An Analytical Model for the Incompressible Flow in Short Vortex Chambers

1969 ◽  
Vol 91 (2) ◽  
pp. 264-272 ◽  
Author(s):  
D. N. Wormley
Keyword(s):  
Static Pressure ◽  
Axisymmetric Flow ◽  
Radial Pressure ◽  
Vortex Chamber ◽  
Core Flow ◽  
Integral Analysis ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
End Wall ◽  
Main Vortex

A momentum integral analysis is presented for the incompressible, steady, axisymmetric flow in a short vortex chamber of the type commonly used in vortex valves. The analysis is developed with the aid of flow visualization photographs and considers the interaction which occurs between the main vortex core flow and the viscous chamber end wall boundary layers. The radial pressure distributions predicted by the analysis compare favorably with measured end wall static pressure distributions.

Boundary Layer Effects in the Turbulent Spiral Vortex Flow of a Compressible Fluid

1968 ◽  
Vol 183 (1) ◽  
pp. 179-188 ◽  
Author(s):  
B. F. Scott
Keyword(s):  
Boundary Layer ◽  
Vortex Flow ◽  
Free Stream ◽  
Three Dimensional ◽  
Cross Flow ◽  
Radial Pressure ◽  
Vortex Chamber ◽  
Adiabatic Wall ◽  
Spiral Vortex ◽  
Momentum Integral

Because of the characteristically narrow impeller tip width in a proposed supersonic centrifugal compressor design, boundary layer effects in the vortex chamber are likely to be significant. The radial pressure gradient in the chambers sweeps retarded fluid towards the centre of curvature of the streamlines, thereby creating a ‘cross-flow’ in the boundary layer which is three-dimensional. Although the flow geometry has axial symmetry, the cross-flow is not independent of the streamwise flow. The momentum—integral method is adopted, together with assumptions concerning the velocity profiles; the energy equation is solved with the assumption of an adiabatic wall. Simultaneous solution of the free stream and boundary layer equations yields results emphasizing the critical dependence of the transverse deflection and growth of the boundary layer on the whirl component of the velocity. Separation cannot be predicted, but effects in the free stream can be estimated when the perturbations are small. Although the results are related to compressor performance, the method is generally applicable in situations where the idealizing assumption of spiral vortex flow is acceptable.

Turbulent Boundary Layer Flow on the End Wall of a Cylindrical Vortex Chamber

1975 ◽  
Vol 189 (1) ◽  
pp. 305-315 ◽  
Author(s):  
T. J. Kotas
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layers ◽  
Boundary Layer Flow ◽  
Three Dimensional ◽  
Vortex Chamber ◽  
Cylindrical Vortex ◽  
Layer Flow ◽  
Momentum Integral ◽  
End Wall

A presentation of some measurements of velocities in the turbulent boundary layer on the end wall of a vortex chamber. These show that the boundary layer flow is three-dimensional with large inward radial velocities. Consequently, most of the fluid entering the vortex chamber passes into the central region through the boundary layers on the end walls rather than the main space of the vortex chamber. A momentum integral solution is used to obtain an estimate of the radial flow through the end-wall boundary layers. A comparison of the theoretical curves with the experimental results gives support to the main assumptions used in the solutions.

APR+ Core Flow and Pressure Distributions Under the 4 Pump Unbalanced Flow Condition

2013 ◽  
Author(s):  
K. Kim ◽  
D. J. Euh ◽  
Y. J. Youn ◽  
I. C. Chu ◽  
H. S. Choi ◽  
...  
Keyword(s):  
Flow Condition ◽  
Static Pressure ◽  
Flow Path ◽  
Test Facility ◽  
Hydraulic Characteristics ◽  
Ensemble Averaging ◽  
Core Flow ◽  
Pressure Distributions ◽  
Fuel Assemblies ◽  
Reduced Scale

The core inlet flow rates and exit pressure distributions of an APR+ (Advanced Power Reactor Plus) reactor were evaluated experimentally in this study. The tests were performed in the ACOP (APR+ Core Flow & Pressure) test facility constructed with a linear reduced scale of 1/5 referring to the prototype plant. The major flow path inside the reactor vessel was designed with a preservation of a geometrically similar flow without hindering the dynamic similarity. The 257 core simulators with 771 pressure impulse lines were installed in the ACOP facility to measure the hydraulic characteristics at the inlet and outlet of the fuel assemblies. The pressure distributions along the major flow path were obtained by measuring the static pressure and differential pressures at 584 points. The hydraulic characteristics of the reactor flow under an unbalanced cold leg flow condition were investigated by using an ensemble averaging process of 5 independent tests. The details of these experiments and a data analysis were described in this paper.

The Use of Deswirl Nozzles to Reduce the Pressure Drop in a Rotating Cavity With a Radial Inflow

1991 ◽  
Vol 113 (1) ◽  
pp. 106-114 ◽  
Author(s):  
P. R. Farthing ◽  
J. W. Chew ◽  
J. M. Owen
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Outer Part ◽  
Radial Pressure ◽  
Angular Speed ◽  
Rotating Disks ◽  
Pressure Distributions ◽  
Rotating Cavity ◽  
Predicted Values ◽  
Momentum Integral

A combined theoretical and experimental study is described in which deswirl nozzles were used to reduce the radial pressure drop in a rotating cavity with a radial inflow of air. The nozzles, which were attached to the outer part of the cavity, were angled such that the angular speed of the air at inlet could be in the opposite direction to that of the cavity. Solutions of the momentum-integral equations were used to predict the resulting radial distributions of pressure throughout the cavity. Flow visualization was used to confirm the flow structure, and transducers attached to one of the rotating disks in the cavity were used to measure the radial pressure distributions. Results are presented for “swirl fractions” (that is, the ratio of the angular speed of the air leaving the nozzles to that of the cavity) in the range −0.4 to +0.9, and for 0.01 < |Cw| Reφ−0.8 < 0.5, where Cw and Reφ are the nondimensional flow rate and rotational Reynolds number, respectively. The measured pressures are in good agreement with the predicted values, and the pressure drop across the cavity can be significantly less than that associated with solid-body rotation. The flow rate produced by the pressure drop across the cavity is not unique: There are up to three possible values of flow rate for any given value of pressure drop.

Some Temperature and Pressure Measurements in Confined Vortex Fields

1961 ◽  
Vol 83 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Joseph M. Savino ◽  
Robert G. Ragsdale
Keyword(s):  
Vortex Flow ◽  
Static Pressure ◽  
Circular Cylinders ◽  
Significant Finding ◽  
Pressure Measurements ◽  
Pressure Distributions ◽  
Total Temperature ◽  
Temperature And Pressure ◽  
End Wall ◽  
The Relationship

Studies were conducted on vortex flow generated within two right circular cylinders by injecting air through longitudinal vanes forming the chamber. The length to diameter ratios were 0.107 and 0.50. Experimental end wall static pressure distributions, some total pressures, and total temperature data are presented. The most significant finding was the large radial variations in the total temperature; this is related to the Ranque-Hilsch effect. Also discussed is the relationship between the static wall pressures and the effective velocities in the vortex.

scholarly journals The Use of De-Swirl Nozzles to Reduce the Pressure Drop in a Rotating Cavity With a Radial Inflow

1989 ◽  
Author(s):  
P. R. Farthing ◽  
J. W. Chew ◽  
J. M. Owen
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Outer Part ◽  
Radial Pressure ◽  
Angular Speed ◽  
Pressure Distributions ◽  
Rotating Cavity ◽  
Predicted Values ◽  
Momentum Integral ◽  
Good Agreement

A combined theoretical and experimental study is described in which de-swirl nozzles were used to reduce the radial pressure drop in a rotating cavity with a radial inflow of air. The nozzles, which were attached to the outer part of the cavity, were angled such that the angular speed of the air at inlet could be in the opposite direction to that of the cavity. Solutions of the momentum-integral equations were used to predict the resulting radial distributions of pressure throughout the cavity. Flow visualization was used to confirm the flow structure, and transducers attached to one of the rotating discs in the cavity were used to measure the radial pressure distributions. Results are presented for ‘swirl fractions’ (that is, the ratio of the angular speed of the air leaving the nozzles to that of the cavity) in the range −0.4 to + 0.9, and for 0.01 < | CW | Reϕ−0.8 < 0.5, where CW and Reϕ, are the nondimensional flow rate and rotational Reynolds number, respectively. The measured pressures are in good agreement with the predicted values, and the pressure drop across the cavity can be significantly less than that associated with solid-body rotation. The flow rate produced by the pressure drop across the cavity is not unique: there are up to three possible values of flow rate for any given value of pressure drop.

Mean velocity and static pressure distributions of a circular jet

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 196-197
Author(s):  
M. T. Islam ◽  
M. A. T. Ali
Keyword(s):  
Static Pressure ◽  
Mean Velocity ◽  
Pressure Distributions

The Departure from Equilibrium of Turbulent Boundary Layers

1968 ◽  
Vol 19 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H. McDonald
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Kinetic Energy ◽  
Stress Distribution ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
State Examination

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.

Experimental and Computational Analyses of Pressure Differentials in Flexible Ducts With Different Bent Angles

2007 ◽  
Author(s):  
Ray R. Taghavi ◽  
Wonjin Jin ◽  
Mario A. Medina
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Complex Geometry ◽  
Analysis Data ◽  
Secondary Flows ◽  
Low Flow ◽  
Pressure Drops ◽  
Pressure Distributions ◽  
Geometrical Effects ◽  
Cfd Analyses

A set of experimental analyses was conducted to determine static pressure drops inside non-metallic flexible, spiral wire helix core ducts, with different bent angles. In addition, Computational Fluid Dynamics (CFD) solutions were performed and verified by comparing them to the experimental data. The CFD computations were carried out to produce more systematic pressure drop information through these complex-geometry ducts. The experimental setup was constructed according to ASHRAE Standard 120-1999. Five different bent angles (0, 30, 45, 60, and 90 degrees) were tested at relatively low flow rates (11 to 89 CFM). Also, two different bent radii and duct lengths were tested to study flexible duct geometrical effects on static pressure drops. FLUENT 6.2, using RANS based two equations - RNG k-ε model, was used for the CFD analyses. The experimental and CFD results showed that larger bent angles produced larger static pressure drops in the flexible ducts. CFD analysis data were found to be in relatively good agreement with the experimental results for all bent angle cases. However, the deviations became slightly larger at higher velocity regimes and at the longer test sections. Overall, static pressure drop for longer length cases were approximately 0.01in.H2O higher when compared to shorter cases because of the increase in resistance to the flow. Also, the CFD simulations captured more pronounced static pressure drops that were produced along the sharper turns. The stronger secondary flows, which resulted from higher and lower static pressure distributions in the outer and inner surfaces, respectively, contributed to these higher pressure drops.

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.

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