Researchers at the Armstrong Flight Research Center of the National Aeronautics and Space Administration (NASA) have released stunning photos of a T-38C jet plane breaking the sound barrier and exhibiting images of shock waves that appeared as bended lines on the sides of the aircraft.
The magnificent photos were captured using a ground equipment that has a special optical filter that is directed upwards. Because of the said filter, the camera was able to produce a bright and granulated backdrop.
Having a bright light or a speckled backdrop such as the moon or sun is essential for viewing aerodynamic outflow produced by passing materials like an aircraft between the camera and the background. This method is called Background-Oriented Schlieren using Celestial Objects (BOSCO).
One of the most basic components of aeronautics studies is flow visualization. Schlieren photography, which is a method used to capture images of fluids with varying densities, have been used for years now. In the past, this process required a bright light and complicated and intricately-aligned optics. With this, capturing aircrafts while in flight was specifically hard because the sun and camera needed to be in perfect alignment.
Now, through the use of ground-based schlieren technology, experts were able to come up with adequate results using the edge of the sun as the bright light source. Edward Haering, an Armstrong engineer and the inventor of the BOSCO idea, was able to observe that the shockwaves also deformed any discernible sunspots.
"Using this naturally speckled background, we could make hundreds of observations of each shockwave, greatly increasing the acuity of the camera system," said Haering.
The experts found the new ground-based procedure as more cost-effective compared to air methods. By just removing the need for air-based camera, operational expenses were reduced, as well as the overall complicated features of the procedure.
Michael Hill, Armstrong principal investigator said that their team would also want to try the BOSCO system on other materials besides aircrafts. According to him, they could possibly conduct the schlieren imagery on anything that could align between the sun and their camera.
In future researches, flow fields of subsonic planes and wind turbine-generated aircrafts may be captured using an advanced system to photograph images of much higher resolution.
