I was excited to hear that the LEAP-X engine (Leading Edge Aviation Propulsion) developed by CFM International, a 50/50 joint venture between GE and Snecma (SAFRAN group), was chosen to power 100% of the Boeing airplanes purchased today by American Airlines. The research groups I lead in the Thermal Systems Organization at Global Research have been developing a range of technologies that are important for that engine, and we can’t wait to see them in action. We have dedicated teams focused on developing new ways of cooling the engine, which is critical for performance. Jet engines burn fuel much hotter than the melting point of the materials in the engine – the hotter the better. Burning hotter leads to better fuel efficiency. To compensate, we cool those parts very aggressively. The turbine uses a ton of cooling air to make the engine durable, but that cooling air HURTS fuel efficiency. The life of a turbine heat transfer researcher is to get more and more cooling, with less and less air, and do so in such a way that we have excellent confidence in the durability of our engines.
We work directly with the Aviation engine designers in several ways, especially on the LeapX engine. One thing we do is develop new cooling features for the components in the engine. In turbine cooling, that often means new internal heat transfer augmentation technologies, among other things. My team does a lot of experimental testing of these new features to provide the evidence we need to deploy them in the engines optimally.
We also develop new ways of modeling turbines. CFD – computational fluid dynamics – is a ubiquitous capability in our design process. It’s easy to do a detailed simulation of a jet engine and get an answer that LOOKS good, but it takes an expert to get an answer that is RIGHT. Ourteam spends a lot of time developing new modeling and simulation methodologies that are being used daily to simulate many regions in of the LeapX.
At some point we need to know if we got the design right, and that requires exotic measurement technologies. Our team is constantly developing new measurement technologies that allow us to probe in an engine to get accurate measurements of performance, particularly with ever-increasing spatial density. With the complexity of making these measurements in the hot, harsh environment on the inside of a jet engine, we need researchers who devote their careers to getting expert in relevant measurement technologies.
All of these technologies are hard, they require lots of resources and very bright scientists, but they are required to make an engine as sophisticated and as fuel efficient as the LEAP-X. Stay tuned as we get closer to the flight test date for this engine.