Schlieren System Captures Brilliant Shockwave Images

Supersonic flight over land is generally prohibited because sonic booms created by shockwaves disturb people on the ground and can damage property. Armstrong innovators are working to solve this problem through a variety of innovative techniques that measure, characterize, and mitigate sonic booms. The BOSCO technology is helping researchers understand how sonic booms travel through the air. How It Works Armstrong's patented system visualizes air density gradients generated by air compressing as it flows around an object. Researchers first obtain a celestial background image and then collect a series of images of an object in supersonic flow in front of the celestial object. The density change in the air refracts the light, shifting the background as compared to the undisturbed background image. The amount of movement corresponds directly to density gradients in the airflow. Using computer algorithms to analyze the images, resultant images essentially show the distortions caused by the aerodynamic flow of shockwaves passing between the camera and the celestial background. Why It Is Better Schlieren photography has been used for years in wind tunnels, where the environment is controlled. BOSCO enables its use in the real atmosphere with real propulsion systems. Studying life-sized aircraft flying through Earth's atmosphere provides better results than modeling and can help engineers design better and quieter supersonic airplanes. In addition to studying shock waves for aircraft, NASA's schlieren techniques have the potential to aid the understanding of a variety of flow phenomena and air density changes, such as investigating air flows around tall buildings and the tips of wind turbines and helicopter blades.