Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “LINER”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Double-peaked broad line emission from the LINER nucleus of NGC 1097

We report the recent appearance of a very broad component in the H-alpha and H-beta emission lines of the weakly active nucleus of the Sersic-Pastoriza galaxy NGC 1097. The FWZI of the broad component is about 21,000 km/s, and its profile is double-peaked; the presence of a blue, featureless continuum in the nucleus is also suggested. The broad component was first observed in H-alpha in November 2, 1991, and confirmed 11 months later. The H-alpha profile and flux did not change in this time interval. Comparison with previously published spectral data indicates that the broad lines have only recently appeared. Together with the relatively high X-ray luminosity and the compact nuclear radio source, our results characterize the presence of a Seyfert 1 nucleus in a galaxy which had previously shown only LINER characteristics. Obscuring material along our line of sight to the nucleus appears to have recently cleared, permitting a direct view of the active nucleus. We discuss two possible structures for the broad line region, biconical outflow and an accretion disk, that could give rise to the observed profile.

Storchi-Bergmann, Thaisa↗
NASA NTRS1958

Discharge Coefficients for Combustor-liner Air-entry Holes II : Flush Rectangular Holes, Step Louvers, and Scoops

Experimental discharge coefficients for various types of combustor-liner air-entry holes are presented as a function of a dimensionless flow parameter. In general, scoops and step louvers have higher discharge coefficients and wider flow ranges than flush holes. The effects of size or shape of a given type of hole are small. The proximity of multiple flush holes or the wall inclination of a convergent duct has a negligible effect on discharge coefficient.

FLOW, COMPRESSIBLE↗
NASA NTRS1994

Target compressions by working fluids driven with solid liner implosions

Compression by a spherical solid liner of a gold target surrounded by a hydrogen plasma is simulated. Two-dimensional simulations that treat only a subset of the physics included in the one-dimensional code were performed in an attempt to assess multidimensional effects. A one-dimensional numerical code has been developed to study the effects of thermal radiation and conduction. Results of pressure, density, and energy deposited for different initial plasma conditions are presented and discussed. Results from both one- and two-dimensional codes show that the average target density at peak compression is 39-43 g/cu cm, using the SHIVA Star facility at 90 kV discharge.

Chiang, P.-R.↗
NASA NTRS2000

GRCop-84 Development for Combustion Chamber Liners

The development, test, and thermophysical & mechanical properties of a GRCop-84 alloy for combustion chamber liners is discussed. Topics discussed include: History of GRCop-84 development, GRCop-84 thermal expansion, thermal conductivity of GRCop-84, yield strength of GRCop-84, GRCop-84 creep lives, GrCop-84 low cycle fatigue (LCF) lives, and hot fire testing of GRCop-84 spool pieces.

Ellis, David↗
NASA NTRS2003

Vacuum Plasma Spray Forming of Copper Alloy Liners for Regeneratively Cooled Liquid Rocket Combustion Chambers

Vacuum plasma spray (VPS) has been demonstrated as a method to form combustion chambers from copper alloys NARloy-Z and GRCop-84. Vacuum plasma spray forming is of particular interest in the forming of CuCrNb alloys such as GRCop-84, developed by NASA s Glenn Research Center, because the alloy cannot be formed using conventional casting and forging methods. This limitation is related to the levels of chromium and niobium in the alloy, which exceed the solubility limit in copper. Until recently, the only forming process that maintained the required microstructure of CrNb intermetallics was powder metallurgy formation of a billet from powder stock, followed by extrusion. This severely limits its usefulness in structural applications, particularly the complex shapes required for combustion chamber liners. This paper discusses the techniques used to form combustion chambers from CuCrNb and NARloy-Z, which will be used in regeneratively cooled liquid rocket combustion chambers.

Zimmerman, Frank↗
NASA NTRS1996

Validation of a Numerical Method for Determining Liner Impedance

This paper reports the initial results of a test series to evaluate a method for determining the normal incidence impedance of a locally reacting acoustically absorbing liner, located on the lower wall of a duct in a grazing incidence, multi-modal, non-progressive acoustic wave environment without flow. This initial evaluation is accomplished by testing the methods' ability to converge to the known normal incidence impedance of a solid steel plate, and to the normal incidence impedance of an absorbing test specimen whose impedance was measured in a conventional normal incidence tube. The method is shown to converge to the normal incident impedance values and thus to be an adequate tool for determining the impedance of specimens in a grazing incidence, multi-modal, nonprogressive acoustic wave environment for a broad range of source frequencies.

Watson, Willie R.↗
NASA NTRS1950

Ditching Investigation of a 1/15-Scale Model of the Convair-Liner Airplane

A ditching investigation of a model of the Convair-Liner airplane was made to observe the behavior and determine the safest procedure for making an emergency water landing. The ditching model was designed and constructed by the National Advisory Committee for Aeronautics. Design information on the airplane was furnished by the Consolidated Vultee Aircraft Corporation. A three-view drawing of the airplane is shown. The investigation was made in calm water at the Langley tank no. 2 monorail.

Fisher, Lloyd J.↗
NASA NTRS2010

Evaluating the Acoustic Effect of Over-the-Rotor Foam-Metal Liner Installed on a Low Speed Fan Using Virtual Rotating Microphone Imaging

An in-duct beamforming technique for imaging rotating broadband fan sources has been used to evaluate the acoustic characteristics of a Foam-Metal Liner installed over-the-rotor of a low-speed fan. The NASA Glenn Research Center s Advanced Noise Control Fan was used as a test bed. A duct wall-mounted phased array consisting of several rings of microphones was employed. The data are mathematically resampled in the fan rotating reference frame and subsequently used in a conventional beamforming technique. The steering vectors for the beamforming technique are derived from annular duct modes, so that effects of reflections from the duct walls are reduced.

Sutliff, Daniel L.↗
NASA NTRS2017

External Acoustic Liners for Multi-Functional Aircraft Noise Reduction

Acoustic liners for aircraft noise reduction include one or more chambers that are configured to provide a pressure-release surface such that the engine noise generation process is inhibited and/or absorb sound by converting the sound into heat energy. The size and shape of the chambers can be selected to inhibit the noise generation process and/or absorb sound at selected frequencies.

Jones, Michael G.↗
DOE OSTI2015

Recent Progress and Future Potential of Magnetized Liner Inertial Fusion (MagLIF)

The standard approaches to inertial confinement fusion (ICF) rely on implosion velocities greater than 300 km/s and spherical convergence to achieve the high fuel temperatures (T > 4 keV) and areal densities (ρr > 0.3 g/cm2) required for ignition1. Such high velocities are achieved by heating the outside surface of a spherical capsuleeither directly with a large number of laser beams (Direct Drive) or with x-rays generated within a hohlraum (Indirect Drive). A much more energetically efficient approach is to use the magnetic pressure generated by a pulsed power machine to directly drive an implosion. In this approach 5-10% of the stored energy can be converted to the implosion of a metal tube generally referred to as a “liner”. However, the implosion velocity is not very high 70-100 km/s and the convergence is cylindrical (rather than spherical) making it more difficult to achieve the high temperatures and areal densities needed for ignition.

Slutz, Stephen A.↗
DOE OSTI2019

Improved Performance of Polyurethane Foam Insulation Using Ingeo Biopolymer Liners and its Impact on Energy Efficiency of Refrigerator and Freezers

This paper compares the effect of isothermal aging of the thermal conductivity of polyurethane foam in simulated refrigerator-freezer panels made from polylactic acid biopolymer from NatureWorks (IngeoTM) and high-impact polystyrene. Specimens were aged at room temperature and thermal conductivity measurements were made at 10°C over a period of 2.4 years. The energy use over the life of refrigerator-freezer is also calculated using the Energy-Efficient Refrigerator Analysis program which was developed by the United States Department of Energy to estimate the energy savings potential of various technology option upgrades (cabinet and refrigeration system) for rulemaking purposes. The results show that energy savings from implementing the Ingeo liner range from 818 to 1395 kWh (7 to 13% of total energy use) over a 15-year period.

Hossieny, Nemat↗
DOE OSTI2024

High-modulus, high-strength, low alloy gray cast iron for cylinder liners and automotive applications

A high elastic modulus, high ultimate tensile strength, and low alloy gray cast iron for cylinder liners. The gray cast iron includes from 2.60 wt % to 3.30 wt % Carbon (C); from 1.50 wt % to 2.30 wt % Silicon (Si); from 0.30 wt % to 0.80 wt % Manganese (Mn); from 0.15 wt % to 0.35 wt % Phosphorus (P); from 0.05 wt % to 0.11 wt % Sulphur (S); from 0.60 wt % to 1.20 wt % Copper (Cu); from 0.10 wt % to 0.30 wt % Chromium (Cr); from greater than 0.0 wt % to 0.1 wt % Nickle (Ni); from 0.15 wt % to 0.40 wt % Molybdenum (Mo); and balance wt % Iron (Fe). The total wt % of Si, Mn, P, S, Cu, Cr, Ni, and Mo is less than about 4.10 wt %. The gray cast iron has a Carbon Equivalent (CE) from 3.00 wt % to 3.90 wt % and the product of Mn %*S % is from 0.025 to 0.045.

Yang, Jianghuai↗
NASA NTRSDate not supplied

Liner Physics Team Overview

Explore the source record for details and available documents.

LaRC Acoustics Liner Physics Team↗
DOE OSTI2014

Possible energy gain for a plasma-liner-driven magneto-inertial fusion concept

A one-dimensional parameter study of a Magneto-Inertial Fusion (MIF) concept indicates that significant gain may be achievable. This concept uses a dynamically formed plasma shell with inwardly directed momentum to drive a magnetized fuel to ignition, which in turn partially burns an intermediate layer of unmagnetized fuel. The concept is referred to as Plasma Jet MIF or PJMIF. The results of an adaptive mesh refinement Eulerian code (Crestone) are compared to those of a Lagrangian code (LASNEX). These are the first published results using the Crestone and LASNEX codes on the PJMIF concept.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗