Three-dimensional symmetric vortex flow

AIAA Journal ◽  
1964 ◽  
Vol 2 (12) ◽  
pp. 2218-2220 ◽  
Author(s):  
AJIT KUMAR RAY
Keyword(s):  
Vortex Flow ◽  
Three Dimensional

Tip Leakage Flow Characteristics Downstream of an Axial Flow Fan

1996 ◽  
Author(s):  
P. Puddu
Keyword(s):  
Vortex Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Axial Flow ◽  
Tip Leakage Flow ◽  
Single Wire ◽  
Vortex System ◽  
Tip Leakage ◽  
Stress Components ◽  
Computer Controlled

The three-dimensional viscous flow characteristics and the complex vortex system downstream of the rotor of an industrial exial fan have been determined by an experimental investigation using hot-wire anemometer. Single-wire slanted and straight type probes have been rotated about the probe axis using a computer controlled stepper motor. Measurements have been taken at four planes behind the blade trailing edge. The results show the characteristics of the relative flow as velocity components, secondary flow and kinetic energy defect. Turbulence intensity and Reynolds stress components in the leakage vortex area are also presented. The evolution of the leakage vortex flow during the decay process has also been evaluated in terms of dimension, position and intensity.

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.

Pressure-Probe Interference in a Vortex Flow

1978 ◽  
Vol 5 (2) ◽  
pp. 106-110
Author(s):  
O.O. Mojola
Keyword(s):  
Vortex Flow ◽  
Static Pressure ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Flow Region ◽  
Pressure Probe ◽  
Pressure Data ◽  
Pressure Sensing ◽  
Recirculation Flow ◽  
Made In

This paper examines the sensitivity of vortex-flows to disturbances arising from the insertion of conventional pressure-sensing probes into the flows. With a wide variety of pitot-tubes, static-pressure probes, and transverse-cylinder yawmeters, measurements were made in the vortex (recirculation) flow region of a separated, three-dimensional, turbulent boundary layer upstream of a vertical wall. The measurements, which included both local and surface pressure data, have been analysed to reveal how the shape, size, and alignment of probes independently and collectively contribute to the probe interference.

Passive Vortex Micromixers Utilizing Hybrid Laminations

2008 ◽  
Author(s):  
Jyh-Jian Chen ◽  
Yu-Cheng Luo ◽  
Shin-Hau Su ◽  
Nai-Yu Jheng
Keyword(s):  
Mass Transfer ◽  
Theoretical Investigation ◽  
Vortex Flow ◽  
Three Dimensional ◽  
Taylor Number ◽  
Concentration Profiles ◽  
Mixing Index ◽  
Mixing Performance ◽  
Damping Effect ◽  
Square Prism

This theoretical investigation analyzed the three-dimensional momentum and mass transfer characteristics arising from the multiple inlets and single outlet in micro chamber which consists of a right square prism, an octagonal prism or a cylinder. The effects of various geometric parameters, inlet velocities, and the types of lamination on the mixing characteristics were investigated, and the results were presented in terms of flow fields, concentration profiles, and mixing index. Numerical results indicated that vortex flow and numbers of inlets dominate the mixing index. At larger Taylor number, more inertia caused the powerful vortex flow in the chamber, and the damping effect on diffusion was diminished, which then increased the mixing performance. Furthermore, passive micromixers utilizing hybrid laminations showed better mixing results than those with parallel laminations.

Hypersonic Viscous Shock Layer Calculation of Leeward Vortex-Induced Heat Transfer on a Sharp Cone at a High Angle of Attack

1977 ◽  
Vol 99 (2) ◽  
pp. 307-313 ◽  
Author(s):  
J. C. Adams
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Shock Layer ◽  
Vortex Flow ◽  
Local Heating ◽  
Three Dimensional ◽  
Leeward Side ◽  
Heating Rates ◽  
Viscous Shock Layer ◽  
Sharp Cone

An analysis technique applicable to the problem of leeward vortex-induced heat transfer on a sharp cone at high angles of incidence under hypersonic laminar flow conditions is presented. The analysis, a three-dimensional hypersonic viscous shock layer approach in conjunction with a numerical solution procedure, is shown to be both applicable and accurate based on comparisons of heat-transfer distributions, surface pressure distributions, and leeward meridian flow-field profile measurements taken in a hypersonic wind tunnel. Detailed calculations of the embedded vortex flow field on the leeward side of the cone are presented in such a manner as to clearly portray exactly how embedded vortex flow influences local heating rates.

Nonlinear interaction of oblique three-dimensional Tollmien-Schlichting waves and longitudinal vortices, in channel flows and boundary layers

1992 ◽  
Vol 436 (1898) ◽  
pp. 585-602 ◽  
Keyword(s):  
Boundary Layers ◽  
Channel Flow ◽  
Nonlinear Interaction ◽  
Vortex Flow ◽  
Blow Up ◽  
Three Dimensional ◽  
Channel Flows ◽  
Nonlinear Evolution Equations ◽  
Longitudinal Vortex ◽  
Tollmien Schlichting

The present theoretical article considers the nonlinear interaction of oblique three dimensional Tollmien-Schlichting waves and induced or input longitudinal vortex motion, mainly for channel flow at large Reynolds numbers. Both the waves and the vortices are controlled by viscous-inviscid balancing but their respective flow structures are rather different because of the different typical timescales involved. This leads to the vortex-wave interaction being governed by nonlinear evolution equations on the vortex timescale, even though the wave amplitudes are notably small. The analogue in boundary-layer transition, addressed in a previous paper, is also re-considered here. Computational and analytical properties of the interaction equations for both channel flows and boundary layers are investigated, along with certain connections with companion studies of other vortex-wave interactions in channel flow. The nonlinear interactions in channel flow are found to lead to finitetime blow-up in amplitudes or to sustained vortex flow at large scaled times, depending on the input conditions. In particular, increasing the input amplitudes of the vortex or the wave can readily provoke blow-up even in the linearly stable regime; whereas in the case of sustained vortex flow new physical effects come into play on slightly longer timescales. Again, a very interesting feature is that the blowup response is found to be confined to a small range of wave angles near 45° relative to the original flow direction.

Effect of divider wall-to-end wall distance on the vortical structures and heat transfer characteristics of two-pass channel using topological analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhiqi Zhao ◽  
Lei Luo ◽  
Dandan Qiu ◽  
Songtao Wang ◽  
Zhongqi Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Vortex Flow ◽  
Topological Analysis ◽  
Three Dimensional ◽  
Separated Flow ◽  
Heat Transfer Characteristics ◽  
Content Type ◽  
Serpentine Channel ◽  
Transfer Characteristics ◽  
End Wall

Purpose This study aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis and critical points principles of three-dimensional vortex flow. Design/methodology/approach This aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis as well as critical points principles of three-dimensional vortex flow. Findings The endwall heat transfer in the narrow spacing passage is significantly stronger than that in a wide spacing channel. As the gap clearance is kept at 0.87 times of the hydraulic diameter, the endwall heat transfer and thermal performance can be accordingly enhanced with low pressure drops, which is because a relatively strong concentrated impingement flow for the medium gap clearance helps to restrain the downstream fluid flow and enhance the shear effect of the secondary flow. Practical implications The numerical results can be applied in designing sharp turn of serpentine channel in heat exchangers, heat sinks, piping system, solar receiver and gas turbine blades. Originality/value The evolution mechanism of the vortices in the turning region under different gap clearance was analyzed, and thermal enhancement characteristics were predicted innovatively using topological analysis method.

Numerical Simulation of Taylor Vortex Flow by GDQ Method

2000 ◽  
Author(s):  
L. Wang ◽  
C. Shu ◽  
Y. T. Chew
Keyword(s):  
Vortex Flow ◽  
Stokes Equations ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Computational Effort ◽  
Numerical Results ◽  
Numerical Code ◽  
Taylor Vortex ◽  
Specific Flow ◽  
Taylor Vortex Flow

Abstract In this study, the GDQ method was used to simulate a specific flow regime, Taylor vortex flow, of the motion of fluids between two concentric cylinders with rotating inner cylinder and stationary outer cylinder. An approach combining the SIMPLE strategy and GDQ discretization based on non-staggered mesh was proposed to solve the time-dependent, three-dimensional incompressible Navier-Stokes equations in primitive variable form. The numerical solution obtained has the accuracy of second-order in temporal discretization and high-order in spatial discretization. Also, this numerical code may allow the direct numerical simulations for the various regimes of Couette-Taylor flow problem. The performance of this approach was studied through a test case of Taylor vortex flow. The reported numerical results were compared with those from others. For this approach, accurate numerical results can be obtained by using fewer grid points compared with low-order methods. As a consequence, the computational effort can be greatly reduced.

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