Particle physics research

DVIDS – News – NPS Research seeks to advance aircraft turbine resiliency to particulate matter

In late 2015, two Marines were killed and 20 others injured after an MV-22 Osprey crashed during pre-deployment training at Bellows Air Force Base in Hawaii. The culprit… Airborne sand and dust particles caused brownout conditions for airmen and were ingested into the aircraft’s engines, melting due to high temperatures and degrading internal components compromising the aircraft’s power and lift.

Less than a month later, when the Momotombo volcano erupted, commercial flights were forced to stay on the ground to avoid ingesting particles from the volcano’s lingering explosion.

Sand, dust and other particles have been a thorn in the side of aviation technology for decades. In the 90s, the problem was mainly centered on erosion, but better coatings on the engines solved this problem.

Now the problem is more related to the high temperatures generated in the new turbine engines, which allows for increased performance and power. To their detriment, however, these higher temperatures melt the particles as they are ingested into the engine, which can clog the turbine.

Naval Postgraduate School (NPS) physics student and Meyer Scholar, Lt. Erick Samayoa and his advisor, Dr. Andy Nieto, NPS Assistant Professor of Mechanical and Aerospace Engineering (MAE) – with the help of fellow Assistant Professor of research NPS MAE Troy Ansell and UC San Diego NanoEngineering Professor Jian Luo – discovered that ultra-high temperature ceramics (UHTC) could be sand phobic… In other words, molten sand does not stick to them.

Their study, funded by the Strategic Engineering and Research Development Program (SERDP), was the first to examine the potential for use of UHTCs in aircraft turbines. SERDP is a joint effort of the Department of Defense (DoD), the Environmental Protection Agency (EPA), and the Department of Energy (DoE). This project was part of a collaboration between the NPS, the US Army Laboratory, Stony Brook University and materials company Oerlikon Metco.

While various companies have developed filters to reduce the input of sand, it is almost impossible to keep every particle out of a turbine, and unfortunately the smallest particles melt the easiest. Other research has looked for ways to slow the melting of sand and other particles by rapidly resolidifying them through the introduction of feedback, but this has not stopped the particles from sticking to the engine first. location.

So the NPS team decided to look at the problem from a materials perspective. Before coming to the NPS about four years ago, Nieto worked at the U.S. Army Research Laboratory (ARL) and brought his research and ARL partnership with him to the NPS.

Ansell brought the team images of different particles exposed to ultra-high temperatures captured with a transmission electron microscope to see if and how they interacted with UHTCs. Luo provided the ceramic materials and helped analyze the results using his expertise in high-entropy ceramics.

Samayoa says the whole project was a steep learning curve since he was a physics student, but the research was a good fit with his goals. And the quality of his work has been demonstrated, said Nieto, saying that the research carried out by Samayoa would be work worthy of a doctoral student.
The challenge of simulating the heat emitted by modern gas turbines adds to the complexity of research using UHTC. Researchers had to find a way to test materials at this temperature, forcing the team to acquire the hottest oven NPS had ever had. Once operational, the research team developed a project to test UHTCs at different temperatures for different durations.

“We were even the first to experiment at these higher temperatures for any material for these applications,” Nieto says. “It was quite unexpected that as you go up in temperature, you actually get some degree of chemical inertness from these ultra-high temperature ceramics where they don’t interact with the molten sand. This opens up a possible path in how we design these engines.”

The researchers published their findings in the materials science journal, Materialia, in December 2021. Samayoa, a surface warfare officer, has now graduated and is currently completing the Department Head pipeline before running as as a weapons officer aboard the USS Princeton.







Date taken: 25.03.2022
Date posted: 25.03.2022 11:57
Story ID: 417173
Location: MONTEREY, CA, USA





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