In a series of experimental tests called the Matt Menke Indianapolis GE Engineer Project, engineers investigated the breakdown locations of certain types of airflow currents across the edges of delta wing structures. Flow visualization techniques allowed engineers to locate the wing’s response to the smallest oscillations in these currents. Menke and his team found that the port and starboard currents are in-phase with one another as well as the pitching frequency when a plane starts to climb at a moderate angle of attack.
Low-frequency asymmetric data reared its ugly head when simulated delta wing planes climbed at sharp attack angles. This data was very similar to data collected at the same time from the symmetric mode at the pitching frequency. Engineers previously weren’t sure whether or not there were multiple frequencies on a single wing like this. The existence of these features in the spectra suggests that air vortices that break apart over the delta wing structure tend to behave like a self-excited oscillator operating as something other than a line.
It’s not easy to graph this data, which ultimately makes it difficult to visualize it. Menke came up with some unique techniques to do so when he led the team that worked on these projects. He drew on nearly 20 years of engineering experience when developing these new methods. Menke previously provided support for both innovative and legacy technology in the aviation sector. This gave him a few unique skills that helped him solve the problem of how to visualize this data.
Menke once worked in the field of naval acoustics, and he provided technical leadership as well as program management for various acoustic data analysis projects before working on these delta wing experiments. Acoustic data is inherently non-visual, which makes interpretation of it obtuse for the uninitiated. Technicians can map individual sound waves to mathematical values.
Each mechanical wave resonates at a specific frequency, which a technician can express in terms of cycles per second. The technician can then record this number as a certain hertz value. One hertz equals one wave cycle in a second. This means when a nautical engineer observes a clean sonar ping vibrating at 600 cycles per second they can unquestionably say that the ping exhibits a 600 Hz sound wave.
Nautical technicians can also take note of the duration of the tones as well as any time intervals where tones ceased transmitting. Each of these values can map to points on a scatter plot. This provides engineering teams a way to visualize data that it would have otherwise been impossible for them to see. Menke took note of these techniques when he tackled the issue of analyzing low-frequency asymmetric data related to vortices surrounding delta wing aircraft.
While it might not be possible to measure an air current directly, it’s certainly possible to measure how fast each vortex breaks down. When Menke combined this data with all of the raw frequency numbers he took in the first part of the study, he found that it’s possible to make visual scatter plots of this data that helps engineering teams better understand what’s going on when a delta wing aircraft pulls up at a sharp angle of attack. By using a wave tank to simulate the flow of air over a metal wing, Menke was also able to snap a large number of detailed photographs that showed precisely where these vortices break apart.
Even though he’s a mechanical engineer, Menke didn’t just apply his technical acumen to this project. Presenting highly technical issues to executives, external customers and business associates can be challenging. Business and engineering personnel have a profound respect for one another, but their backgrounds are very different. This also means that they often have very different concerns when it comes to working with a project.
Menke worked with Earned Value Management (EVM) techniques on a variety of projects before this series of experiments. He knew how to plan research to focus on major goals that would bring about an economic benefit for those who were backing it. That helped to reduce the kinds of hiccups that engineers often have to deal with when working with the business side of the equation.
General Electric put the findings of his research into play as soon as he completed it. Other technical personnel at GE took the findings from these studies and applied it to their aviation department to help them make new types of components for delta wing aircraft. These devices in turn are very beneficial to the defense sector, which needs them for flying simulated combat missions. Few pilots are currently qualified to fly this sort of aircraft, so any improvements to the equipment will also help those learning to fly them. Pitching and rocking motions caused by these vortices makes it relatively difficult to fly delta wing aircraft. Reducing these motions can make them much more accessible to a wider variety of military pilots.
Future engineers might be able to design even better components that could give pilots more control over delta wing aircraft. While crews have long viewed delta wing designs as superior to conventional aircraft, their difficult handling characteristics have hurt them as far as adoption is concerned. New control mechanisms based on Menke’s research might very well usher in a new generation of delta wing combat aircraft. Both the USAF and USN would be extremely interested in this type of technology.