Garbeff, Ted | Search NASA

NASA NTRS2019

NASA Ames Unitary Plan Wind Tunnel: Infrared Flow Visualization

Infra-red thermography can visualize surface flow features including boundary layer transition, shock impingement, streamwise vortex impingement, flow separation, and buffet. The Infra-red thermography system at the NASA ARC Unitary Plan Wind Tunnel allows for continuous monitoring of wind tunnel models with up to four cameras simultaneously. For best results the models should be covered with a high emissivity coating, and the images processed to enhance contrast. However image processing algorithms allow some flow information to be recovered even from uncoated models.

Garbeff, Ted↗

NASA NTRS2015

Institutional Schlieren: A Production-Level Wind Tunnel Test Measurement

The following details recent efforts undertaken at the NASA Ames Unitary Plan Wind Tunnel to design and deploy an advanced, institutional, production-level data system for the classical Schlieren-shadowgraph technique. Motivation for the selection of individual system components is discussed along with a software methodology that combines image acquisition and processing into a production-level wind tunnel test measurement. In general terms, a production-level measurement refers to any data system that is seamlessly integrated into the primary wind tunnel data system, and whose data products are available real-time (e.g. force and moment, pressure, temperature data). The advantage of integrating a measurement in such a manner is an immediate increase in data product efficiency, productivity, reliability, and quality. Coupled with these benefits and leveraging recent advancements in high-speed imaging and image processing, automated, synchronized, time-resolved Schlieren-shadowgraph imaging for dynamic flow phenomena is now a reality. This makes possible the synthesis of dynamic off-body imaging with unsteady on-body measurements to produce a uniquely descriptive data product invaluable to the modern researcher.

Shadowgraph↗