scholarly journals Experimental and Computational Investigation of the NASA Low-Speed Centrifugal Compressor Flow Field

1992 ◽  
Author(s):  
M. D. Hathaway ◽  
R. M. Chriss ◽  
J. R. Wood ◽  
A. J. Strazisar
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Surface Flow ◽  
Computational Investigation ◽  
Complex Flow ◽  
Impeller Blade ◽  
Low Speed ◽  
Laser Anemometry

An experimental and computational investigation of the NASA Low-Speed Centrifugal Compressor (LSCC) flow field has been conducted using laser anemometry and Dawes’ 3D viscous code. The experimental configuration consists of a backswept impeller followed by a vaneless diffuser. Measurements of the three–dimensional velocity field were acquired at several measurement planes through the compressor. The measurements describe both the throughflow and secondary velocity field along each measurement plane. In several cases the measurements provide details of the flow within the blade boundary layers. Insight into the complex flow physics within centrifugal compressors is provided by the computational analysis, and assessment of the CFD predictions is provided by comparison with the measurements. Five-hole probe and hot-wire surveys at the inlet and exit to the rotor as well as surface flow visualization along the impeller blade surfaces provide independent confirmation of the laser measurement technique.

scholarly journals Experimental and Computational Investigation of the NASA Low-Speed Centrifugal Compressor Flow Field

1993 ◽  
Vol 115 (3) ◽  
pp. 527-541 ◽  
Author(s):  
M. D. Hathaway ◽  
R. M. Chriss ◽  
J. R. Wood ◽  
A. J. Strazisar
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Surface Flow ◽  
Computational Investigation ◽  
Complex Flow ◽  
Centrifugal Compressors ◽  
Impeller Blade ◽  
Low Speed

An experimental and computational investigation of the NASA Low-Speed Centrifugal Compressor (LSCC) flow field has been conducted using laser anemometry and Dawes’ three dimensional viscous code. The experimental configuration consists of a backswept impeller followed by a vaneless diffuser. Measurements of the three-dimensional velocity field were acquired at several measurement planes through the compressor. The measurements describe both the throughflow and secondary velocity field along each measurement plane. In several cases the measurements provide details of the flow within the blade boundary layers. Insight into the complex flow physics within centrifugal compressors is provided by the computational analysis, and assessment of the CFD predictions is provided by comparison with the measurements. Five-hole probe and hot-wire surveys at the inlet and exit to the rotor as well as surface flow visualization along the impeller blade surfaces provide independent confirmation of the laser measurement technique. The results clearly document the development of the throughflow velocity wake, which is characteristic of unshrouded centrifugal compressors.

Design and Off-Design Numerical Investigation of a Transonic Double-Splitter Centrifugal Compressor

2008 ◽  
Author(s):  
Michele Marconcini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Seiichi Ibaraki
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Cross Sections ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Complex Flow ◽  
Flow Measurements ◽  
Vaned Diffuser

The flow field of a high pressure ratio centrifugal compressor for turbocharger applications is investigated using a three-dimensional Navier-Stokes solver. The compressor is composed of a double-splitter impeller followed by a vaned diffuser. The flow field of the transonic open-shrouded impeller is highly three-dimensional, and it is influenced by shock waves, tip leakage vortices and secondary flows. Their interactions generate complex flow structures which are convected and distorted through the impeller blades. Both steady and unsteady computations are performed in order to understand the physical mechanisms which govern the impeller flow field while the operation ranges from choke to surge. Detailed Laser Doppler Velocimetry (LDV) flow measurements are available at various cross-sections inside the impeller blades at both design and off-design operating conditions.

Numerical Investigation of a Transonic Centrifugal Compressor

2006 ◽  
Author(s):  
Michele Marconcini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Seiichi Ibaraki
Keyword(s):  
Shock Waves ◽  
Flow Field ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Tip Clearance ◽  
Complex Flow ◽  
Low Velocity ◽  
Flow Measurements

A three-dimensional Navier-Stokes solver is used to investigate the flow field of a high pressure ratio centrifugal compressor for turbocharger applications. Such a compressor consists of a double-splitter impeller followed by a vane diffuser. The inlet flow to the open shrouded impeller is transonic, thus giving rise to interactions between shock waves and boundary layers and between shock waves and tip leakage vortices. These interactions generate complex flow structures which are convected and distorted through the impeller blades. Detailed Laser Doppler Velocimetry (LDV) flow measurements are available at various cross sections inside the impeller blades highlighting the presence of low velocity flow regions near the shroud. Particular attention is focused on understanding the physical mechanisms which govern the flow phenomena in the near shroud region. To this end numerical investigations are performed using different tip clearance modelizations and various turbulence models, and their impact on the computed flow field is discussed.

A Three-Dimensional Inverse Method for Turbomachinery: Part I—Theory

1990 ◽  
Vol 112 (3) ◽  
pp. 346-354 ◽  
Author(s):  
J. E. Borges
Keyword(s):  
Velocity Field ◽  
Inverse Method ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Inverse Methods ◽  
Meridional Section ◽  
Low Speed ◽  
Present Procedure ◽  
Blade Row ◽  
The Mean

There are surprisingly few inverse methods described in the literature that are truly three dimensional. Here, one such method is presented. This technique uses as input a prescribed distribution of the mean swirl, i.e., radius times mean tangential velocity, given throughout the meridional section of the machine. In the present implementation the flow is considered inviscid and incompressible and is assumed irrotational at the inlet to the blade row. In order to evaluate the velocity field inside the turbomachine, the blades (supposed infinitely thin) are replaced by sheets of vorticity, whose strength is related to the specified mean swirl. Some advice on the choice of a suitable mean swirl distribution is given. In order to assess the usefulness of the present procedure, it was decided to apply it to the design of an impeller for a low-speed radial-inflow turbine. The results of the tests are described in the second part of this paper.

Analytical Theory of Three Dimensional Flow in Centrifugal Compressors

1981 ◽  
Vol 23 (4) ◽  
pp. 179-191 ◽  
Author(s):  
C. Bosman
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Surface Flow ◽  
Centrifugal Compressors ◽  
Three Dimensional Flow ◽  
Stream Tube ◽  
Stream Surface ◽  
Dimensional Flow ◽  
Passage Vortex ◽  
Turbomachine Blade

Inviscid, compressible flow along a rotating elemental stream-tube is taken as a model for flow through a turbomachine blade passage. For this model an analytic expression for the relative secondary vorticity of the flow is derived which permits the mean stream-surface twist about the tube axis to be evaluated. This twist implies a migration of the fluid particles from one tube corner to the contiguous tube corner, a flow feature suppressed by all existing stream-sheet flow calculations in turbomachine blade rows. The analysis is applied to a centrifugal compressor configuration where the effects on the secondary flow of hub/shroud geometry, blade shape, compressibility, and meridional diffusion are investigated. The stream-surface twist, not being primarily dependent upon the elemental nature of the stream-tube is taken as a measure of stream-surface twist and consequent surface flow migration in finite blade passages. The levels of twist obtained from the analysis are similar to those obtained in three dimensional flow calculations using primitive variables as illustrated by Bosman (1) (2)‡ and show that existing streamsheet and streamsheet stacking methods, all of which suppress the relative passage vortex are an inadequate model of the flow in centrifugal compressors. The analysis clearly shows that contrary to common assumption, centrifugal compressor impellers are capable of generating a passage vortex in the same direction as that of blade rotation.

scholarly journals Three-dimensional hydrodynamics numerical of wind-driven circulations in Danjiangkou Reservoir

2018 ◽  
Vol 246 ◽  
pp. 02021
Author(s):  
Jie Zhu ◽  
Jin Quan ◽  
Xiaohui Lei ◽  
Xia Yue ◽  
Yang Duan
Keyword(s):  
Wind Speed ◽  
Flow Field ◽  
Potential Flow ◽  
Flow Direction ◽  
Three Dimensional ◽  
Surface Flow ◽  
Surface Velocity ◽  
Wind Condition ◽  
Reservoir Area ◽  
Danjiangkou Reservoir

This paper focuses on the analysis of the flow field of Danjiangkou Reservoir under the action of wind stress. Based on the analysis of the annual wind field data of Danjiangkou Reservoir, the three-dimensional hydrodynamic model of Danjiangkou Reservoir was established. The distribution of water flow field in the reservoir area under five different wind directions and two different wind speeds was studied. The simulation results were compared with the flow field without wind. The results show that when the wind speed in the reservoir area is 3.3m/s, the surface velocity and flow direction change less under the same wind conditions as the potential flow direction. Under the wind condition opposite to the potential flow direction, the reservoir area is locally generated. The small circulation and surface flow are more disordered; when the wind speed reaches 10.0m/s, under the same wind condition as the potential flow direction, the surface velocity of the reservoir area increases significantly. Under the wind condition opposite to the direction of the potential flow, a stable counterclockwise circulation is generated, and the wind direction dominates the surface layer. seriously affecting the flow field distribution in the reservoir area. The research results in this paper can provide support for the reservoir in the formulation of emergency water pollution emergency strategy and the formulation of real-time scheduling plan.

An Approximate Three-Dimensional Aerodynamic Design Method for Centrifugal Impeller Blades

1990 ◽  
Vol 112 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Design Procedure ◽  
Taylor Series Expansion ◽  
Centrifugal Impeller ◽  
Aerodynamic Design ◽  
Impeller Blade ◽  
Blade Geometry

An aerodynamic design method, which is based on the Mean Stream Surface Method (MSSM), has been developed for designing centrifugal compressor impeller blades. As a component of a CAD system for centrifugal compressor, it is convenient to use the presented method for generating impeller blade geometry, taking care of manufacturing as well as aerodynamic aspects. The design procedure starts with an S2m indirect solution. Afterward from the specified S2m surface, by the use of Taylor series expansion, the blade geometry is generated by straight-line elements to meet the manufacturing requirements. Simultaneously, the fluid dynamic quantities across the blade passage can be determined directly. In terms of these results, the designer can revise the distribution of angular momentum along the shroud and hub, which are associated with blade loading, to get satisfactory velocities along the blade surfaces in order to avoid or delay flow separation.

Development and Industrial Application of the “All-Over-Controlled Vortex Distribution Method” for Designing Radial and Mixed Flow Impellers

1992 ◽  
Author(s):  
S. J. Wang ◽  
M. J. Yuan ◽  
G. Xi ◽  
S. X. Liu ◽  
D. T. Qi ◽  
...  
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Inverse Method ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Mixed Flow ◽  
Distribution Method ◽  
Stream Surface ◽  
Surface Theory ◽  
Performance Curves

Sixteen years ago an inverse method of designing radial, mixed flow impellers was proposed by the first author of this paper, which was based on a quasi-three-dimensional stream surface theory. The contradictions between the full controlling of the flow field in the whole impeller and the designed bables’ smooth machinability can be perfectly resolved with the above method (So it is called “all-over-controlled vortex distribution method”). This paper presents the developments and industrial applications of the above method in the last decade. Two single centrifugal compressor model stages with the 3-D impellers designed by this method are studied in detail, and several performance curves of the multistage centrifugal compressors designed by this method are also presented.

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