633 Numerical analysis to evaluate three-dimensional vortical structures from two-dimensional velocity field

2012 ◽  
Vol 2012.61 (0) ◽  
pp. _633-1_-_633-2_
Author(s):  
Toru YATSUCHI ◽  
Katsuyuki NAKAYAMA
Keyword(s):  
Numerical Analysis ◽  
Velocity Field ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Vortical Structures

Plane turbulent jets in a bounded fluid layer

1992 ◽  
Vol 241 ◽  
pp. 587-614 ◽  
Author(s):  
T. Dracos ◽  
M. Giger ◽  
G. H. Jirka
Keyword(s):  
Experimental Investigation ◽  
Cross Section ◽  
Fluid Layer ◽  
Three Dimensional ◽  
Turbulent Jets ◽  
Two Dimensional ◽  
Vortical Structures ◽  
Secondary Currents ◽  
Fluid Layers ◽  
Bounding Surfaces

An experimental investigation of plane turbulent jets in bounded fluid layers is presented. The development of the jet is regular up to a distance from the orifice of approximately twice the depth of the fluid layer. From there on to a distance of about ten times the depth, the flow is dominated by secondary currents. The velocity distribution over a cross-section of the jet becomes three-dimensional and the jet undergoes a constriction in the midplane and a widening near the bounding surfaces. Beyond a distance of approximately ten times the depth of the bounded fluid layer the secondary currents disappear and the jet starts to meander around its centreplane. Large vortical structures develop with axes perpendicular to the bounding surfaces of the fluid layer. With increasing distance the size of these structures increases by pairing. These features of the jet are associated with the development of quasi two-dimensional turbulence. It is shown that the secondary currents and the meandering do not significantly affect the spreading of the jet. The quasi-two-dimensional turbulence, however, developing in the meandering jet, significantly influences the mixing of entrained fluid.

REVIEW—Progress in Numerical Turbomachinery Analysis

1976 ◽  
Vol 98 (4) ◽  
pp. 592-606 ◽  
Author(s):  
David Japikse
Keyword(s):  
Numerical Analysis ◽  
Steady Flow ◽  
Transonic Flow ◽  
Three Dimensional ◽  
Flow Fields ◽  
Design Methods ◽  
Two Dimensional ◽  
Wide Spread ◽  
The Past ◽  
Turbomachinery Design

Progress achieved in numerical analysis during the past decade now permits the turbo-machinery designer to carry out a wide variety of inviscid, steady flow, two-dimensional calculations for compressible sybsonic and transonic flow fields, including some strongly diffusing flows. Three-dimensional (including viscosity) calculations are under development and should find wide spread use as analysis tools during the next decade. This review offers an introduction to recent advances in numerical turbomachinery design methods guided by the author’s design usage of several of the techniques reported.

A Transport Model for the Deterministic Stresses Associated With Turbomachinery Blade Row Interactions

2000 ◽  
Vol 122 (4) ◽  
pp. 593-603 ◽  
Author(s):  
Allan G. van de Wall ◽  
Jaikrishnan R. Kadambi ◽  
John J. Adamczyk
Keyword(s):  
Turbine Blade ◽  
Transport Model ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Two Dimensional ◽  
Mean Flow ◽  
Viscous Effects ◽  
Vortical Structures ◽  
Blade Row ◽  
The Mean

The unsteady process resulting from the interaction of upstream vortical structures with a downstream blade row in turbomachines can have a significant impact on the machine efficiency. The upstream vortical structures or disturbances are transported by the mean flow of the downstream blade row, redistributing the time-average unsteady kinetic energy (K) associated with the incoming disturbance. A transport model was developed to take this process into account in the computation of time-averaged multistage turbomachinery flows. The model was applied to compressor and turbine geometry. For compressors, the K associated with upstream two-dimensional wakes and three-dimensional tip clearance flows is reduced as a result of their interaction with a downstream blade row. This reduction results from inviscid effects as well as viscous effects and reduces the loss associated with the upstream disturbance. Any disturbance passing through a compressor blade row results in a smaller loss than if the disturbance was mixed-out prior to entering the blade row. For turbines, the K associated with upstream two-dimensional wakes and three-dimensional tip clearance flows are significantly amplified by inviscid effects as a result of the interaction with a downstream turbine blade row. Viscous effects act to reduce the amplification of the K by inviscid effects but result in a substantial loss. Two-dimensional wakes and three-dimensional tip clearance flows passing through a turbine blade row result in a larger loss than if these disturbances were mixed-out prior to entering the blade row. [S0889-504X(00)01804-3]

A Predictive Technique for Buckling Analysis of Thin Section Panels Due to Welding

1996 ◽  
Vol 12 (04) ◽  
pp. 269-275
Author(s):  
Panagiotis Michaleris ◽  
Andrew DeBiccari
Keyword(s):  
Numerical Analysis ◽  
Heat Input ◽  
Large Scale ◽  
Three Dimensional ◽  
Analytical Models ◽  
Two Dimensional ◽  
Critical Buckling Load ◽  
Analysis Technique ◽  
Panel Thickness ◽  
Buckling Distortion

This paper presents an efficient and effective numerical analysis technique for predicting welding-induced buckling. The technique combines three-dimensional structural analyses with two-dimensional welding simulations. Implementation of the technique can determine the appropriate welding conditions under which the design critical buckling load is not exceeded. Experimental results obtained from small-and large-scale mock-up panels are used to confirm the predictions of the analytical models, The paper concludes with a study of the effects of heat input (weld size), panel size, and panel thickness on buckling distortion.

Aerodynamics of new solar parametric troughs: Two dimensional and three dimensional single module numerical analysis

Solar Energy ◽  
2016 ◽  
Vol 135 ◽  
pp. 742-749 ◽  
Author(s):  
Juan Pablo Núnez Bootello ◽  
Monica Mier-Torrecilla ◽  
Manuel Doblaré ◽  
Manuel Silva Pérez
Keyword(s):  
Numerical Analysis ◽  
Three Dimensional ◽  
Two Dimensional

Three-Dimensional Flow of a Newtonian Liquid Through an Annular Space with Axially Varying Eccentricity

2005 ◽  
Vol 128 (2) ◽  
pp. 223-231 ◽  
Author(s):  
Eduarda P. F. de Pina ◽  
M. S. Carvalho
Keyword(s):  
Velocity Field ◽  
Cross Section ◽  
Drill Pipe ◽  
Three Dimensional ◽  
Complete Analysis ◽  
Correct Prediction ◽  
Two Dimensional ◽  
Annular Space ◽  
Drilling Mud ◽  
Frictional Pressure Drop

Flow in annular space occurs in drilling operation of oil and gas wells. The correct prediction of the flow of the drilling mud in the annular space between the well wall and the drill pipe is essential to determine the variation in the mud pressure within the wellbore, the frictional pressure drop, and the efficiency of the transport of the rock drill cuttings. A complete analysis of this situation is extremely complex: the inner cylinder is usually rotating, the wellbore wall will depart significantly from cylindrical, the drill pipe is eccentric, and the eccentricity varies along the well. A complete analysis of this situation would require the solution of the three-dimensional momentum equation and would be computationally expensive and complex. Models available in the literature to study this situation do consider the rotation of the inner cylinder and the non-Newtonian behavior of the drilling fluids, but assume the relative position of the inner with respect to the outer cylinders fixed, i.e., they neglect the variation of the eccentricity along the length of the well, and the flow is considered to be fully developed. This approximation leads to a two-dimensional model to determine the three components of the velocity field in a cross-section of the annulus. The model presented in this work takes into account the variation of the eccentricity along the well; a more appropriate description of the geometric configuration of directional wells. As a consequence, the velocity field varies along the well length and the resulting flow model is three-dimensional. Lubrication theory is used to simplify the governing equations into a two-dimensional differential equation that describes the pressure field. The results show the effect of the variation of the eccentricity on the friction factor, maximum and minimum axial velocity in each cross section, and the presence of azimuthal flow even when the inner cylinder is not rotating.

On steady Stokes flow in a trihedral rectangular corner

2003 ◽  
Vol 476 ◽  
pp. 159-177 ◽  
Author(s):  
A. M. GOMILKO ◽  
V. S. MALYUGA ◽  
V. V. MELESHKO
Keyword(s):  
Velocity Field ◽  
Stokes Flow ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Stagnation Line ◽  
Stagnation Points ◽  
Boundary Velocity ◽  
Different Types ◽  
Spiral Shape ◽  
Induced Flow

Motivated by the recent paper of Hills & Moffatt (2000), we investigate the Stokes flow in a trihedral corner formed by three mutually orthogonal planes, induced by a non-zero velocity distribution over one of the walls of the corner. It is shown that the local behaviour of the velocity field near the edges of the corner, where a discontinuity of the boundary velocity is assumed, coincides with the Goodier–Taylor solution for a two-dimensional wedge. Analysis of the streamline patterns confirms the existence of eddies near the stationary edge in the flow, induced either by uniform translation of one of the walls of the corner in the direction perpendicular to its bisectrix or by uniform rotation of a side about the vertex of the corner. These flows are shown to be quasi-two-dimensional. If the wall rotates about a centre displaced from the vertex, the induced flow is essentially three-dimensional. In the antisymmetric velocity field, a stagnation line appears composed of stagnation points of different types. Otherwise the three-dimensionality manifests itself in a non-closed spiral shape of the streamlines.

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