Hi, my name is Jon Slepski and I manage the Turbine Thermal Physics and Measurements Lab at GE Global Research in Niskayuna, NY. The primary focus of my lab is to develop technologies for the accurate prediction and measurement of temperature in gas turbines and jet engines. This includes the temperatures of metal and ceramic components, as well as the temperature of the hot gases surrounding them.
Did you realize that over 20% of the air moving through the compressor section of a gas turbine is used to cool the turbine vanes and blades? The temperature of our combustion products is so high that if we didn’t actively cool these components, they would melt.
The next time you fly, think about it. The melting point of even the most advanced metals isn’t much higher than 2200F, but the combustion temperature is over 3000F! To improve our cycle efficiency and life of our turbines, my team at Global Research is constantly looking to improve our design tools through more accurate measurement techniques.
One way we stay current in our technical fields is through participation at conferences. This September, two researchers from my team, Mohamed Sakami and Jordi Estevadeordal, visited Dayton, Ohio to attend the Turbine Engine Technology Symposium (TETS). TETS is a forum where the United States turbine engine community gathers to review and discuss the latest technology advances achieved through the Versatile, Affordable, Advanced Turbine Engines (VAATE) Program. There were three categories:
1) General overview lectures on VAATE programs (ADVENT, AATE, HEETE, STELR, VCAT) by government organizations (USAF, ARFL, AFMC, US Army, ONR, DARPA, NASA, Navy, FAA, JSF) and perspective lectures by industry engine companies (Lockheed Martin, Northrop Grumman, Boeing, Honeywell, GE Aviation, Williams, Pratt & Whitney, Rolls-Royce/Liberty Works)
2) Technical workshops of most engine topics (alternate fuels, exhaust jet noise reduction, turbine durability, turbine instrumentation, compressor aero, combustors, probabilistic design, materials propulsion, etc)
3) Exhibitor’s booths including government and large and small companies
Jordi presented his work on Infrared (IR) Thermography in the ‘Turbine Durability’ session. The presentation was focused on multicolor pyrometry techniques for turbine prognosis, health monitoring, and diagnostics that allows the measurement of temperature and emissivity of the target simultaneously. The presentation included examples of measurements taken in actual engines: one from an aviation engine showing how multicolor pyrometry allowed measurement of the temperature and emissivity of the blade surfaces, and another from a power gas turbine showing how multicolor allowed the detection of spallation.
This session also included presentations by AFRL on their newly renovated Turbine Research Facility, and NASA on Heat Transfer Measurements in a linear cascade. A second turbine session, ‘Turbine Engine Instrumentation and Standards Technology’ focused on various instrumentation standards overviews such as: blade tip timing, temperature measurements using thermographic phosphors, dynamic pressure standards, and wireless data transmission in turbine engine cell environments.
As you can see, these sessions provide both government and industry the opportunity to understand the state of the art in the technology areas key to turbomachinery durability. Being at Global Research gives researchers a broad view of the industry while also allowing us to impact the most mission critical aspects of GE’s aircraft engines and gas turbines.