Calculations of Three-Dimensional, Viscous Flow and Wake Development in a Centrifugal Impeller

1981 ◽  
Vol 103 (2) ◽  
pp. 367-372 ◽  
Author(s):  
J. Moore ◽  
J. G. Moore
Keyword(s):  
Viscous Flow ◽  
Pressure Field ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Calculation Procedure ◽  
Wake Flow ◽  
Centrifugal Impeller ◽  
Duct Flow ◽  
Reduced Pressure ◽  
Flow Calculation

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.

A Calculation Procedure for Three-Dimensional, Viscous, Compressible Duct Flow. Part II—Stagnation Pressure Losses in a Rectangular Elbow

1979 ◽  
Vol 101 (4) ◽  
pp. 423-428 ◽  
Author(s):  
John Moore ◽  
Joan G. Moore
Keyword(s):  
Three Dimensional ◽  
Inviscid Flow ◽  
Stagnation Pressure ◽  
Calculation Procedure ◽  
Duct Flow ◽  
Pressure Losses ◽  
Pressure Distributions ◽  
Starting Point ◽  
Flow Part ◽  
Good Agreement

Three-dimensional, turbulent flow is calculated in an elbow used by Stanitz for an experimental investigation of secondary flow. Calculated wall-static pressure distributions and distributions of stagnation-pressure loss, both spatial and as a function of mass-flow ratio, are in good agreement with Stanitz’ measurements, justifying the use of a relatively simple mixing-length viscosity model. The calculation procedure and the results of two-dimensional “inviscid” flow calculations used as the starting point for the present calculations are described in Part I of this paper. The computed flow field shows clearly the development of the passage vortices.

Computation of Viscous Flow Around Propeller-Body Configurations: Series 60 CB = 0.6 Ship Model

1994 ◽  
Vol 38 (02) ◽  
pp. 137-157 ◽  
Author(s):  
F. Stern ◽  
H. T. Kim ◽  
D. H. Zhang ◽  
Y. Toda ◽  
J. Kerwin ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Turbulence Modeling ◽  
Critical Evaluation ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Ship Model ◽  
Flow Method ◽  
Critical Issues ◽  
Three Dimensional Configuration ◽  
Extensive Experimental Data

Validation of a viscous-flow method for predicting propeller-hull interaction is provided through detailed comparisons with recent extensive experimental data for the practical three-dimensional configuration of the Series 60 CB = 0.6 ship model. Modifications are made to the k-e turbulence model for the present geometry and application. Agreement is demonstrated between the calculations and global and some detailed aspects of the data; however, very detailed resolution of the flow is lacking. This supports the previous conclusion for propeller-shaft configurations and axisymmetric bodies that the present procedures can accurately simulate the steady part of the combined propeller-hull flow field, although turbulence modeling and detailed numerical treatments are critical issues. The present application enables a more critical evaluation through further discussion of these and other relevant issues, such as the use of radial-and angular-varying body-force distributions, the relative importance of turbulence modeling and grid density on the resolution of the harmonics of the propeller inflow, and three-dimensional propeller-hull interaction, including the differences for the nominal and effective inflows and for the resulting steady and unsteady propeller performance. Also, comparisons are made with an inviscid-flow method. Lastly, some concluding remarks are made concerning the limitations of the method, requirements and prognosis for improvements, and application to the design of wake-adapted propellers.

scholarly journals Computation of the Jet-Wake Flow Structure in a Low Speed Centrifugal Impeller

1988 ◽  
Author(s):  
B. L. Lapworth ◽  
R. L. Elder
Keyword(s):  
Three Dimensional ◽  
Simple Algorithm ◽  
Design Flow ◽  
Wake Flow ◽  
Staggered Grid ◽  
Centrifugal Impeller ◽  
Low Speed ◽  
Flow Equations ◽  
System A ◽  
Speed Flow

The low speed flow through the shrouded de-Havilland Ghost centrifugal impeller is computed using an incompressible elliptic calculation procedure. The three dimensional viscous flow equations are solved using the SIMPLE algorithm in an arbitrary generalised coordinate system. A non-staggered grid arrangement is implemented in which pressure oscillations are eliminated using an amended pressure correction scheme. Flow computations are performed at ‘nominal’ low speed design and above design flow rates, and (on the coarse grids used in the calculations) good agreement is obtained with the experimentally observed jet-wake structure of the flow.

Application of Viscous Flow Computations for the Aerodynamic Performance of a Backswept Impeller at Various Operating Conditions

1988 ◽  
Vol 110 (3) ◽  
pp. 303-311 ◽  
Author(s):  
C. Hah ◽  
A. C. Bryans ◽  
Z. Moussa ◽  
M. E. Tomsho
Keyword(s):  
Experimental Data ◽  
Viscous Flow ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Centrifugal Impeller ◽  
Flow Phenomena ◽  
Overall Performance ◽  
Real Flow ◽  
Operating Points

Three-dimensional flowfields in a centrifugal impeller with backswept discharge at various operating points have been numerically investigated with a three-dimensional viscous flow code. Numerical results and experimental data were compared for the detailed flowfields and overall performance of the impeller at three operating conditions (optimum efficiency, choke, and near-surge conditions). The comparisons indicate that for engineering applications the numerical solution accurately predicts various complex real flow phenomena. The overall aerodynamic performance of the impeller is also well predicted at design and off-design conditions.

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

1980 ◽  
Vol 102 (3) ◽  
pp. 728-737 ◽  
Author(s):  
D. Adler
Keyword(s):  
Three Dimensional ◽  
Internal Flow ◽  
Inviscid Flow ◽  
Centrifugal Impeller ◽  
Future Research ◽  
Prediction Methods ◽  
Inviscid Flows ◽  
Recent Developments ◽  
Simplifying Assumptions ◽  
Internal Aerodynamics

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.

scholarly journals A Rapid Aerodynamic Loading Procedure for Centrifugal Impeller Design

1994 ◽  
Author(s):  
J. H. G. Howard ◽  
Colin Osborne ◽  
David Japikse
Keyword(s):  
Industrial Design ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Design Procedure ◽  
Inviscid Flow ◽  
Centrifugal Impeller ◽  
Zone Model ◽  
Geometry Design ◽  
Loading Method ◽  
Rapid Loading

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.

The Calculation of Three Dimensional Viscous Flow Through Multistage Turbomachines

1990 ◽  
Author(s):  
J. D. Denton
Keyword(s):  
Boundary Conditions ◽  
Unsteady Flow ◽  
Viscous Flow ◽  
Calculation Method ◽  
Three Dimensional ◽  
Mixing Process ◽  
Three Dimensional Flow ◽  
Flow Calculation ◽  
Dimensional Flow ◽  
Flow Through

The extension of a well established three dimensional flow calculation method to calculate the flow through multiple turbomachinery blade rows is described in this paper. To avoid calculating the unsteady flow, which is inherent in any machine containing both rotating and stationary blade rows, a mixing process is modelled at a calculating station between adjacent blade rows. The effects of this mixing on the flow within the blade rows may be minimised by using extrapolated boundary conditions at the mixing plane.

The Development of Wake Flow in a Centrifugal Impeller

1980 ◽  
Vol 102 (2) ◽  
pp. 382-389 ◽  
Author(s):  
M. W. Johnson ◽  
J. Moore
Keyword(s):  
Three Dimensional ◽  
Suction Side ◽  
Secondary Flows ◽  
Wake Flow ◽  
Centrifugal Impeller ◽  
Three Dimensional Flow ◽  
Cross Sectional ◽  
Flow Measurements ◽  
Compressor Impeller ◽  
Rotating Impeller

Three-dimensional flow, leading to the formation and the growth of a wake in a centrifugal impeller, has been studied. Results of flow measurements in a 1 m dia, shrouded, centrifugal compressor impeller running at 500 rpm are presented. Relative velocities and rotary stagnation pressures (p* = p + 1/2ρW2 − 1/2ρω2r2) were measured, on five cross-sectional planes between the inlet and outlet of the impeller, using pressure probes which were traversed within the rotating impeller passage. Particular attention was given to the convection of low p* fluid by secondary flows and to the formation of the wake in the shroud/suction-side corner region of the passage.

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