Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability


Book Description

Results from a series of experiments to investigate whether centrifugal compressor stability could be improved by injecting air through the diffuser hub surface are reported. The research was conducted in a 4:1 pressure ratio centrifugal compressor configured with a vane-island diffuser. Injector nozzles were located just upstream of the leading edge of the diffuser vanes. Nozzle orientations were set to produce injected streams angled at 8, 0 and +8 degrees relative to the vane mean camber line. Several injection flow rates were tested using both an external air supply and recirculation from the diffuser exit. Compressor flow range did not improve at any injection flow rate that was tested. Compressor flow range did improve slightly at zero injection due to the flow resistance created by injector openings on the hub surface. Leading edge loading and semi-vaneless space diffusion showed trends similar to those reported earlier from shroud surface experiments that did improve compressor flow range. Opposite trends are seen for hub injection cases where compressor flow range decreased. The hub injection data further explain the range improvement provided by shroud-side injection and suggest that different hub-side techniques may produce range improvement in centrifugal compressors. Skoch, Gary J. Glenn Research Center NASA/TM-2004-213182, ARL-TR-3158, GT2004-53618, E-14677




Design and Analysis of Centrifugal Compressors


Book Description

A comprehensive overview of fluid dynamic models and experimental results that can help solve problems in centrifugal compressors and modern techniques for a more efficient aerodynamic design. Design and Analysis of Centrifugal Compressors isacomprehensive overview of the theoretical fluid dynamic models describing the flow in centrifugal compressors and the modern techniques for the design of more efficient centrifugal compressors. The author — a noted expert in the field, with over 40 years of experience — evaluates relevant numerical and analytical prediction models for centrifugal compressors with special attention to their accuracy and limitations. Relevant knowledge from the last century is linked with new insights obtained from modern CFD. Emphasis is to link the flow structure, performance and stability to the geometry of the different compressor components. Design and Analysis of Centrifugal Compressors is an accessible resource that combines theory with experimental data and previous research with recent developments in computational design and optimization. This important resource Covers the basic information concerning fluid dynamics that are specific for centrifugal compressors and clarifies the differences with axial compressors Provides an overview of performance prediction models previously developed in combination with extra results from research conducted by the author Describes helpful numerical and analytical models for the flow in the different components in relation to flow stability, operating range and performance Includes the fundamental information for the aerodynamic design of more efficient centrifugal compressors Explains the use of computational fluid dynamics (CFD) for the design and analysis of centrifugal compressors Written for engineers, researchers and designers in industry as well as for academics specializing in the field, Design and Analysis of Centrifugal Compressors offers an up to date overview of the information needed for the design of more effective centrifugal compressors.




7th International Conference on Compressors and their Systems 2011


Book Description

This book contains the papers presented at the 7th International Conference on Compressors and their Systems at City University London in conjunction with the IMECHE. This conference is the ultimate global forum for reviewing the latest developments and novel approaches in compressor research. It features contributions from equipment manufacturers, suppliers, users and research organisations; these papers present developments in air, gas and refrigeration compressors; vacuum pumps; expanders; and related systems and components. Papers cover the design, development and operation of a wide range of compressors and expanders. Equipment manufacturers, suppliers, users and research organisations are all represented. Aspects covered include: present and future developments in scroll compressors; design and optimisation of screw compressors; latest thinking in oscillating and vane compressors; improving the function of valves; latest research in dynamic compressors; detailed analysis of reciprocating compressors; improved accuracy and usefulness of modelling techniques; developing better control of centrifugal compressors; and reducing unwanted noise and vibration. - Presents all the papers of the International Conference on Compressors and their Systems 2011 - Up to date papers on compressor technology improvements - The latest prediction modelling techniques are presented




8th International Conference on Compressors and their Systems


Book Description

This book contains the papers from the 2013 International Conference on Compressors and Their Systems, held from 9-10 September at City University London. The long-running conference series is the ultimate global forum for reviewing the latest developments and novel approaches in compressor research. High-quality technical papers are sourced from around the globe, covering technology development, operation, maintenance and reliability, safety and environmental impact, energy efficiency and carbon footprint, system integration and behaviour, upgrades and refurbishment, design and manufacture, education and professional development. All the papers are previously unpublished and constitute leading edge research. - Presents leading edge developments in compressor technology - Gives the latest prediction and modelling techniques - Details the new technology and machinery