass requirements (10W, 0.000027 cu m, 4.5 kg) and because of the minimal number of integration considerations. Unlike it's competitors, the system doesn't require post treatments of its byproducts, or heat and power intensive regenerations, that also mandate system redundancy or cycling. The EDUs oxygen removal system only requires two resources, which are already essential to controlled plant growth: electricity and water. Additionally, the amount of oxygen that is removed from the EDU is directly proportional to the cell input current via Faraday's constant, potentially allowing for a mol/electron measurement of photosynthetic rate. The currently operative oxygen removal system has maintained reduced oxygen set points within the EDU, and preparation is underway to verify of the accuracy of electrochemical measurement of oxygen production and hence, photosynthesis. This paper examines the working principles of the electrochemical cell, outlines the overall design of the oxygen removal system and its integration with other EDU subsystems, and summarizes test results obtained over crop growth cycles in the CTF-EDU.

Drews, Michael E.↗
NASA NTRS1998

Cardiogenic oscillation phase relationships during single-breath tests performed in microgravity

We studied the phase relationships of the cardiogenic oscillations in the phase III portion of single-breath washouts (SBW) in normal gravity (1 G) and in sustained microgravity (microG). The SBW consisted of a vital capacity inspiration of 5% He-1.25% sulfurhexafluoride-balance O2, preceded at residual volume by a 150-ml Ar bolus. Pairs of gas signals, all of which still showed cardiogenic oscillations, were cross-correlated, and their phase difference was expressed as an angle. Phase relationships between inspired gases (e.g., He) and resident gas (n2) showed no change from 1 G (211 +/- 9 degrees) to microG (163 +/- 7 degrees). Ar bolus and He were unaltered between 1 G (173 +/- 15 degrees) and microG (211 +/- 25 degrees), showing that airway closure in microG remains in regions of high specific ventilation and suggesting that airway closure results from lung regions reaching low regional volume near residual volume. In contrast, CO2 reversed phase with He between 1 G (332 +/- 6 degrees) and microG (263 +/- 27 degrees), strongly suggesting that, in microG, areas of high ventilation are associated with high ventilation-perfusion ratio (VA/Q). This widening of the range of VA/Q in microG may explain previous measurements (G.K. Prisk, A.R. Elliott, H.J.B. Guy, J.M. Kosonen, and J.B. West J. Appl. Physiol. 79: 1290-1298, 1995) of an overall unaltered range of VA/Q in microG, despite more homogeneous distributions of both ventilation and perfusion.

Non-NASA Center↗
NASA NTRS2010

NASA Tech Briefs, May 2010

Topics covered include: Instrument for Analysis of Greenland's Glacier Mills Cryogenic Moisture Apparatus; A Transportable Gravity Gradiometer Based on Atom Interferometry; Three Methods of Detection of Hydrazines; Crossed, Small-Deflection Energy Analyzer for Wind/Temperature Spectrometer; Wavefront Correction for Large, Flexible Antenna Reflector; Novel Micro Strip-to-Waveguide Feed Employing a Double-Y Junction; Thin-Film Ferro Electric-Coupled Microstripline Phase Shifters With Reduced Device Hysteresis; Two-Stage, 90-GHz, Low-Noise Amplifier; A 311-GHz Fundamental Oscillator Using InP HBT Technology; FPGA Coprocessor Design for an Onboard Multi-Angle Spectro-Polarimetric Imager; Serrating Nozzle Surfaces for Complete Transfer of Droplets; Turbomolecular Pumps for Holding Gases in Open Containers; Triaxial Swirl Injector Element for Liquid-Fueled Engines; Integrated Budget Office Toolbox; PLOT3D Export Tool for Tecplot; Math Description Engine Software Development Kit; Astronaut Office Scheduling System Software; ISS Solar Array Management; Probabilistic Structural Analysis Program; SPOT Program; Integrated Hybrid System Architecture for Risk Analysis; System for Packaging Planetary Samples for Return to Earth; Offset Compound Gear Drive; Low-Dead-Volume Inlet for Vacuum Chamber; Simple Check Valves for Microfluidic Devices; A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions; Gimballing Spacecraft Thruster; Finned Carbon-Carbon Heat Pipe with Potassium Working Fluid; Lightweight Heat Pipes Made from Magnesium; Ceramic Rail-Race Ball Bearings; Improved OTEC System for a Submarine Robot; Reflector Surface Error Compensation in Dual-Reflector Antennas; Enriched Storable Oxidizers for Rocket Engines; Planar Submillimeter-Wave Mixer Technology with Integrated Antenna; Widely Tunable Mode-Hop-Free External-Cavity Quantum Cascade Laser; Non-Geiger-Mode Single-Photon Avalanche Detector with Low Excess Noise; Using Whispering-Gallery-Mode Resonators for Refractometry; RF Device for Acquiring Images of the Human Body; Reactive Collision Avoidance Algorithm; Fast Solution in Sparse LDA for Binary Classification; Modeling Common-Sense Decisions in Artificial Intelligence; Graph-Based Path-Planning for Titan Balloons; Nanolaminate Membranes as Cylindrical Telescope Reflectors; Air-Sea Spray Airborne Radar Profiler Characterizes Energy Fluxes in Hurricanes; Large Telescope Segmented Primary Mirror Alignment; and Simplified Night Sky Display System.

Source record↗
NASA NTRS1982

Low concentration ratio solar array for low Earth orbit multi-100kW application. Volume 2: Drawings

A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are provided.

Nalbandian, S. J.↗
NASA NTRS1972

An emergency survival suit

A thermally insulative inflatable garment designed specifically as a lightweight low storage volume emergency suit for subzero weather survival is reported. Testing confirms that the inflatable suit design satisfies the objectives for a subject standing at rest with environmental temperatures down to -450 F if the garment is inflated with Freon.

Curtis, D. L.↗
NASA NTRS1972

Plated wire memory subsystem

The work performed entailed the design, development, construction and testing of a 4000 word by 18 bit random access, NDRO plated wire memory for use in conjunction with a spacecraft imput/output unit and central processing unit. The primary design parameters, in order of importance, were high reliability, low power, volume and weight. A single memory unit, referred to as a qualification model, was delivered.

Reynolds, L.↗
NASA NTRS1974

Cyclic fatigue analysis of rocket thrust chambers. Volume 1: OFHC copper chamber low cycle fatigue

A three-dimensional finite element elasto-plastic strain analysis was performed for the throat section of a regeneratively cooled rocket combustion chamber. The analysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the chamber operating cycle. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen combustion chamber which was fatigue tested to failure. The computed strain range at typical chamber operating conditions was used in conjunction with oxygen-free, high-conductivity (OHFC) copper isothermal fatigue test data to predict chamber low-cycle fatigue life.

Miller, R. W.↗
NASA NTRS1974

Earth Observatory Satellite system definition study. Report 5: System design and specifications. Volume 7: Specification for EOS low cost readout station

The functional, performance, and design requirements for the Low Cost Readout Station (LCRS) which supports the Earth Observatory Satellite (EOS) data system are described. The basic LCRS consists of all hardware and software needed to acquire and track the EOS-A or EOS-B satellite and receive, record, process, and annotate the instrument data from the satellites. The LCRS also provides appropriate interfaces with the unique local user provided display and extractive processing equipment. The LCRS has the capability of acquiring image data from the EOS-A and the EOS-B satellites over a ground area defines by a 500 kilometer radius from the coordinates of the station. The LCRS is also capable of receiving and processing both, but not simultaneously, full five band Multispectral Scanner (MSS) image data and various modes of the Compacted Thematic (CTM) data.

Source record↗
NASA NTRS1975

Development of an automated potable water bactericide monitoring unit

A monitor unit has been developed that permits the direct determination of the level of elemental iodine, used for microbiological control, in a spacecraft potable water supply system. Salient features of unit include low weight, volume and maintenance requirements, complete automatic operation, no inflight calibration, no expendables (except electrical current) and high accuracy and precision. This unit is capable of providing a signal to a controller that, in turn, automatically adjusts the addition rate of iodine to the potable water system so that a predetermined level of iodine can be maintained. In addition, the monitor provides a reading whereby the crewman can verify that the proper amount of iodine (within a range) is present in the water. A development history of the monitor is presented along with its design and theory of operation. Also presented are the results generated through testing of the unit in a simulated Shuttle potable water system.

Walsh, J. M.↗
NASA NTRS1975

Landing pressure loads of the 140A/B space shuttle orbiter (model 43-0) determined in the Rockwell International low speed wind tunnel (OA69), volume 1

Wind tunnel tests of a 0.0405 scale model of the -1404A/B configuration of the Space Shuttle Vehicle Orbiter are presented. Pressure loads data were obtained from the orbiter in the landing configuration in the presence of the ground for structural strength analysis. This was accomplished by locating as many as 30 static pressure bugs at various locations on external model surfaces as each configuration was tested. A complete pressure loads survey was generated for each configuration by combining data from all bug locations, and these loads are described for the fuselage, wing, vertical tail, and landing gear doors. Aerodynamic force data was measured by a six component internal strain gage balance. This data was recorded to correct model angles of attack and sideslip for sting and balance deflections and to determine the aerodynamic effects of landing gear extension. All testing was conducted at a Mach number of 0.165 and a Reynolds number of 1.2 million per foot. Photographs of test configurations are shown.

Soard, T. L.↗
NASA NTRS1976

Single stage, low noise, advanced technology fan. Volume 1: Aerodynamic design

The aerodynamic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec 11,650 ft/sec). The fan and booster components are designed in a scale model flow size convenient for testing with existing facility and vehicle hardware. The design corrected flow per unit annulus area at the fan face is 215 kg/sec sq m (44.0 lb m/sec sq ft) with a hub-tip ratio of 0.38 at the leading edge of the fan rotor. This results in an inlet corrected airflow of 117.9 kg/sec (259.9 lb m/sec) for the selected rotor tip diameter if 90.37 cm (35.58 in.). The variable geometry inlet is designed utilizing a combination of high throat Mach number and acoustic treatment in the inlet diffuser for noise suppression (hybrid inlet). A variable fan exhaust nozzle was assumed in conjunction with the variable inlet throat area to limit the required area change of the inlet throat at approach and hence limit the overall diffusion and inlet length. The fan exit duct design was primarily influenced by acoustic requirements, including length of suppressor wall treatment; length, thickness and position on a duct splitter for additional suppressor treatment; and duct surface Mach numbers.

Sullivan, T. J.↗
NASA NTRS1976

Single stage, low noise, advanced technology fan. Volume 2: Structural design

The structural design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec). This mechanical design report describes the fan rotor design and the design of various structures of the vehicle; eg, stators, casings, splitters, seals, adapters, etc.

Schoener, J. L.↗
NASA NTRS1976

Single stage, low noise advanced technology fan. Volume 3: Acoustic design

The acoustic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec). The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise is accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels (20 EPNdB) below current Federal Air Regulation noise standards for a full-scale fan at the takeoff, cutback, and approach conditions. Predicted unsuppressed and suppressed fore and aft maximum perceived noise levels indicate that the cutback condition is the most critical with respect to the goal, which is probably unattainable for that condition. This is also true for aft radiated noise in the approach condition.

Kazin, S. B.↗
NASA NTRS1975

Two-stage, low noise advanced technology fan. Volume 2: Aerodynamic data

Aerodynamic data from static tests of a two-stage advanced technology fan designed to minimize noise are presented. Fan design conditions include delivery of 209.1kg/sec/sq m (42.85 lbm/sec/sq ft) specific corrected flow at an overall pressure ratio of 1.9 and an adiabatic efficiency of 85.3 percent. The 0.836m (2.74ft) diameter first stage rotor has a hub/tip ratio of 0.4 and 365.8m/sec (1200ft/sec) design tip speed. In addition to the moderate tip speed and pressure rise per stage, other noise control design features involve widely spaced blade rows and proper selection of blade-vane ratios. Aerodynamic data are presented for tests with unifrom and with hub and tip radially distorted inlet flow. Aerodynamic data are also presented for tests of this fan with acoustic treatments, including acoustically treated casing walls, a flowpath exit acoustic ring, and a translating centerbody sonic inlet device. A complete tabulation of the overall performance data, the blade element data, and the power spectral density information relating to turbulence levels generated by the sonic inlet obtained during these tests is included. For vol. 1, see N74-33789.

Harley, K. G.↗