Experimental investigation of characteristic frequency in compressor surge of a turbocharger

Exhaust turbocharger is one of the most important components of diesel engine. The surge of such an exhaust turbocharger could cause serious damage or even failure during the operation. Therefore, it is of great significance to detect signs when surge initially occurs. In this article, the characteristic frequencies in sound pressure and structural vibration are investigated to detect the surge of a turbocharger. An extensive data analysis in both time and frequency domain will be made to find out the characteristics of the surge phenomenon for such an exhaust turbocharger. It is observed that the rotor of such a turbocharger will be in resonance condition when the surge occurs. In addition, a method based on the sound energy in the characteristics frequency is proposed to diagnose and predict surge of the compressor. This method can efficiently alarm the surge of such turbocharger without installing the pressure sensor which will damage its structure.