Status of Centrifugal Impeller Internal Aerodynamics—Part I: Inviscid Flow Prediction Methods

1980 ◽  
Vol 102 (3) ◽  
pp. 728-737 ◽  
Author(s):  
D. Adler

Recent developments in inviscid prediction methods of internal flow fields of centrifugal impellers and related flows are critically reviewed. The overall picture which emerges provides the reader with a state-of-the-art perspective on the subject. Restricting simplifying assumptions of the various methods are identified to stimulate future research. Topics included in this review are: two-dimensional subsonic and transonic inviscid flows as well as three-dimensional inviscid flows.

1980 ◽  
Vol 102 (3) ◽  
pp. 738-746 ◽  
Author(s):  
D. Adler

Recent developments in internal viscous aerodynamics of centrifugal impellers and related flows are critically reviewed. The overall picture which emerges provides the reader with a state-of-the-art perspective on the subject. Gaps in understanding are identified to stimulate future research. Topics included in this review are: experimental work carried out in the last decade, the structure of turbulence in curved rotating passages and solution of viscous flow problems in impellers.


1993 ◽  
Vol 115 (2) ◽  
pp. 283-295 ◽  
Author(s):  
W. N. Dawes

This paper describes recent developments to a three-dimensional, unstructured mesh, solution-adaptive Navier–Stokes solver. By adopting a simple, pragmatic but systematic approach to mesh generation, the range of simulations that can be attempted is extended toward arbitrary geometries. The combined benefits of the approach result in a powerful analytical ability. Solutions for a wide range of flows are presented, including a transonic compressor rotor, a centrifugal impeller, a steam turbine nozzle guide vane with casing extraction belt, the internal coolant passage of a radial inflow turbine, and a turbine disk cavity flow.


1981 ◽  
Vol 103 (2) ◽  
pp. 367-372 ◽  
Author(s):  
J. Moore ◽  
J. G. Moore

A partially-parabolic calculation procedure is used to calculate flow in a centrifugal impeller. This general-geometry, cascade-flow method is an extension of a duct-flow calculation procedure. The three-dimensional pressure field within the impeller is obtained by first performing a three-dimensional inviscid flow calculation and then adding a viscosity model and a viscous-wall boundary condition to allow calculation of the three-dimensional viscous flow. Wake flow, resulting from boundary layer accumulation in an adverse reduced-pressure gradient, causes blockage of the impeller passage and results in significant modifications of the pressure field. Calculated wake development and pressure distributions are compared with measurements.


Author(s):  
Mou-jin Zhang ◽  
Chuan-gang Gu ◽  
Yong-miao Miao

The complex three-dimensional flow field in a centrifugal impeller with low speed is studied in this paper. Coupled with high–Reynolds–number k–ε turbulence model, the fully three–dimensional Reynolds averaged Navier–Stokes equations are solved. The Semi–Implicit Method for Pressure–Linked Equations (SIMPLE) algorithm is used. And the non–staggered grid arrangement is also used. The computed results are compared with the available experimental data. The comparison shows good agreement.


Author(s):  
J. H. G. Howard ◽  
Colin Osborne ◽  
David Japikse

A crucial aspect of the design process for centrifugal impellers is the establishment of specific blade shapes. A rapid inviscid flow analysis procedure was developed for incorporation within a geometry manipulation code. Using a single streamtube model, a single-pass computation technique was generated. A two-zone model ensures that key features of the passage flow physics are incorporated. Several examples of industrial design problems are employed to demonstrate the capabilities of the rapid loading method and its use in a geometry design procedure (used by some 20 industrial design groups worldwide). Comparisons with a quasi-three-dimensional method are included. The rapid loading method is most accurate when the meridional stream paths have similar shapes to those for the hub and shroud contours. The technique is useful within a geometry generation program since rapid aerodynamic screening of candidate configurations is allowed with sufficient accuracy to avoid the need for quasi-three-dimensional approaches. If required, the final design may be analyzed using three-dimensional viscous flow calculation methods.


1996 ◽  
Vol 118 (2) ◽  
pp. 385-393 ◽  
Author(s):  
M. Zangeneh

A three-dimensional inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modeled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and nonuniform inlet flow diffusers is found to be most significant from 50 percent chord to the trailing edge region. The flows through both diffusers are computed by using Denton’s three-dimensional inviscid Euler solver and Dawes’ three-dimensional Navier–Stokes solver under sheared in-flow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.


2011 ◽  
Vol 94-96 ◽  
pp. 1476-1480
Author(s):  
Cai Hua Wang

Centrifugal compressors are power machineries used widely. Fully understanding of the complex three-dimensional flow field is very important to design higher pressure ratio, higher efficiency centrifugal compressor. In this paper, time marching method is adopted to solve the three-dimensional viscous N-S equations under the relative coordinate system. The internal flow field of the “full controllable vortex” high speed centrifugal impeller is analyzed and the medial velocity vector distribution and the development of the velocity of each section in the impeller are showed. From the figures, it can be seen that the “wake” phenomenon, such as Ecckart described, caused by the curvature, Coriolis force and the boundary layer is exist


Author(s):  
Ali Reza Mazaheri ◽  
Homayoon Emdad ◽  
Goodarz Ahmadi

Three dimensional unsteady inviscid flows in convergent-divergent nozzles is of importance in understanding the stability of rockets and jet propulsion. A computer program for evaluating unsteady inviscid flow conditions in three-dimensional eccentric as well as concentric nozzles is developed. The program uses the cell-centered finite-volume method based on Roe’s approximate Riemann solver scheme. The flow simulation results in concentric circular nozzles are compared with the one-dimensional analytic solutions and the accuracy of the computation model is verified. The results for steady and unsteady flows through eccentric and concentric convergent-divergent nozzles are then presented. A range of exit to throat areas, pressure ratios, and inlet Mach number are considered.


1968 ◽  
Vol 90 (3) ◽  
pp. 258-264 ◽  
Author(s):  
M. Ribaut

An analysis is presented which applies to the flow through a three-dimensional cascade of arbitrary shape using potential theory. It is shown that without simplifying assumptions a calculation method can be developed, which avoids numerical calculation of derivatives and leads for incompressible and inviscid flow to a system of linear equations. The different possibilities for the boundary vortex vector are discussed and the most suitable form for the components of velocity derived.


2000 ◽  
Author(s):  
Tarek Mekhail ◽  
Du Zhao Hui ◽  
Chen Han Ping ◽  
Willem Janson

Abstract The flow inside a centrifugal impeller has various complex three dimensional phenomena (flow separation, jet-wake structure, shock wave, etc.). In this study, the internal flow field calculation of Samsung, high pressure ratio, high speed, centrifugal impeller with splitter blades is obtained by commercially available CFX-Tascflow code with CFX-Turbogrid for grid generation. The results are compared to that obtained previously by Denton and Dawes codes. The impeller is used in the first stage centrifugal compressor of an industrial gas turbine. The CFX-Tascflow results showed some differences Mach number contours. Also, the calculations are performed for Krain’s backswept impeller and the results are compared to the experimental measurements. Simulation of tip clearance has been done and the results were in a good agreement with the previous experiments.


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