Three-dimensional flow effects in a two-dimensional supersonic air intake

1986 ◽  
Vol 2 (6) ◽  
pp. 546-551 ◽  
Author(s):  
S. A. Fisher
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Air Intake ◽  
Flow Effects

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.

Cellular flow in a partially filled rotating drum: regular and chaotic advection

2017 ◽  
Vol 825 ◽  
pp. 631-650 ◽  
Author(s):  
Francesco Romanò ◽  
Arash Hajisharifi ◽  
Hendrik C. Kuhlmann
Keyword(s):  
Three Dimensional ◽  
Reynolds Numbers ◽  
Chaotic Advection ◽  
Two Dimensional ◽  
Rotating Drum ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Heteroclinic Connection ◽  
Two Dimensional Flow ◽  
Chaotic Streamlines

The topology of the incompressible steady three-dimensional flow in a partially filled cylindrical rotating drum, infinitely extended along its axis, is investigated numerically for a ratio of pool depth to radius of 0.2. In the limit of vanishing Froude and capillary numbers, the liquid–gas interface remains flat and the two-dimensional flow becomes unstable to steady three-dimensional convection cells. The Lagrangian transport in the cellular flow is organised by periodic spiralling-in and spiralling-out saddle foci, and by saddle limit cycles. Chaotic advection is caused by a breakup of a degenerate heteroclinic connection between the two saddle foci when the flow becomes three-dimensional. On increasing the Reynolds number, chaotic streamlines invade the cells from the cell boundary and from the interior along the broken heteroclinic connection. This trend is made evident by computing the Kolmogorov–Arnold–Moser tori for five supercritical Reynolds numbers.

Reconstruction of three-dimensional flow fields from two-dimensional data

2020 ◽  
Vol 407 ◽  
pp. 109239
Author(s):  
José Miguel Pérez ◽  
Soledad Le Clainche ◽  
José Manuel Vega
Keyword(s):  
Three Dimensional ◽  
Flow Fields ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow

Three-Dimensional Flow Effects on Convective Heat Transfer From a Window Covered by a Simple Plane Blind With No Top Covering

2006 ◽  
Author(s):  
Patrick H. Oosthuizen
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Approximate Model ◽  
Conductive Heat ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Flow Effects

Most studies of convective heat transfer in window-blind systems assume that the flow over the window-blind arrangement is two-dimensional. In some cases, however, three-dimensional flow effects can become important. The present study was undertaken to determine how significant such effects can be for the particular case of a window covered by a simple plane blind. Only convective heat transfer has been considered. The situation considered is only an approximate model of the real window-blind situation. The window is represented by a rectangular vertical isothermal wall section embedded in a large vertical adiabatic plane wall surface and exposed to a large surrounding "room" in which the temperature is lower than the window temperature. The plane blind is represented by a thin vertical wall having the same size as the "window" which offers no resistance to heat transfer across it and in which conductive heat transfer is negligible. The gaps between the blind and the window at the sides and at the top of the window-blind system are assumed to be open. The flow has been assumed to be laminar and it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces. The solution has been obtained by numerically solving the three-dimensional governing equations written in dimensionless form. The effects of the dimensionless governing variables on the window Nusselt number have been numerically examined.

Theoretical Aspects of Thrust Vector Control by Secondary Gas Injection in Rocket Nozzles

1968 ◽  
Vol 72 (686) ◽  
pp. 171-177 ◽  
Author(s):  
John H. Neilson ◽  
Alastair Gilchrist ◽  
Chee K. Lee
Keyword(s):  
Vector Control ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Side Force ◽  
Thrust Vector Control ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Thrust Vector ◽  
Secondary Injection

This work deals with theoretical aspects of thrust vector control in rocket nozzles by the injection of secondary gas into the supersonic region of the nozzle. The work is concerned mainly with two-dimensional flow, though some aspects of three-dimensional flow in axisymmetric nozzles are considered. The subject matter is divided into three parts. In Part I, the side force produced when a physical wedge is placed into the exit of a two-dimensional nozzle is considered. In Parts 2 and 3, the physical wedge is replaced by a wedge-shaped “dead water” region produced by the separation of the boundary layer upstream of a secondary injection port. The modifications which then have to be made to the theoretical relationships, given in Part 1, are enumerated. Theoretical relationships for side force, thrust augmentation and magnification parameter for two- and three-dimensional flow are given for secondary injection normal to the main nozzle axis. In addition, the advantages to be gained by secondary injection in an upstream direction are clearly illustrated. The theoretical results are compared with experimental work and a comparison is made with the theories of other workers.

Three-dimensional flow images by reconstruction from two-dimensional vector velocity maps

1995 ◽  
Vol 8 (6) ◽  
pp. 915-923 ◽  
Author(s):  
Laurence N. Bohs ◽  
Barry H. Friemel ◽  
Joseph Kisslo ◽  
Daniel T. Harfe ◽  
Kathryn R. Nightingale ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Vector ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Vector Velocity

Three-Dimensional Flow Calculations of the Stator in a Highly Loaded Transonic Fan

1998 ◽  
Vol 120 (1) ◽  
pp. 141-146 ◽  
Author(s):  
P. R. Emmerson
Keyword(s):  
Three Dimensional ◽  
Flow Visualisation ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Efficiency Condition ◽  
Flow Effects ◽  
High Level ◽  
Transonic Fan ◽  
Very High ◽  
Highly Loaded

A three-dimensional viscous solver has been used to model the flow in the stator of a highly loaded single-stage transonic fan. The fan has a very high level of aerodynamic loading at the hub, which results in a severe hub endwall stall. Prediction of the flow at the 100 percent speed, peak efficiency condition has been carried out and comparisons are made with experiment, including stator exit traverses and fixed blade surface pressure tappings and flow visualisation. Comparisons are also made with an analysis of the rotor and stator rows using the DERA S1–S2 method. The three-dimensional predictions show good qualitative agreement with measurements in all regions of the flow field. Quantitatively the flow away from the hub region agreed the best. The general trends of the severe hub endwall stall were predicted, although the shape and size did not match experiment exactly. The S1–S2 system was unable to predict the hub endwall stall, since it arises from fully three-dimensional flow effects.

Transient Growth of Three-Dimensional Vortex Perturbations During Near-Parallel Collision With a Circular Cylinder

2006 ◽  
Author(s):  
X. Liu ◽  
J. S. Marshall
Keyword(s):  
Circular Cylinder ◽  
Vortex Core ◽  
Computational Study ◽  
Three Dimensional ◽  
The Body ◽  
Transient Growth ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Flow Features

A computational study is reported that examines the transient growth of three-dimensional flow features for nominally parallel vortex-cylinder interaction problems. We consider a helical vortex with small-amplitude perturbations that is advected onto a circular cylinder whose axis is parallel to the nominal vortex axis. The study assesses the applicability of the two-dimensional flow assumption for parallel vortex-body interaction problems in which the body impinges on the vortex core. The computations are performed using an unstructured finite-volume method for an incompressible flow, with periodic boundary conditions along the cylinder axis. Growth of three-dimensional flow features is quantified by use of a proper-orthogonal decomposition of the Fourier-transformed velocity and vorticity fields in the cylinder azimuthal and axial directions. The interaction is examined for different axial wavelengths and amplitudes of the initial helical waves on the vortex core, and the results for cylinder force are compared to the two-dimensional results. The degree of perturbation amplification as the vortex approaches the cylinder is quantified and shown to be mostly dependent on the dominant axial wavenumber of the perturbation. The perturbation amplification is observed to be greatest for perturbations with axial wavelength of about 1.5 times the cylinder diameter.

A Theory for the Side Force produced in Two-Dimensional Nozzles by Secondary Gas Injection

1968 ◽  
Vol 72 (687) ◽  
pp. 267-274
Author(s):  
John H. Neilson ◽  
Alastair Gilchrist ◽  
Chee K. Lee
Keyword(s):  
Gas Injection ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Side Force ◽  
Dimensional Flow ◽  
Increase With Increase ◽  
Two Dimensional Flow ◽  
Secondary Port ◽  
Theoretical Side

Summary:This work is concerned with the side force produced in rocket nozzles by secondary gas injection. A new theory for determining the side force is presented for two-dimensional flow and this is considered to be an important step towards a theory applicable to three-dimensional flow. The proposed theory is based on a double wedge model for the separated region upstream of the secondary port. The principal feature of the model is that it accounts tor the fact that the angle of the shock wave, originating from the separated region, is observed to increase with increase in secondary mass flow rate. Theoretical side force results are shown to compare favourably with experimental results obtained using two-dimensional nozzles and a comparison is made between the proposed theory and the theories of other workers.

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