Airborne Background Oriented Schlieren Technique

About this technology

Overview

NASA has developed a novel method to render visible the density changes in air that cause a refractive index change by an airborne vehicle. These density changes include shock waves, vortices, engine exhaust, and wakes. The determination of location and strength of shockwaves and vortices is fundamental to understanding the flow around an aircraft. These features are strong enough to affect the environment that the vehicle inhabits: for example, they can cause drag and/or produce undesirable noise. The researcher must be able to predict and mitigate the effects of these flow features. This invention is a robust visualization technique that will permit the measurement of the strengths and positions of shock waves caused by supersonic vehicles. The technique is applicable to all flight regimes, however, and can be used for visualizing tip vortices, engine exhaust plumes.