Solving Temperature Measurement Attrition in Turbine Engine Testing

08.30.2021 | Turbine Blades

In addition to optimizing performance and efficiency, turbine engine testing is heavily concerned with accurately determining part life and cooling air needed to optimize efficiency on critical components. 

This is because a high rate of heat transfer can have a profound effect on component longevity, amassing thermal fatigue over time from high-temperature differentials between start-up and shut-down temperatures. Even a surplus of just 20°C over the operating temperature limit on the surface of a 1st stage nozzle can radically impact turbine blade life throughout the engine (making blades rated for 24,000 operating hours drop to 8,000 effective operating hours, for example). 

More than just the turbine blades will be at risk, too. Thermal fatigue impacts all components in the hot gas path, from the combustor to the transition piece, nozzles, blades, and discs. Detection of hotspots and problematic localized rates of heat transfer are therefore critical in all turbine engine testing environments. But this doesn’t necessarily mean it will be easy.

Today’s Turbine Engine Testing Isn’t Easy — Or Cheap

The expensive and intrusive process for heat detection and component health monitoring in the turbine industry today lays a litany of problems on test engineers. Some of them include:

  • Accuracy issues at higher temperatures with optical/IR instruments
  • Test data that records only the highest temperature reached during a cycle
  • Cumbersome machining and drilling to route thermocouple wire harnesses
  • Sensors that may work in test stands, but not in the field for continued monitoring
  • Costs that make frequent temperature monitoring in the engine development cycle impractical
  • Time-consuming engine teardowns for sensor installation
  • Low rates of measurement survivability (necessitating replacement)
  • Longer development cycles

These complications can sometimes even necessitate waiting for a failure analysis, rather than engaging in pre-emptive, continuous heat monitoring throughout the engine during the engine testing phase of turbine development.

The Next-Gen Solution: TurboTrack: Rotating Wireless Temperature Measurement System

The wireless RF sensor system developed by Sensatek—in cooperation with funding from the National Science Foundation and NASA—is set to change the game for test engineers and the turbine development cycle.

Whereas previous instruments may have required engine modification or deconstruction to route thermocouple wires, our sensors merely require the insertion of a high-temperature antenna through the slip ring for completely wireless communication with hundreds of sensor channels. The sensors themselves are low-profile ceramic-based patches with a fully customizable size (often smaller than a postage stamp) and only fractions of a millimeter in thickness. This form factor allows for easy deployment in hard-to-reach places without dismantling the turbine engine.

The RF technology used by the Sensatek sensor system is both more sensitive and more accurate than prior solutions, with the addition of long-term measurement survivability in the harshest of all man-made environments.

The result? Heat detection and health monitoring during turbine engine testing is much improved:

  • Drastically reduced costs per installed measurement
  • Faster installation and setup
  • Improved prediction of blade life and maintenance needs
  • Accelerated engine development cycles
  • Continuous, real-time tracking of component surface temperatures for a detailed historical model
  • Capability to deploy sensors in the field for the full duration of engine life
  • Accuracy even at extreme temperatures (up to 1,700°C for short durations)

The potential benefits for jet engine testing, power generation, and other turbine applications are enormous. Temperature is no longer the most challenging measurement to collect. Contact Sensatek today to learn more about how TurboTrack can improve efficiency and data quality throughout turbine engine testing.

https://www.sensatek.com/wp-content/uploads/2020/03/Sensatek-Datasheet.pdf