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].




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.













An Investigation of Surge in a High-Speed Centrifugal Compressor Using Digital Piv


Book Description

Compressor stall is a catastrophic breakdown of the flow in a compressor, which can lead to a loss of engine power, large pressure transients in the inlet/nacelle and engine flameout. The implementation of active or passive strategies for controlling rotating stall and surge can significantly extend the stable operating range of a compressor without substantially sacrificing performance. It is crucial to identify the dynamic changes occurring in the flow field prior to rotating stall and surge in order to successfully control these events. Generally, pressure transducer measurements are made to capture the transient response of a compressor prior to rotating stall. In this investigation, Digital Particle Imaging Velocimetry (DPIV) is used in conjunction with dynamic pressure transducers to simultaneously capture transient velocity and pressure measurements in the non-stationary flow field during compressor surge. DPIV is an instantaneous, planar measurement technique which is ideally suited for studying transient flow phenomena in high speed turbomachinery and has been used previously to successfully map the stable operating point flow field in the diffuser of a high speed centrifugal compressor. Through the acquisition of both DPIV images and transient pressure data, the time evolution of the unsteady flow during surge is revealed.Wernet, Mark P. and Bright, Michelle M. and Skoch, Gary J.Glenn Research CenterCENTRIFUGAL COMPRESSORS; ROTATING STALLS; PARTICLE IMAGE VELOCIMETRY; PRESSURE MEASUREMENT; DYNAMIC PRESSURE; PRESSURE SENSORS; TRANSIENT PRESSURES; UNSTEADY FLOW




Gas Turbines for Electric Power Generation


Book Description

Everything you wanted to know about industrial gas turbines for electric power generation in one source with hard-to-find, hands-on technical information.