Turbogas Engines Rotational Speed Estimation Using Acoustic and Vibrational Measurements

The overall objective of this work is the development and validation of a real-time algorithm to estimate turbogas engine rotational speeds by using accelerometric or microphonic measurements. The main advantage of this method is the absence of any intrusive installation on the engine and the fact that it might be implemented, as redundant measurement, in parallel to typical tachometric instrumentation. The developed code analyses the acquired FFT spectrum in order to identify characteristic frequencies of engine rotating components and automatically track their evolution. Experimental tests have been performed on an Allison 250C18 turboshaft engine at the Propulsion Laboratory of the University of Bologna and estimated values have been compared with tachometric measurements. Preliminary results have demonstrated the feasibility of the proposed code and an appreciable accuracy of obtained estimations through both microphone and accelerometer.