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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 181 records · Page 10

Vector Radiative Transfer Code SORD: Performance Analysis and Quick Start Guide

We present a new open source polarized radiative transfer code SORD written in Fortran 9095. SORD numerically simulates propagation of monochromatic solar radiation in a plane-parallel atmosphere over a reflecting surface using the method of successive orders of scattering (hence the name). Thermal emission is ignored. We did not improve the method in any way, but report the accuracy and runtime in 52 benchmark scenarios. This paper also serves as a quick start users guide for the code available from ftp:maiac.gsfc.nasa.govpubskorkin, from the JQSRT website, or from the corresponding (first) author.

polarized radiative transfer↗

Investigation of Altitude Starting and Acceleration Characteristics of J47 Turbojet Engine

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.

IGNITION SYSTEMS↗

Preliminary results of turbojet-engine altitude-starting investigation

A spark energy of 2.13 joules per spark at 1 spark per second produced ignition to an altitude of 50,000 feet at a flight Mach number of 0.6. The minimum power requirements for ignition were obtained from a combination of low spark repetition rates and high spark energy. The altitude-ignition limit was also increased by increasing spark-gap immersion, fuel temperature, inlet-air temperature, and fuel volatility, and by decreasing flight Mach number. The maximum altitude at which flame propagation was accomplished from combusters with spark plugs to combusters without spark plugs to combustors without spark plugs was increased about 5000 feet by increasing fuel volatility.

COMBUSTION - IGNITION OF GASES↗

GRC MILab Software: Quick Start Guide

This document provides detailed installation and operating instructions for the GRC MILab Excel Add-In software developed at the NASA Glenn Research Center. The software described has been implemented to facilitate the process of importing into Microsoft Excel and analyzing materials test data from a wide range of materials tests. All resulting data is then ready for automated upload to the relevant table of the GRC Materials Intelligence (MI) database. This new software represents an update to the original MILab software developed by Granta Design Ltd.—a company specializing in materials software, data, and databases—for members of the Materials Data Management Consortium (MDMC), a collaboration between Granta, ASM International, NASA Glenn, and several other materials-oriented corporations and government agencies in the aerospace and defense industries. The updated software consists of the addition of two test type modules, the Generic and Generic Cyclic modules, with both representing a generalization of the original software. The Generic module supports the import and analysis of multiaxial data from any sequence of tensile, compression, relaxation, and/or creep test stages; and the Generic Cyclic module expands the functionality to include repeated sequences during cyclic testing. During processing, all imported data and analysis results are formatted by the software so as to be ready for immediate automated upload to the MI database, ensuring minimal overhead on the part of the user and access to persistent and reliable data for all relevant personnel.

Quick Start Guide↗

Temperature-stabilized, triggerable microelectronic astable multivibrator starts reliably

Multiple chip custom block, MIC construction is used to fabricate an ultracompact, low-power astable multivibrator. The design provides a multivibrator that free runs, eliminating lockup, is triggerable, pulling into synchronization with an external signal source, and permits design flexibility for controlling the frequency variations with temperature.

Stebbins, W. J.↗