A Computational Model for Multistage Axial Compressor Design PDF Download

Author: Arnaud Irving Wisnia
Publisher:
ISBN:
Category :
Languages : en
Pages : 221

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Author: Chaithanya Mamidoju
Publisher:
ISBN:
Category :
Languages : en
Pages : 41

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Turbomachines are used extensively in Aerospace, Power Generation, and Oil & Gas Industries. Efficiency of these machines is often an important factor and has led to the continuous effort to improve the design to achieve better efficiency. The axial flow compressor is a major component in a gas turbine with the turbine's overall performance depending strongly on compressor performance. Traditional analysis of axial compressors involves through flow calculations, isolated blade passage analysis, Quasi-3D blade-to-blade analysis, single-stage (rotor-stator) analysis, and multi-stage analysis involving larger design cycles. In the current study, the detailed flow through a 15 stage axial compressor is analyzed using a 3-D Navier Stokes CFD solver in a parallel computing environment. Methodology is described for steady state (frozen rotor stator) analysis of one blade passage per component. Various effects such as mesh type and density, boundary conditions, tip clearance and numerical issues such as turbulence model choice, advection model choice, and parallel processing performance are analyzed. A high sensitivity of the predictions to the above was found. Physical explanation to the flow features observed in the computational study are given. The total pressure rise verses mass flow rate was computed.

Author: James E. Crouse
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 112

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A code for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis codes is presented. The aerodynamic solution gives velocity diagrams on selected streamlines of revolution at the blade row edges. Blading is defined from stacked blade elements associated with the selected streamlines. The blade element inlet and outlet angles are established through empirical incidence and deviation angle adjustments to the relative flow angles of the velocity diagrams. The blade element centerline is composed of two segments tangentially joined at a transition point. The local blade angle variation of each segment can be specified with a fourth-degree polynomial function of path distance. Blade element thickness also can be specified with fourth-degree polynomial functions of path distance from the maximum thickness point.

Author: Mohamed Omar Hadjout
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Author: A. C. Bryans
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721937349
Category :
Languages : en
Pages : 206

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This thesis presents the conceptualization and development of a computational model for describing three-dimensional non-linear disturbances associated with instability and inlet distortion in multistage compressors. Specifically, the model is aimed at simulating the non-linear aspects of short wavelength stall inception, part span stall cells, and compressor response to three-dimensional inlet distortions. The computed results demonstrated the first-of-a-kind capability for simulating short wavelength stall inception in multistage compressors. The adequacy of the model is demonstrated by its application to reproduce the following phenomena: (1) response of a compressor to a square-wave total pressure inlet distortion; (2) behavior of long wavelength small amplitude disturbances in compressors; (3) short wavelength stall inception in a multistage compressor and the occurrence of rotating stall inception on the negatively sloped portion of the compressor characteristic; (4) progressive stalling behavior in the first stage in a mismatched multistage compressor; (5) change of stall inception type (from modal to spike and vice versa) due to IGV stagger angle variation, and "unique rotor tip incidence" at these points where the compressor stalls through short wavelength disturbances. The model has been applied to determine the parametric dependence of instability inception behavior in terms of amplitude and spatial distribution of initial disturbance, and intra-blade-row gaps. It is found that reducing the inter-blade row gaps suppresses the growth of short wavelength disturbances. It is also concluded from these parametric investigations that each local component group (rotor and its two adjacent stators) has its own instability point (i.e. conditions at which disturbances are sustained) for short wavelength disturbances, with the instability point for the compressor set by the most unstable component group. For completeness, the methodology has been extended

Author: Louis M. Larosiliere
Publisher:
ISBN:
Category : Compressors
Languages : en
Pages : 36

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Author: Robert O. Bullock
Publisher:
ISBN:
Category : Axial flow compressors
Languages : en
Pages : 552

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Author: Shawn A. Miller
Publisher:
ISBN: 9781423563297
Category : Axial flow compressors
Languages : en
Pages : 94

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Book Description
The development of jet engines has become an integral part of maintaining air superiority. In order to achieve the most advanced engine, research has turned to traditional optimization methods to aid in creating new engine designs. To develop simplified mathematical models representative of the engine, the engine can be separated into its components. A jet engine has three major elements, the compressor, combustion chamber and turbine. This research attempts to make an initial analysis of a two stage compressor to determine values of blade angles and spacing to chord ratios for both stages that produce the highest possible efficiency for the overall two stage compressor. A pitch line model is developed for a two stage compressor and is used in conjunction with a optimization method to solve for the on design air angles and spacing to chord ratios. The results of the model were compared to examples available in current literature to ensure the model properly represents a compressor stage. The off design performance of the results was calculated to determine how the designs for on design operated under off design conditions. Since practical compressors are made up of many stages, consideration is given to which optimization method would be most useful in solving for a multistage compressor.

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722931087
Category :
Languages : en
Pages : 24

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An existing computer code that determines the flow path for an axial-flow compressor either for a given number of stages or for a given overall pressure ratio was modified for use in air-breathing engine conceptual design studies. This code uses a rapid approximate design methodology that is based on isentropic simple radial equilibrium. Calculations are performed at constant-span-fraction locations from tip to hub. Energy addition per stage is controlled by specifying the maximum allowable values for several aerodynamic design parameters. New modeling was introduced to the code to overcome perceived limitations. Specific changes included variable rather than constant tip radius, flow path inclination added to the continuity equation, input of mass flow rate directly rather than indirectly as inlet axial velocity, solution for the exact value of overall pressure ratio rather than for any value that met or exceeded it, and internal computation of efficiency rather than the use of input values. The modified code was shown to be capable of computing efficiencies that are compatible with those of five multistage compressors and one fan that were tested experimentally. This report serves as a users manual for the revised code, Compressor Spanline Analysis (CSPAN). The modeling modifications, including two internal loss correlations, are presented. Program input and output are described. A sample case for a multistage compressor is included. Glassman, Arthur J. Unspecified Center NAG3-1165; RTOP 505-69-50...