Closure to “Discussion of ‘Three-Dimensional Theory of Incompressible and Inviscid Flow Through Mixed Flow Turbomachines’” (1965, ASME J. Eng. Power, 87, pp. 372–373)

1965 ◽  
Vol 87 (4) ◽  
pp. 373-373
Author(s):  
M. J. Schilhansl
Keyword(s):  
Three Dimensional ◽  
Inviscid Flow ◽  
Dimensional Theory ◽  
Mixed Flow ◽  
Flow Through

Three-Dimensional Theory of Incompressible and Inviscid Flow Through Mixed Flow Turbomachines

1965 ◽  
Vol 87 (4) ◽  
pp. 361-372
Author(s):  
M. J. Schilhansl
Keyword(s):  
Radial Flow ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Two Dimensional ◽  
Surfaces Of Revolution ◽  
Dimensional Theory ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Flow Through ◽  
Flow Study

In this paper the author presents a three-dimensional flow study for mixed (axial and radial) flow rotors. In order to make the analysis manageable the actual stream surfaces are assumed to coincide with surfaces of revolution. The intersections of the blade surfaces with these surfaces of revolution are mapped onto planes normal to the axis of the rotor. The investigation of the flow in the “picture” planes is based on available two-dimensional cascade theories. Position and shape of the surfaces depend upon the equilibrium of the flow in the direction perpendicular to the surfaces of revolution. The flow in each individual surface of revolution is found by remapping from the planes. Improved position and shape of the surfaces of revolution can be derived from the equilibrium condition. This procedure must be iterated until two consecutive iterations lead to the same result.

The effects of trailing vorticity on the flow through highly loaded cascades

1976 ◽  
Vol 74 (4) ◽  
pp. 721-740 ◽  
Author(s):  
James E. Mccune ◽  
William R. Hawthorne
Keyword(s):  
Incompressible Flow ◽  
Design Problem ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Dimensional Theory ◽  
Blade Loading ◽  
Large Pressure ◽  
Flow Through ◽  
The Mean ◽  
Highly Loaded

This paper presents a procedure whereby three-dimensional inviscid flow through a highly loaded turbomachinery cascade of lifting lines can be treated by methods corresponding to classical aerodynamic theory. In contrast to earlier linearized (thin airfoil) three-dimensional theory, the present study allows analysis of the flow corresponding to the large turning and/or large pressure ratios induced by practical rotors or stators. For the sake of simplicity, the present paper is limited to incompressible flow through a highly loaded rectilinear cascade and to the design problem, i.e. given blade loading. Formulae are derived for both the mean and the three-dimensional components of the flow; in particular, the velocities at the blades induced by the trailing vorticity associated with nonuniform blade circulation are determined.

Improved κ-ɛ Modelling of Impeller Flow Performance of a Mixed-Flow Pump under off-Design Operating States

1993 ◽  
Vol 207 (4) ◽  
pp. 219-229 ◽  
Author(s):  
S M Fraser ◽  
Y Zhang
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Careful Analysis ◽  
Navier Stokes ◽  
Mean Flow ◽  
Mixed Flow ◽  
Navier Stokes Equations ◽  
Flow Through ◽  
The Mean ◽  
Flow Pump

Three-dimensional turbulent flow through the impeller passage of a model mixed-flow pump has been simulated by solving the Navier-Stokes equations with an improved κ-ɛ model. The standard κ-ɛ model was found to be unsatisfactory for solving the off-design impeller flow and a converged solution could not be obtained at 49 per cent design flowrate. After careful analysis, it was decided to modify the standard κ-ɛ model by including the extra rates of strain due to the acceleration of impeller rotation and geometrical curvature and removing the mathematical ill-posedness between the mean flow turbulence modelling and the logarithmic wall function.

Hydraulic Performance of a Mixed-Flow Pump: Unsteady Inviscid Computations and Loss Models

2001 ◽  
Vol 123 (2) ◽  
pp. 256-264 ◽  
Author(s):  
B. P. M. van Esch ◽  
N. P. Kruyt
Keyword(s):  
Potential Flow ◽  
Flow Model ◽  
Three Dimensional ◽  
Hydraulic Performance ◽  
Mixed Flow ◽  
Global Performance ◽  
Flow Through ◽  
Loss Models ◽  
Potential Flow Model ◽  
Flow Pump

The hydraulic performance of an industrial mixed-flow pump is analyzed using a three-dimensional potential flow model to compute the unsteady flow through the entire pump configuration. Subsequently, several additional models that use the potential flow results are employed to assess the losses. Computed head agrees well with experiments in the range 70 percent–130 percent BEP flow rate. Although the boundary layer displacement in the volute is substantial, its effect on global characteristics is negligible. Computations show that a truly unsteady analysis of the complete impeller and volute is necessary to compute even global performance characteristics; an analysis of an isolated impeller channel and volute with an averaging procedure at the interface is inadequate.

Experimental and Numerical Study of Three-Dimensional Flows in a Mixed-Flow Pump Stage

1994 ◽  
Author(s):  
T. Takemura ◽  
A. Goto
Keyword(s):  
Numerical Study ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Swirl Flow ◽  
Experimental Results ◽  
Test Fluid ◽  
Internal Flows ◽  
Mixed Flow ◽  
Pump Stage ◽  
Flow Through

Internal flows of a low specific speed pump stage, having a mixed-flow impeller and a vaned bowl diffuser combination, have been investigated experimentally and numerically. Air was used as the test fluid, and the internal flows were measured at various locations and under various capacities. Flow calculations were made, for both the isolated impeller case and the complete stage case, using Denton viscous codes LOSS3D and MULTSTAGE14, by which the three-dimensional steady flow through multiple blade rows can be calculated using the inter-row mixing process. Experimental results showed the effects of the interaction between the impeller and the reverse flow, originating in the downstream diffuser, even at the design point capacity. While an impeller exit reverse flow occurred at the shroud side in the isolated impeller calculation, it was observed at the hub side in the complete stage case, showing good agreement with the experimental results. Although the flow in the diffuser was highly distorted due to a strong swirl flow, patterns of total pressure distribution could be well predicted by the complete stage calculation.

An Analysis of Flow Through a Mixed Flow Impeller

1972 ◽  
Vol 94 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Yasutoshi Senoo ◽  
Yoshiyuki Nakase
Keyword(s):  
Finite Number ◽  
Flow Condition ◽  
Three Dimensional ◽  
Meridional Plane ◽  
Surfaces Of Revolution ◽  
Mixed Flow ◽  
Numerical Examples ◽  
Orthogonal Coordinate System ◽  
Plane Solution ◽  
Flow Through

In this report, a method of analyzing steady, three-dimensional, subsonic, nonviscous flow through a turbomachine with arbitrary hub and shroud shapes and with a finite number of blades is presented. In order to make the analysis manageable, the stream surfaces are assumed to be axisymmetric. Position and shape of these surfaces, which depend upon the work of blades, are obtained by a meridional plane solution using a quasi-orthogonal coordinate system. The flow condition on these surfaces of revolution and the work of blades are obtained by a new blade-to-blade solution and the results are used to improve the meridional plane solution. This procedure is repeated until solution converges. Some numerical examples are given.

Modelling of Incompressible Three-Dimensional Flow in Rotating Turbomachinery Passages

2002 ◽  
Author(s):  
C. Cravero ◽  
A. Satta ◽  
M. Marini
Keyword(s):  
Compressible Flows ◽  
Incompressible Flows ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Pump Impeller ◽  
Preconditioning Technique ◽  
Cfd Method ◽  
Flow Pump

A CFD method, previously developed by the authors for compressible flows, has been modified through a preconditioning technique to account for purely incompressible flows. Such a code is used to compute three-dimensional flows in a mixed flow pump impeller at design and off-design conditions. The results of the inviscid flow approach are critically discussed by comparison to available experimental data.

A Pseudo Three-Dimensional Analysis of Flows in Vaneless Diffusers for Mixed-Flow Compressors

1975 ◽  
Vol 17 (6) ◽  
pp. 348-356
Author(s):  
F. J. Wallace ◽  
R. Atkey ◽  
A. Whitfield
Keyword(s):  
Radial Flow ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Unstable Flow ◽  
Mixed Flow ◽  
Pressure Distributions ◽  
Suitable Combination ◽  
Vaneless Diffusers ◽  
Stable Flow

A solution is given of the equations of motion for inviscid flow with axial symmetry in mixed-flow diffusers of any given geometry. The associated computer programmes have been applied, together with similar programmes for the impeller based on streamline-normal solutions, to predict streamline, velocity and pressure distributions in a variety of vaneless diffusers as follows: (i) radial-flow impeller with radial diffuser; (ii) mixed-flow impeller with pure conical diffuser and (iii) mixed-flow impeller with curved diffusers. The first of these is shown to give essentially stable flow, the second extremely unstable flow and the third conditionally stable flow provided that a suitable combination of initial contraction and hub/shroud profile is adopted.

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