Prediction of centrifugal compressor instabilities for internal combustion engines operating cycle simulation

Abstract

Centrifugal compressors, which serve the purpose of internal combustion engines (ICE) supercharging, have a region of unstable operation. The compressor instabilities can be distinguished as rotating stall, mild, or deep surge, depending on the compression system parameters. All these types of compressor operation should be avoided for engine durability and long service life. Therefore, it is important to provide fast, stable, and correct prediction of compressor instabilities at ICE operating cycle simulation. The experimental research was conducted for an aircraft engine compressor to measure compressor performance map in the region of unstable operation, which is usually never provided by the manufacturer, and to study the compression system operation in the mild and deep surge modes. A mathematical model was developed, based on the Moore-Greitzer approach together with the modified equation of the compressor outlet pipe airflow acceleration, and integrated into the Blitz- PRO service for ICE steady and transient operation simulation. It is shown that the suggested mathematical model correlates well with the experimental data for the compressor testbench case. The application of the developed mathematical model provides fast and stable calculations and prediction of the type of compression system instability