scholarly journals III. The theory of free stream lines

1890 ◽  
Vol 47 (286-291) ◽  
pp. 129-133
Keyword(s):  
Free Stream ◽  
Complex Variables ◽  
Two Dimensional ◽  
Limited Application ◽  
Stream Lines ◽  
General Method

The chief object of the paper is to give a general method for the problem of free stream lines in two-dimensional motion of liquids when the boundaries are plane. The method rests on the transformation from one diagram to another by means of functions of complex variables, and, so far, is similar to that given by Kirchhoff in his ‘Vorlesungen,’ which is, however, of very limited application. The first part is devoted to general theorems of transformation.

Two-dimensional incompressible fluid jet penetration

1967 ◽  
Vol 29 (2) ◽  
pp. 273-287 ◽  
Author(s):  
D. F. Hopkins ◽  
J. M. Robertson
Keyword(s):  
Free Stream ◽  
Density Ratio ◽  
Two Dimensional ◽  
Principal Characteristics ◽  
Yield Information ◽  
Jet Penetration ◽  
Stream Lines ◽  
Kinetics Of ◽  
Kinematic Solution ◽  
Flow Case

The principal characteristics of jet penetration are the appearance of free stream-lines at the sides of the jet and of a dividing streamline, which separates the jet and penetrated fluid. Kinematic analysis of such flow via free-streamline theory and the notched hodograph is developed with one unspecified parameter, the ratio of jet to counterstream velocity in the steady flow case. The kinetics of the problem, appearing when the jet and penetrated (or counterstream) fluid differ in density, is simply related to the kinematic solution via the square root of the density ratio. Experiments, both steady state and transient with several liquids, are presented which generally verify the theory. The experiments also yield information on the magnitude of the parameter and indicate its variation with the density ratio.

scholarly journals Relaxation methods applied to engineering problems XII. Fluid motions characterized by 'free' stream-lines

1946 ◽  
Vol 240 (815) ◽  
pp. 117-161 ◽  
Keyword(s):  
Conformal Transformation ◽  
Free Stream ◽  
Two Dimensional ◽  
Relaxation Methods ◽  
Inviscid Fluids ◽  
Engineering Problems ◽  
Steady Motions ◽  
Stream Lines ◽  
In Virtue Of ◽  
Hydrodynamical Theory

This paper deals with problems which are like the percolation problems of Part VII (Shaw & Southwell 1941) in that a double condition, imposed at a boundary initially unknown, replaces the more usual single condition at a specified boundary. They relate to ‘free’ stream-lines in the hydrodynamical theory of inviscid fluids. For plane two-dimensional (steady) motions, the device of conformal transformation has led in the hands of Helmholtz, Kirchhoff and Rayleigh to a variety of solutions; but up to the present it has not taken account of gravity, and it would not seem capable of extension to motions characterized by axial symmetry. Relaxation Methods, in virtue of their tentative approach, here deal successfully with some problems hitherto unsolved.

Two- and Three-Dimensional Simulations of the Flow Around a Cylinder Fitted With Strakes

2012 ◽  
Author(s):  
Bruno S. Carmo ◽  
Rafael S. Gioria ◽  
Ivan Korkischko ◽  
Cesar M. Freire ◽  
Julio R. Meneghini
Keyword(s):  
Reynolds Number ◽  
Vortex Shedding ◽  
Free Stream ◽  
Three Dimensional ◽  
The Body ◽  
Vortex Wake ◽  
Two Dimensional ◽  
Flow Around A Cylinder ◽  
Three Dimensional Simulations ◽  
Angle Of Rotation

Two- and three-dimensional simulations of the flow around straked cylinders are presented. For the two-dimensional simulations we used the Spectral/hp Element Method, and carried out simulations for five different angles of rotation of the cylinder with respect to the free stream. Fixed and elastically-mounted cylinders were tested, and the Reynolds number was kept constant and equal to 150. The results were compared to those obtained from the simulation of the flow around a bare cylinder under the same conditions. We observed that the two-dimensional strakes are not effective in suppressing the vibration of the cylinders, but also noticed that the responses were completely different even with a slight change in the angle of rotation of the body. The three-dimensional results showed that there are two mechanisms of suppression: the main one is the decrease in the vortex shedding correlation along the span, whilst a secondary one is the vortex wake formation farther downstream.

Nonlinear Aspects of Subcritical Shallow-Water Flow Past Two-Dimensional Obstructions

1978 ◽  
Vol 22 (04) ◽  
pp. 203-211
Author(s):  
Nils Salvesen ◽  
C. von Kerczek
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Flow Problem ◽  
Free Stream ◽  
The Body ◽  
Two Dimensional ◽  
Third Order ◽  
Submerged Body ◽  
The Mean ◽  
The Waves

Some nonlinear aspects of the two-dimensional problem of a submerged body moving with constant speed in otherwise undisturbed water of uniform depth are considered. It is shown that a theory of Benjamin which predicts a uniform rise of the free surface ahead of the body and the lowering of the mean level of the waves behind it agrees well with experimental data. The local steady-flow problem is solved by a numerical method which satisfies the exact free-surface conditions. Third-order perturbation formulas for the downstream free waves are also presented. It is found that in sufficiently shallow water, the wavelength increases with increasing disturbance strength for fixed values of the free-stream-Froude number. This is opposite to the deepwater case where the wavelength decreases with increasing disturbance strength.

scholarly journals V. On the theory of free stream lines

1890 ◽  
Vol 181 ◽  
pp. 389-431 ◽  
Keyword(s):  
Free Stream ◽  
Fluid Motion ◽  
Steady Motion ◽  
Two Dimensions ◽  
Mathematical Solution ◽  
The Subject ◽  
Negative Pressures ◽  
Stream Lines ◽  
Salient Edges

The attention of mathematicians was first called to the subject of the present paper by a memoir of Helmholtz’s in 1868, on “Discontinuous Fluid Motion.” In discussing the steady motion of liquids past salient edges of fixed obstacles, it is found that the assumptio of continuity of the motion leads to negative pressures in the liquid. Helmholtz showed, in the paper above-mentioned, that some cases of this kind could be solved by assuming a surface of discontinuity, on one side of which the liquid is at rest, and he gave a mathematical solution of one case where the motion is in two dimensions.

A General Method for Growing Two-Dimensional Crystals of Organic Semiconductors by “Solution Epitaxy”

2016 ◽  
Vol 55 (33) ◽  
pp. 9519-9523 ◽  
Author(s):  
Chunhui Xu ◽  
Ping He ◽  
Jie Liu ◽  
Ajuan Cui ◽  
Huanli Dong ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Two Dimensional ◽  
General Method

scholarly journals Restoration of superconductivity in high magnetic fields in UTe2

2020 ◽  
Vol 34 (32) ◽  
pp. 2030007
Author(s):  
Andrei G. Lebed
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Superconducting State ◽  
Critical Magnetic Field ◽  
High Magnetic Fields ◽  
Two Dimensional ◽  
Upper Critical Magnetic Field ◽  
Reentrant Superconductivity ◽  
Theoretical Results ◽  
General Method

It was theoretically predicted more than 20 years ago [A. G. Lebed and K. Yamaji, Phys. Rev. Lett. 80, 2697 (1998)], that a triplet quasi-two-dimensional (Q2D) superconductor could restore its superconducting state in parallel magnetic fields, which are higher than its upper critical magnetic field, [Formula: see text]. It is very likely that, recently, such phenomenon has been experimentally discovered in the Q2D superconductor UTe2 by Nicholas Butch, Sheng Ran, and their colleagues and has been confirmed by Japanese–French team. We review our previous theoretical results using such a general method that it describes the reentrant superconductivity in the abovementioned compound and will hopefully describes the similar phenomena, which can be discovered in other Q2D superconductors.

Optimal design for the free-stream water wheel: A two-dimensional study

Energy ◽  
2021 ◽  
Vol 214 ◽  
pp. 118880
Author(s):  
Olivier Cleynen ◽  
Sebastian Engel ◽  
Stefan Hoerner ◽  
Dominique Thévenin
Keyword(s):  
Optimal Design ◽  
Free Stream ◽  
Stream Water ◽  
Two Dimensional ◽  
Water Wheel
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