Engineering Papers⌕ Search

Engineering topics

Nealy, J. E.

Publications and source records attributed to Nealy, J. E..

45 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Estimates of nonequilibrium radiation for Venus entry

The present investigation is an analysis of the radiation from the chemical nonequilibrium region in the shock layer about a vehicle during Venus entry. The radiation and the flow were assumed to be uncoupled. An inviscid, nonequilibrium flowfield was calculated and an effective electronic temperature was determined for the predominant radiating species. Species concentrations and electronic temperature were then input into a radiation transport code to calculate heating rates. The present results confirm earlier investigations which indicate that the radiation should be calculated using electronic temperatures for the radiating species. These temperatures are not related in a simple way to the local translational temperature. For the described mission, the nonequilibrium radiative heating rate is approximately twice the corresponding equilibrium value at peak heating.

Grose, W. L.↗
NASA NTRS1974

Recommended radiative property data for Venusian entry calculations

A compilation of experimental and calculated data on the radiative properties species important in Venusian entry is presented. Molecular band systems, atomic lines, free-bound, and free-free continua are considered for the principal radiating species of shock heated carbon dioxide. A limited amount of data pertinent to the species in the ablation layer is also included. The assumption is made that the Venus atmosphere so closely approximates pure CO2 that the inviscid layer radiation is due almost entirely to thermally excited CO2. The only exception is the inclusion of data on the Violet band system of CN. Recommendations are made as to best property values for radiative heating calculations. A review of the basic equations and the relationships of the various emission-absorption gas porperties is also included.

Jones, J. J.↗
NASA NTRS1974

Radiative property data for Venusian entry: A compendium

A compilation of experimental and calculated data on the radiative properties of species important in Venusian entry is presented. Molecular band systems, atomic lines, free-bound continua, and free-free continua are considered for the principal radiating species of shock-heated carbon dioxide. Data pertinent to the species in the ablation layer are included. The Venus atmosphere so closely approximates pure carbon dioxide (CO2) that the inviscid layer radiation is due almost entirely to thermally excited CO2. Data are included on the violet band system of the cyanogen radical CN. Recommendations are made as to best property values for radiative heating calculations. A review of the basic equations and the relationships of the various emission-absorption gas properties is included.

Jones, J. J.↗
NASA NTRS1973

Combustion detector

A device has been developed for generating a rapid response signal upon the radiation-emitting combustion reaction of certain gases in order to provide a means for the detection and identification of such reaction and concurrently discriminate against spurious signals. This combustion might be the first stage of a coal mine explosion process, and thereby this device could provide a warning of the impending explosion in time to initiate quenching action. This device has the capability of distinguishing between the light emitted from a combustion reaction and the light emitted by miners' lamps, electric lamps, welding sparks or other spurious events so that the quenching mechanism is triggered only when an explosion-initiating combustion occurs.

Trimpi, R. L.↗
NASA NTRS1973

A shock-tube study of radiation behind shock waves in CO2 with application to Venus entry

The arc-driven Langley 6-inch shock tube has been used to produce shock waves in CO2 in the speed range between 9 and 13 km/sec at ambient pressures between 0.1 and 5 torr. These pressures correspond approximately to equivalent Venus altitudes between 100 and 80 km. Radiation intensity profiles behind the shock waves have been observed for several wavelengths at which the important species emit. Observation and analysis of the luminosity profiles in the zone of chemical nonequilibrium have been given particular emphasis. The results of the measurements are employed in the prediction of nonequilibrium radiative heating to a typical blunt-body probe entering the Venus atmosphere on a ballistic trajectory.

Nealy, J. E.↗
NASA NTRS1972

Performance and operating characteristics of the arc-driven Langley 6-inch shock tube

Performance characteristics for the arc-driven Langley 6-inch shock tube were determined for driver energies from 0.62 to 5 MJ. Voltage, current and pressure histories of the arc driver were recorded, and driver efficiencies were determined from measured shock velocities. Time-resolved spectra for test gases of air, carbon monoxide, xenon, and a mixture of 80 percent helium and 20 percent hydrogen are presented.

Nealy, J. E.↗