In general, chaos is rarely a good thing.

When it comes to air flow around aircraft, chaos is inevitable, especially when the aircraft is near stall conditions.

While researchers might not ever be able to correlate specific changes in design to equally specific and predictable changes in flow, being able to better characterize and understand ranges in which flow might occur would go a long way in improving flight performance and design.

That’s the goal of new research being undertaken by Department of Mechanical, Aerospace, and Biomedical Engineering (MABE) Assistant Professor James Coder.

“The problem is that airflow is dominated by chaotic behaviors, where even a minute change can quickly make a major difference,” said Coder. “Turbulent separated flows are an inevitable part of aerodynamics; we just need to develop the tools and mathematics to make sure they behave the way we want. We want to control the chaos.”

Achieving and maintaining flight requires overcoming several factors, including aspects of air flow. If an aircraft design creates a severe area of drag, for example, vehicle speed is negatively impacted.

While sensors can monitor real-world levels, designing better aircraft requires an understanding of the physics of airflow and flight at the theoretical level, which is where Coder’s work comes into play.

His plan is to use what is known as the adjoint process to work back from data points to see what actions lead to desired reactions. Chaos in the turbulence makes this challenging by obscuring the cause-and-effect relations.

“By running such computational simulations, we can amass a vast database of results that we can then use to start building some predictive modelling,” said Coder. “What we are doing, in a sense, is riding out the storm of chaos to learn how to design better aircraft.”

With the implications to their aircraft obvious, it should come as no surprise that the US Air Force (USAF) is supporting Coder’s work through their Young Investigator Research Program (YIP). His project is only the second USAF at UT, along with MABE Assistant Professor Damiano Baccarella, who earned the recognition in 2020.