Numerical Simulations Hoped to One Day Cut Expensive Flight Test Costs

  • Published
  • By William Sharp
  • AFOSR Public Affairs
An Arizona State University scientist, together with colleagues from Boeing Commercial Airplanes and Cobalt Solutions and funded by the Air Force Office of Scientific Research here, is working on computer simulations hoped to one day save precious defense dollars used for flight experiments and tests.

"In general, we call it computational simulations. It is a method that uses simulations to study many kinds of problems," said Dr. Kyle D. Squires, a mechanical and aerospace engineering professor at ASU.

"A number of scientists believe simulations will become the standard method of evaluating a system before it's ever built," said Squires. "In that respect, simulations have great potential in showing problems and flaws before a system is constructed. That's important because the savings could be substantial when you consider the costs associated with repair after a system has been fielded."

Building upon previous and related AFOSR-funded studies, Squires has been working on this project at ASU for about 4 years. Squires works with Drs. Philippe Spalart at Boeing and James Forysthe of Cobalt Solutions on simulations that involve highly-accurate mathematical computations. In this study, Squires hopes to eventually build or contribute to building a computer model capable of integrating and analyzing real-time information coupled with a variety of complex, military-relevant problems. The information could include weather conditions, aircraft capability and aerodynamics, and mission parameters. Based on the data entered, the computer model could accurately predict an outcome just as it would have occurred in real life. For that reason, simulations are very intriguing in a number of ways.

"For one thing simulations help us learn at a much more detailed level than, let's say, using wind tunnels or flight tests," said Squires. "We can learn, for example, air flow's affect on flight performance," something that can be hard for a wind tunnel or flight test to mimic.

"Second, simulations can be performed at the same conditions - weather, altitude, etc. - as experienced by an aircraft. In a wind tunnel, that's difficult to do," Squires said. "You can, of course, duplicate (real world) conditions in a flight test, but the level of detail tends to be more general." A third benefit of simulation is that it can expand ability to see depth in limitations or vulnerabilities in, for example, a weapons system - vulnerabilities that might only be detectable through simulations. That sort of information could be of great value to engineers, aircraft designers, and others.

"A flight test could involve a few select conditions while a simulation could conceivably examine everything else. I think that's a very cost effective way to do it. " Squires said.

Perhaps the greatest value of simulations is their ability to save resources and answer critical questions in the early stages of systems development. That's because simulations can help evaluate practicality and performance of a system before actually building or enhancing it, questions far less expensive to correct on the drawing table than after the system is built or in production.

To illustrate his work, Squires has a computer simulation of a jet aircraft spinning in flight. The aircraft simulation has similarities, visually speaking, to programs computer game makers are able to create. But that's where the similarities end, he said.

"The biggest difference is we calculate and accurately model the air flow around the aircraft," said Squires. "The jet aircraft in our simulation is spinning because of the movement of air flow around it. The computer game maker is not necessarily interested in what an aircraft is realistically capable of doing. He would, I imagine, be more focused on visual effect."

Air flow impact on air vehicles is of particular interest to the Air Force, but Squires' research has a number of potential applications. Theoretically, race cars, submarines, and potentially even sports industries could benefit from this particular study. In another project he's working with the golf industry to help build an aerodynamically-superior ball.

By supporting research workshops like this, AFOSR continues to expand the horizon of scientific knowledge through its leadership and management of the Air Force's basic research program. As a vital component of the Air Force Research Laboratory, AFOSR supports the Air Force's mission of control and maximum utilization of air and space. Many of the technological breakthroughs enjoyed by millions today, such as lasers, GPS, and the computer mouse trace their scientific roots to research first funded by AFOSR .