Compressor stall is a performance issue which arises when a compressor experiences flow separation and a region of stalled air circulates around the engine at roughly half of the rotor rotation speed. Compressor stall can lead to compressor surge, which can result in compressor failure.
Picture above: Impact of an axi-symmetric compressor stall (a.k.a. surge). This instance of compressor surge occurred on a Boeing C-17A in 2006.
The project objective is to develop a non-intrusive system capable of detecting the onset of compressor stall or stall precursors in gas turbine engines for the purpose of enabling the avoidance of a damaging surge event.
The proposed solution is a rotating stall detection system using optical measurement. The system must notify the engine control system for taking corrective action, so as to avoid or reduce stall/surge damage.
Prime Photonics is developing the Surge and Stall Identification (SUSTAIN) system which is measuring both blade by blade deflection and twist/untwist to detect a stall event. The SUSTAIN system can detect stall precursors by detecting the unsteadiness in the blade deflection and twist/untwist data.
Image Above: twist angle variation between a loaded vs. stall blade
Testing and research are ongoing. Testing so far has demonstrated the ability to detect a pre-stall event 40 ms before full stall. The optical probes and stall detection algorithm have been improved to more effectively detect the short-lived transient patterns associated with stall from the large vibration data. Real-time stall detection instruments are under development to locate and detect stall conditions.
Picture above: CAD rendering of a stall detection probe (manufactured and successfully tested)
To learn more about our stall detection research please contact us by filling out the form below.