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Wright, R. E., Jr.

Publications and source records attributed to Wright, R. E., Jr..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Comparisons of boundary-layer transition measurement techniques in the Langley Unitary Plan wind tunnel

Four different boundary-layer transition detection techniques, namely liquid crystals, very thin hot films, IR photography, and an optical interferometer, were compared using the same flat plate model for the same tunnel conditions. The comparisons, conducted at NASA-Langley, involved not only their sensitivity to transition but also their ease of use. The thin films, as expected, gave excellent quantitative information and were used as the standard for evaluating the other techniques. Both the liquid crystals and IR photography were able to detect transition before the boundary-layer intermittency factor had reached 50 percent. The optical interferometer was unsuccessful. Conditions sampled included a range of Mach numbers from 1.5 to 2.5 and unit Reynolds numbers from 1.0 to 4.0 million/foot.

Hall, R. M.↗
NASA NTRS1988

In-flight flow visualization using infrared imaging

A flight test investigation was conducted to evaluate infrared (IR) flow imaging techniques for boundary-layer flow visualization. The flight tests used a single-engine turboprop aircraft with a fiberglass-skinned natural laminar flow glove mounted on the left wing and an infrared imaging system to obtain flow visualization data. Data were compared to results obtained from other more conventional boundary-layer flow visualization methods and found to agree well. Test flights were conducted to determine the effect of test surface color on IR flow visualization results. In addition, flights were made during both night and daylight hours to assess the effect of solar radiation on the results. The investigation included an effort to visualize a vortex passing over the wing glove, but the tests provided only limited results.

Brandon, J. M.↗
NASA NTRS1986

Radiometric responsivity determination for Feature Identification and Location Experiment (FILE) flown on space shuttle mission

A procedure was developed to obtain the radiometric (radiance) responsivity of the Feature Identification and Local Experiment (FILE) instrument in preparation for its flight on Space Shuttle Mission 41-G (November 1984). This instrument was designed to obtain Earth feature radiance data in spectral bands centered at 0.65 and 0.85 microns, along with corroborative color and color-infrared photographs, and to collect data to evaluate a technique for in-orbit autonomous classification of the Earth's primary features. The calibration process incorporated both solar radiance measurements and radiative transfer model predictions in estimating expected radiance inputs to the FILE on the Shuttle. The measured data are compared with the model predictions, and the differences observed are discussed. Application of the calibration procedure to the FILE over an 18-month period indicated a constant responsivity characteristic. This report documents the calibration procedure and the associated radiometric measurements and predictions that were part of the instrument preparation for flight.

Wilson, R. G.↗
NASA NTRS1973

Evaluation of radioisotope tracer and activation analysis techniques for contamination monitoring in space environment simulation chambers

Radioisotope measurement techniques and neutron activation analysis are evaluated for use in identifying and locating contamination sources in space environment simulation chambers. The alpha range method allows the determination of total contaminant concentration in vapor state and condensate state. A Cf-252 neutron activation analysis system for detecting oils and greases tagged with stable elements is described. While neutron activation analysis of tagged contaminants offers specificity, an on-site system is extremely costly to implement and provides only marginal detection sensitivity under even the most favorable conditions.

Smathers, J. B.↗