Since a very young age, Sina Bahram, a Ph.D. student at North Carolina State University in Raleigh, has been blind.
“I did have a little bit more usable vision as a kid than I do now,” said Bahram.
But being blind hasn’t slowed him down. He’s a Ph.D. student and president of a consulting company. He has learned to feel his way through life. But there’s still one thing that’s a challenge to navigate: traffic.
A singer brings the wine glass to his lips. Unleashing a sustained note directly into the side of the glass, the goblet’s walls begin shaking. If the tone is just right, it can trigger vibrations in the brittle material that eventually causes the glass to shatter.
The phenomenon is called resonance, when a transmitted sound wave’s frequency matches the natural frequency of a receiving material and causes it to oscillate.
Now picture a rocket lighting up. It turns out that the same acoustic phenomenon can happen inside the liquid-fueled engine as combustion occurs. The results, as one might imagine, are not good.
“The flame is the singer that can excite a tone, and combustion can couple with the acoustics of the rocket chamber,” says John Bennewitz, a University of Alabama in Huntsville (UAH) graduate student and Von Braun Propulsion Fellow. “The tone can eventually rip the whole engine apart.”