Session: 06-11 Advanced Simulation and testing

Paper Number: 152436

Experimental Analysis of the Dynamic Behavior of Centrifugal Compressors During the Transition From Stable to Surge Conditions 

Centrifugal compressors are crucial components in several industrial applications, making it fundamental to understand their behavior, particularly under incipient surge conditions, to optimize their operating region. Surge is a phenomenon that results in significant fluctuations in pressure and mass flow rate, causing instability and potentially leading to dangerous vibrations and thermal stress. This study examines surge transitions in centrifugal compressors by utilizing a comprehensive approach that combines dynamic mass flow rate and pressure measurements, obtained through anemometric fiber film probes and high-frequency piezoresistive pressure transducers, along with vibroacoustic data collected from micro mono-axial accelerometers and microphones.

To better understand the transition from stable to unstable compressor operation, an extensive experimental campaign was conducted on a centrifugal compressor at the at the University of Genoa test bench for components of propulsion system. These tests involved both steady-state and transient measurements to characterize the compressor's behavior in stable regions, during incipient surge, and under deep surge conditions.

The acquired experimental data on the compressor’s fluid dynamics and mechanical response were analyzed using frequency and time-frequency techniques to define the compressor operation as stable or unstable. Time-domain synchronous average was found to be effective in identifying incipient surge conditions. Additionally, statistical methods such as spectral kurtosis and variance were also employed proving their reliability is surge detection. Finally, coherence functions calculated using multiple sensors in both stable and unstable conditions demonstrated strong potential as a tool for surge detection.

The main objective of this study is to provide insights that support the development of advanced control strategies and predictive protocols, helping to mitigate surge-related problems and enhance the overall performance and reliability of systems where centrifugal compressors are installed.

Presenting Author: Paolo Silvestri University of Genoa

Presenting Author Biography: Paolo Silvestri got in 1993 the Master Degree in Mechanical Engineering with honors at the University of Genova (Italy). He obtained a Ph.D. in Fluid Machinery Engineering in 1998. Military service as a naval officer (technical military office in Milano)
Present position: researcher/assistant professor at Polytechnic School of the University of Genova. Chief Executive Officer of SIT technologies, a recognized spin off company of the University of Genova born within the Department of Mechanical Engineer, whose core technology is related to innovative solution based on bladeless Tesla turbine. External consultant for Siemens PLM Software (LMS).
The research activity deals with aspects on analysis and optimization of the vibrational behavior of rotating machines, machine condition monitoring and fault diagnostics, structural dynamics testing and advanced techniques for system identification.
Teaching activity: Applied Mechanics, Mechanics of Rail Vehicle, Modelling and Simulation of Mechanical Systems, Mechanical Vibration. Lectures for the school of Doctorate and for the Master in Industrial Plant Engineering and Technologies (MIPET).

Authors:

Vittorio Usai University of Genoa
Silvia Marelli University of Genoa
Paolo Silvestri University of Genoa