Potential Flow Through Cascades with Multiple Aerofoils per Period

2020 ◽  
pp. 213-239
Author(s):  
Peter Jonathan Baddoo
Keyword(s):  
Potential Flow ◽  
Flow Through

Two-Dimensional Flow With Standing Vortexes in Ducts and Diffusers

1960 ◽  
Vol 82 (4) ◽  
pp. 921-927 ◽  
Author(s):  
Friedrich O. Ringleb
Keyword(s):  
Wind Tunnel ◽  
Potential Flow ◽  
Separation Control ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Princeton University ◽  
Two Dimensional Flow ◽  
Flow Through ◽  
Trapping Devices

The conditions for the equilibrium of two vortexes in a two-dimensional flow through a duct or diffuser are derived. Potential-flow considerations and a few basic results from viscous-flow theory are used for the discussion of the role of cusps as separation control and trapping devices for standing vortexes. The investigations are applied to cusp diffusers especially with regard to the wind tunnel of the James Forrestal Research Center of Princeton University.

An Investigation Into the Performance of Two ISA Metering Nozzles of Finite and Zero Area Ratio

1965 ◽  
Vol 87 (2) ◽  
pp. 525-529 ◽  
Author(s):  
S. Soundranayagam
Keyword(s):  
Reynolds Number ◽  
Potential Flow ◽  
Discharge Coefficient ◽  
Flow Model ◽  
Reynolds Numbers ◽  
Area Ratio ◽  
Flow Through

The flow through two ISA nozzles of area ratio zero and 0.4 was investigated to determine the nature of the flow and its variation with Reynolds number. Separation occurs within the nozzle of zero area ratio, the size of the bubble increasing with decreasing Reynolds number. The predicted discharge coefficient based on a simplified flow model agrees with experiment for large Reynolds numbers. Upstream influences affect the performance of the nozzle of area ratio 0.4. The flows through the two nozzles are not comparable, and potential-flow results cannot be used to explain flow in venturis and nozzles in pipes. The discharge-coefficient curve for area ratio 0.4 shows a distinct hump when based on the head differential measured as for venturis, but no hump when based on the head differential across the corner taps.

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.

Forces on Staggered Airfoil Cascades in Unsteady In-Phase Motion

1981 ◽  
Vol 103 (2) ◽  
pp. 299-306
Author(s):  
H. Shoji ◽  
H. Ohashi ◽  
N. H. Kemp
Keyword(s):  
Velocity Field ◽  
Conformal Mapping ◽  
Potential Flow ◽  
Approximate Solutions ◽  
Kutta Condition ◽  
Harmonic Motion ◽  
Flow Through ◽  
Stagger Angle ◽  
Analytical Expressions ◽  
Phase Motion

We consider incompressible potential flow through a cascade of staggered thin airfoils in general, unsteady, in-phase motion. With the assumptions of the Kutta condition and linearized wakes, exact analytical expressions are derived for pressure distribution, lift, and moment, using conformal mapping applied to the velocity field. The results are then specialized to harmonic motion, and applied to plunging, pitching, and sinusoidal gusts. All the results are expressed in closed-form as quadratures, and reduce to the well-known relations for thin airfoil theory, as the solidity decreases to zero. They agree with the unstaggered results of Kemp and Ohashi when the stagger angle is zero. Typical numerical results are given in the figures. They should serve as a measure of the accuracy of numerical or approximate solutions, as well as representing in a simple way the effects of stagger and solidity on unsteady cascade aerodynamics.

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