Modeling and control of compressor flow instabilities

Abstract

Stable operation of both axial and radial compressors is constrained by the occurence of aerodynamic flow instabilities: rotating stall and surge. Developments in the understanding of the physics behind these instabilities and ideas of how t o stabilize the compressor system, have opened the door t o a new era in the field of compressor control.This study gives an overview of the current state in modeling and control of surge and rotating stall in axial and radial compressors. It summarizes different types of aerodynamic flow instabilities that can occur in these machines. Compressor performance is discussed on the basis of compressor maps and important features of these instabilities are treated. But, this work focuses on active control systems applied in experimental systems. Compressor models that are used frequently in controller designs are described and the effect of assumptions on the prediction capability of these models is discussed. Furthermore, this report deals with control concepts t o guarantee stable operation and an outline is given of sensors, actuators and controllers applied in laboratory set-ups.The main contribution of this study is the comparison of aerodynamical flow instabilities found in axial and radial compressors, of several models, and of controllers implemented on experimental set-ups. It appeared that the behavior of a compressor system subsequent to instability onset is reasonably grasped but the considered models can not describe all types of instabilities encountered. Nevertheless, the Moore-Greitzer model seems an useful starting point for further research since it describes the compressor behavior subsequent t o the onset of rotating stall and surge. A better understanding of the mechanism(s) behind the onset of these instabilities may allow refinements to existing models and may give insights into new control methods. Currently, apart from a few exceptions, only complex-valued proportional feedback controllers are used. More advanced, nonlinear controllers are expected to improve the performance of the compressor system.

Research on Forecasting of the Compressor Geometric Variable System Based on the MAE Model

“…Figure 1 shows the general structure of aeroengines. In the compressor, the entering fluid will be pressurized by first accelerating it via the kinetic energy imparted in the rotors, and then diverging channels will slow the fluid down so that the kinetic energy could be converted into potential energy [7]. However, rotating stalls and surges will make the system unstable, which means the aircraft's airworthiness would be influenced by the unsecured status of the engine.…”

Finite-time adaptive sliding mode control for compressor surge with uncertain characteristic in the presence of disturbance

“…Concerning the destructive effects of the surge phenomenon in the compression systems, significant attempts have been made to control this instability in centrifugal compressors. Two principal categories of surge instability control include surge prevention and surge active control (Epstein et al, 1989;Willems & De Jager, 1999). Due to the drawbacks associated with the application of the surge preventive method that leads to the compressor's efficiency loss, active surge control has emerged as a more effective tool for compensation of surge instability.…”

Compressor surge control using a new robust adaptive method in the presence of uncertainty and unmatched disturbance

“…Due to the destructive effects of the surge phenomenon on the compression system, its control is one of the most important concerns regarding compressors and it is one of the most popular topics in the field of these practical systems (Arthur et al, 2019;Guan et al, 2019;Moore et al, 2018). Two major categories for controlling surge instability are surge prevention and active surge CONTACT Mohammad Malekgoudarzi mohammad.malekgoudarzi@gmail.com control (Epstein et al, 1989;Willems, 1999). Due to the disadvantages of the surge prevention method in reducing the compressor efficiency, active surge control is the preferred method for controlling this instability.…”