A Surface Vorticity Theory for Propeller Ducts and Turbofan Engine Cowls in Non-Axisymmetric Incompressible Flow

1978 ◽  
Vol 20 (4) ◽  
pp. 201-219 ◽  
Author(s):  
V. P. Hill
Keyword(s):  
Mathematical Model ◽  
Fourier Series ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Axisymmetric Body ◽  
Fredholm Integral Equations ◽  
Three Dimensional Flow ◽  
Turbofan Engine ◽  
Pressure Distributions ◽  
Theoretical Pressure

Starting from the basic Fredholm integral equations, a surface vorticity theory is developed for the prediction of annular aerofoil performance in three-dimensional flow. A mathematical model is proposed for the general case of the axisymmetric body in non-axisymmetric flow, using a Fourier series to represent circumferential variations in bound vorticity strength. Using the pure incidence case as an example, it is indicated how an economical solution of the flow may be arrived at by use of a digital computer. The theoretical pressure distributions obtained are compared with the results of wind-tunnel tests on an annular aerofoil model.

Three-dimensional flow in cavities

1963 ◽  
Vol 16 (4) ◽  
pp. 620-632 ◽  
Author(s):  
D. J. Maull ◽  
L. F. East
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Large Span ◽  
Dimensional Flow ◽  
Pressure Distributions ◽  
Oil Flow ◽  
Two Dimensional Flow

The flow inside rectangular and other cavities in a wall has been investigated at low subsonic velocities using oil flow and surface static-pressure distributions. Evidence has been found of regular three-dimensional flows in cavities with large span-to-chord ratios which would normally be considered to have two-dimensional flow near their centre-lines. The dependence of the steadiness of the flow upon the cavity's span as well as its chord and depth has also been observed.

Effect of Blade Curving on the Flow Field Structure in an Annular Turbine Cascade

1999 ◽  
Author(s):  
Yanping Song ◽  
Zhongqi Wang ◽  
Wencai Lu ◽  
Wenyuan Xu
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Field Structure ◽  
Turbine Cascade ◽  
Three Dimensional Flow ◽  
Surface Pressure Distribution ◽  
Pressure Distributions ◽  
Curved Blade ◽  
Turbine Cascades ◽  
Annular Cascade

In the present paper, two annular turbine cascades have been tested in order to investigate the effect of blade curving on the structure of the three-dimensional flow field. The blades in all two cascades have the same section and they are stacked on the trailing edge that is straight in the first and a circular arc in the second. Detailed cascade tests consisted of passage flow parameter traverses, blade and endwall surface pressure distribution, and flow visualization. The results show that the flow field is three dimensional in an annular cascade with different pressure distributions near two endwalls, whose direct effect is amplified through the creation of passage vortices of different scale and strength at hub and tip. Blade curving changes the pressure field completely, in axial, pitchwise and spanwise directions. The combined effect of 3-D characteristics and blade curving causes significant differences of flow field structure in curved blade.

Flow in a centrifugal spectrometer

1992 ◽  
Vol 238 ◽  
pp. 221-250 ◽  
Author(s):  
A. A. Dahlkild ◽  
G. Amberg ◽  
H. P. Greenspan
Keyword(s):  
Vertical Wall ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Shear Layers ◽  
Vertical Shear ◽  
Rotational Flow ◽  
Basic Process ◽  
Three Dimensional Flow ◽  
Exploratory Experiment ◽  
Flow Through

Rotational flow through narrow axial channels is considered in connection with a proposed technique to sort and separate particles according to sedimentation velocities. Nonlinear and linear axisymmetric flow through two channels connected by a slot in the vertical wall is studied numerically. A linearized formulation for the three-dimensional flow through a circumferentially blocked channel, with arbitrary positioning of the inlets and outlets, is examined analytically. Both approaches indicate that to have a sharp criteria for fractionation, the vertical shear layers on the channel walls must overlap. Otherwise, Coriolis effects, accompanying a strong azimuthal motion, make the sorting less precise. Results of an exploratory experiment with a simple two-stage machine demonstrate the feasibility of the basic process for simultaneous and continuous separation and fractionation.

Three-Dimensional Flow in an Axial Turbine: Part 1 — Aerodynamic Mechanisms

1990 ◽  
Author(s):  
David Joslyn ◽  
Robert Dring
Keyword(s):  
Flow Visualization ◽  
Temperature Profile ◽  
Three Dimensional ◽  
Surface Flow ◽  
Inlet Temperature ◽  
Three Dimensional Flow ◽  
Axial Turbine ◽  
Physical Mechanisms ◽  
Pressure Distributions ◽  
Flow Part

This paper presents an exhaustive experimental documentation of the three–dimensional nature of the flow in a one–and–one–half stage axial turbine. The intent was to examine the flow within, and downstream of, both the stator and rotor airfoil rows so as to delineate the dominant physical mechanisms. Part 1 of this paper presents the aerodynamic results including: (1) airfoil and endwall surface flow visualization, (2) fullspan airfoil pressure distributions, and (3) radial–circumferential distributions of the total and static pressures, and of the yaw and pitch angles in the flow. Part 2 of the paper presents results describing the mixing, or attenuation, of a simulated spanwise inlet temperature profile as it passed through the turbine. Although the flow in each airfoil row possessed a degree of three–dimensionality, that in the rotor was the strongest.

Simulation on Three-Dimensional Flow Field of Oxidation Ditch

2012 ◽  
Vol 516-517 ◽  
pp. 1001-1005
Author(s):  
Wei Wei ◽  
Dun Qiu Wang ◽  
Jian Wen Wei ◽  
Hong Tao Zhou
Keyword(s):  
Mathematical Model ◽  
Flow Field ◽  
Three Dimensional ◽  
Oxidation Ditch ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Fluent Software ◽  
Simulation Results

Using the Fluent software, the flow field of oxidation ditch was simulated by the three dimensional turbulence mathematical model. The velocities were analyzed and measured, and the simulation results showed acceptable prediction of the velocities in the oxidation ditch. The results also showed that velocity could reach more than 0.3m/s when 8 impellers worked, and MLSS in the whole ditch were almost uniform, therefore, the oxidation ditch runs well.

Simulation of Interference Characteristics of the Model Supporting Beams with Different Forms of Section in Wind Tunnel Test

2014 ◽  
Vol 1025-1026 ◽  
pp. 910-913
Author(s):  
Xing Jun Hu ◽  
Yue Xing Miao
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Three Dimensional Flow ◽  
Ansys Fluent ◽  
Correction Error ◽  
Dimensional Flow ◽  
Pressure Distributions

In order to study the effects of the supporting beams with different forms of section on the aerodynamic characteristics of car models. Model supporting beams with three different forms of section were designed based on standard MIRA model. The commercial CFD software - Ansys Fluent was used to simulate the three-dimensional flow field around the standard MIRA model installed with three different kinds of supporting beams. With comparisons between the drag coefficients, pressure distributions and velocity distributions around the wheels with the different supporting beams, the reasons for the differences in aerodynamics are analyzed and advices were given for helping choosing the supporting beam with minimal disturbance to reduce the correction error.

Three-Dimensional Flow in an Axial Turbine: Part 1—Aerodynamic Mechanisms

1992 ◽  
Vol 114 (1) ◽  
pp. 61-70 ◽  
Author(s):  
D. Joslyn ◽  
R. Dring
Keyword(s):  
Flow Visualization ◽  
Temperature Profile ◽  
Three Dimensional ◽  
Surface Flow ◽  
Inlet Temperature ◽  
Three Dimensional Flow ◽  
Axial Turbine ◽  
Physical Mechanisms ◽  
Pressure Distributions ◽  
Flow Part

This paper presents an exhaustive experimental documentation of the three-dimensional nature of the flow in a one-and-one-half stage axial turbine. The intent was to examine the flow within, and downstream of, both the stator and rotor airflow rows so as to delineate the dominant physical mechanisms. Part 1 of this paper presents the aerodynamic results including: (1) airflow and endwall surface flow visualization, (2) full-span airfoil pressure distributions, and (3) radial-circumferential distributions of the total and static pressures, and of the yaw and pitch angles in the flow. Part 2 of the paper presents results describing the mixing, or attenuation, of a simulated spanwise inlet temperature profile as it passed through the turbine. Although the flow in each airfoil row possessed a degree of three-dimensionality, that in the rotor was the strongest.

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