Bifurcation Analysis of Surge and Rotating Stall in Axial Flow Compressors


Book Description

These results are used to reconstruct Greitzer's (1976) findings regarding the manner in which post-instability behavior depends on system parameters. Moreover, the results provide significant new insight deemed valuable in the prediction, analysis and control of stall instabilities in gas turbine jet engines."




Compressor Surge and Rotating Stall


Book Description

The series Advances in Industrial Control aims to report and encourage technology transfer in control engineering. The rapid development of control technology impacts all areas of the control discipline. New theory, new controllers, actuators, sensors, new industrial processes, computer methods, new applications, new philosophies . . . , new challenges. Much of this development work resides in industrial reports, feasibility study papers and the reports of advanced collaborative projects. The series offers an opportunity for researchers to present an extended exposition of such new work in all aspects of industrial control for wider and rapid dissemination. Operating plant as close as possible to constraint boundaries so often brings economic benefits in industrial process control. This is the conundrum at the heart of this monograph by Tommy Gravdahl and Olav Egeland on stall control for compressors. Operation of the compressor closer to the surge line can increase operational efficiency and flexibility The approach taken by the authors follows the modern control system paradigm: -physical understanding, detailed modelling and simulation studies and finally control studies. The thoroughness of the presentation, bibliography and appendices indicates that the volume has all the hallmarks of being a classic for its subject. Despite the monograph's narrow technical content, the techniques and insights presented should appeal to the wider industrial control community as well as the gas turbine/compressor specialist. M. J. Grimble and M. A.




Bifurcation Based Nonlinear Feedback Control for Rotating Stall in Axial Compressors


Book Description

Classical bifurcation analysis for nonlinear dynamics is used to derive a nonlinear feedback control law that eliminates the hysteresis loop associated with rotating stall and extends the stable operating range in axial compressors. The proposed control system employs pressure rise as output measurement and throttle position as actuating signal for which both sensor and actuator exist in the current configuration of axial compressors. Thus our results provide a practical solution for rotating stall control in axial compressors.







Active Control of Compressor Stall Inception: A Bifurcation-Theoretic Approach


Book Description

Active control of the onset of stall instabilities in axial flow compressors is pursued using bifurcation analysis of a dynamical model proposed by Moore and Greitzer (1983). This model consists of three ordinary differential equations with state variables being the mass flow rate, pressure rise, and the amplitude of the first harmonic mode of the asymmetric component of the flow, The model is found to exhibit a stationary (pitchfork) bifurcation at the inception of stall, resulting in hysteresis. Using the throttle opening as a control, analysis of the linearized system at stall shows that the critical mode (zero eigenvalue) is unaffected by linear feedback. Hence, nonlinear tools must be used to achieve stabilization. A quadratic feedback control law using measurement of asymmetric dynamics is proposed which stabilizes the bifurcation and eliminates the undesirable hysteretic behavior.




Bifurcation Control


Book Description

Bifurcation control refers to the task of designing a controller that can modify the bifurcation properties of a given nonlinear system, so as to achieve some desirable dynamical behaviors. There exists no similar control theory-oriented book available in the market that is devoted to the subject of bifurcation control, written by control engineers for control engineers. World-renowned leading experts in the field provide their state-of-the-art survey about the extensive research that has been done over the last few years in this subject. The book is not only aimed at active researchers in the field of bifurcation control and its applications, but also at a general audience in related fields.




Compressor Surge and Stall


Book Description

High efficiency axial and centrifugal compressors are important in fields as diverse as aircraft engines, superchargers and turbochargers, process and refrigeration compressors. Compressors must achieve high efficiency in blade rows in diffusing flow fields. Of equal and sometimes greater importance is the range os stable operation of the compressor. Blade row stall characteristics determine the limit os stable operation. Blading can stall uniformly with symmetric flow breakdown or asymmetrically in rotating stall, wich propagates around the periphery of the blade row. Depending on aerodynamic conditions, surge may occur instead of, in concert with, or subsequent to blade row stall. The transient breakdown and recovery of aerodynamic loading not only limits compressor performance but also leads to mechanical failures caused by the vibrational loads imposed on the blades. There is no need to know what initiates these performance limits so that surge and stall margins can be optimized and control strategies can be planned. the first step toward understanding is to be knowledgeable about he physical processes occurring during surge and stall. This will permit the designer to anticipate variable geometry needs such as variable inlet guide vanes, variable statuors, and bleed port strategies. Theoritical treatment is far from being well established, however, there are many approaches discussed in the literature. This book is a unique reference to the subject matter. Physical descriptions of the phenomena are given, test results are presented, and analytical studies are discussed. There has been much written about the experimental investigations and theoretical treatments related to surge and stall. To assist those who would pursue advancements in furthering ou knowledge of surge and stall, it seemed appropriate to have a resource that contains a compendium of information on this subject. That is the purpose of this book. [Source : d'après la 4e de couverture].




Practical Bifurcation and Stability Analysis


Book Description

Probably the first book to describe computational methods for numerically computing steady state and Hopf bifurcations. Requiring only a basic knowledge of calculus, and using detailed examples, problems, and figures, this is an ideal textbook for graduate students.