Simulations helps scientists understand and control turbulence in humans and machines

Jul 01, 2014 by Aaron Dubrow
Air pushed through the vocal folds causes them to vibrate and create an unsteady jet that generates sound. The sound is modified as it travels through the throat, nose and tongue and, eventually, leaves the speaker's mouth. Credit: Daniel J. Bodony, Department of Aerospace Engineering, University of Illinois at Urbana-Champaign

Aerospace engineers from the University of Illinois, Urbana-Champaign are using the National Science Foundation-supported Stampede supercomputer to explore how jets in general, like those on modern aircraft and inside the human body, generate noise.

Jet engines generate intense sound waves that bother people who live near active airports. The noise can be so bothersome that limits are often placed on how loud aircraft can be and how many aircraft can fly over residential communities. Making aircraft quieter requires new engine designs; however, no simple explanation of how jets generate noise is available.

Daniel Bodony and his colleagues are trying to solve this problem. They are using Stampede to simulate the turbulent motion generated by air moving from the and then virtually testing the shape and location of actuators and acoustic liners that can reduce jet noise. This research has been published in the Journal of Fluid Mechanics and Physics of Fluids.

In related research, Bodony is seeking to understand how the voice is created, which also relies on the research around the aeroacoustics of jets. However, this time the unsteady jet of air is created by vocal folds, or vocal chords, when a person speaks.

Once speech production is understood, Bodony and his team will use Stampede to determine how to design synthetic to restore speech when it is lost due to strokes or other pathologies.

"Stampede has been a very easy platform on which to run our production simulations, and its more-than-two-times speed advantage over Ranger quickly made it a favorite," Bodony said. "It is our workhorse platform and enables our fundamental research that supports science and engineering objectives, including jet noise reduction, human voice prediction and control, and analysis of future high-speed aircraft systems."

Explore further: Seeking reality in the future of aeronautical simulation

More information: "Interaction of a Mach 2.25 turbulent boundary layer with a fluttering panel using direct numerical simulation." Christopher M. Ostoich, et al. Phys. Fluids 25, 110806 (2013); dx.doi.org/10.1063/1.4819350

"Adjoint-based control of loud events in a turbulent jet" is available online: jbfreund.mechse.illinois.edu/P… -freund-jfm-2014.pdf

add to favorites email to friend print save as pdf

Related Stories

UC discoveries could help quiet the world's cities

Aug 14, 2012

They’re sleek. They’re fast. They’re powerful. And, they are deafening. Furthermore, those Top Gun military jets need to be up in the air in the wee hours – over land – to simulate their landings ...

Jet engines help solve the mysteries of the voice

Mar 13, 2007

Although scientists know about basic voice production—the two "vocal folds" in the larynx vibrate and pulsate airflow from the lungs—the larynx is one of the body's least understood organs.

Recommended for you

What time is it in the universe?

Aug 29, 2014

Flavor Flav knows what time it is. At least he does for Flavor Flav. Even with all his moving and accelerating, with the planet, the solar system, getting on planes, taking elevators, and perhaps even some ...

Watching the structure of glass under pressure

Aug 28, 2014

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these ...

Inter-dependent networks stress test

Aug 28, 2014

Energy production systems are good examples of complex systems. Their infrastructure equipment requires ancillary sub-systems structured like a network—including water for cooling, transport to supply fuel, and ICT systems ...

Explainer: How does our sun shine?

Aug 28, 2014

What makes our sun shine has been a mystery for most of human history. Given our sun is a star and stars are suns, explaining the source of the sun's energy would help us understand why stars shine. ...

User comments : 0