Comparison of two-dimensional and three-dimensional time-dependent Hartree-Fock forCa40+Ca40atElab=278MeV

1978 ◽  
Vol 18 (1) ◽  
pp. 573-575 ◽  
Author(s):  
H. Flocard ◽  
M. S. Weiss
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Two Dimensional ◽  
Hartree Fock

Upstream motions in stratified flow

1988 ◽  
Vol 187 ◽  
pp. 487-506 ◽  
Author(s):  
I. P. Castro ◽  
W. H. Snyder
Keyword(s):  
Body Height ◽  
Three Dimensional ◽  
Time Dependent ◽  
Experimental Measurements ◽  
Two Dimensional ◽  
Towing Tank ◽  
First Order ◽  
Density Perturbations ◽  
Small Obstacle ◽  
Obstacle Height

In this paper experimental measurements of the time-dependent velocity and density perturbations upstream of obstacles towed through linearly stratified fluid are presented. Attention is concentrated on two-dimensional obstacles which generate turbulent separated wakes at Froude numbers, based on velocity and body height, of less than 0.5. The form of the upstream columnar modes is shown to be largely that of first-order unattenuating disturbances, which have little resemblance to the perturbations described by small-obstacle-height theories. For two-dimensional obstacles the disturbances are similar to those found by Wei, Kao & Pao (1975) and it is shown that provided a suitable obstacle drag coefficient is specified, the lowest-order modes (at least) are quantitatively consistent with the results of the Oseen inviscid model.Discussion of some results of similar measurements upstream of three-dimensional obstacles, the importance of towing tank endwalls and the relevance of the Foster & Saffman (1970) theory for the limit of zero Froude number is also included.

scholarly journals Josephson oscillations in split one-dimensional Bose gases

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Yuri Daniel van Nieuwkerk ◽  
Jörg Schmiedmayer ◽  
Fabian Essler
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Dimensional Theory ◽  
Bose Gases ◽  
Microscopic Description ◽  
One Dimensional ◽  
Hartree Fock ◽  
Equilibrium Dynamics ◽  
Self Consistent ◽  
Double Well Potential

We consider the non-equilibrium dynamics of a weakly interacting Bose gas tightly confined to a highly elongated double well potential. We use a self-consistent time-dependent Hartree--Fock approximation in combination with a projection of the full three-dimensional theory to several coupled one-dimensional channels. This allows us to model the time-dependent splitting and phase imprinting of a gas initially confined to a single quasi one-dimensional potential well and obtain a microscopic description of the ensuing damped Josephson oscillations.

COLLECTIVE-DYNAMICS EFFECTS IN FISSION OF 256,258FM ISOTOPES

2008 ◽  
Vol 17 (01) ◽  
pp. 81-88 ◽  
Author(s):  
A. DOBROWOLSKI ◽  
H. GOUTTE ◽  
J.-F. BERGER
Keyword(s):  
Generating Functions ◽  
Time Dependent ◽  
Two Dimensional ◽  
Generator Coordinate Method ◽  
Coordinate Method ◽  
Collective Dynamics ◽  
Hartree Fock ◽  
Mass Distributions ◽  
Generator Coordinate ◽  
Induced Fission

A dynamical approach to the neutron-induced fission of 255,257 Fm isotopes based on the time-dependent generator-coordinate method is applied. As the generating functions the eigensolutions of the constrained Hartree-Fock-Bogoliubov method with the effective D1S Gogny force are used. The here presented collective-dynamics calculations in the two-dimensional collective space described by quadrupole and octupole moments allow to determine the fragment mass distributions of those two Fm isotopes.

scholarly journals Two- and three-dimensional numerical simulations of the transition to oscillatory convection in low-Prandtl-number fluids

1998 ◽  
Vol 374 ◽  
pp. 145-171 ◽  
Author(s):  
DANIEL HENRY ◽  
MARC BUFFAT
Keyword(s):  
Prandtl Number ◽  
Relative Concentration ◽  
Three Dimensional ◽  
Power Spectra ◽  
Hadley Circulation ◽  
Time Dependent ◽  
Two Dimensional ◽  
General Behaviour ◽  
Shallow Cavities ◽  
Dependent Flow

The convective flows which arise in shallow cavities filled with low-Prandtl-number fluids when subjected to a horizontal temperature gradient are studied numerically with a finite element method. Attention is focused on a rigid cavity with dimensions 4×2×1, for which experimental data are available. The three-dimensional results indicate that, after a relative concentration of the initial Hadley circulation, a transition to time-dependent flows occurs in the form of a roll oscillation with a purely dynamical origin. This transition corresponds to a Hopf bifurcation with a breaking of symmetry that gives some specific properties to the time evolution of the flow: these properties are shown to be the result of the general behaviour of the dynamical systems. Calculations performed in the case of mercury compare well with the experiments with similar power spectra of the temperature, and this validates the analysis of the nature of the global flow performed in the limiting case Pr=0. All these results are discussed with respect to the linear and nonlinear analyses and to other computational experiments. Numerical results obtained in the corresponding two-dimensional situation give a different transition to the time-dependent flow: it is shown that in the three-dimensional cavity this type of two-dimensional transition is less probable than the observed transition with breaking of symmetry.

Comparisons of two- and three-dimensional time-dependent Hartree-Fock calculations of the reactionsO16+O16andCa40+Ca40

1978 ◽  
Vol 18 (6) ◽  
pp. 2631-2640 ◽  
Author(s):  
K. T. R. Davies ◽  
H. T. Feldmeier ◽  
H. Flocard ◽  
M. S. Weiss
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Hartree Fock

Time-based two dimensional modelling of NATM tunnelling

2002 ◽  
Vol 39 (3) ◽  
pp. 710-724 ◽  
Author(s):  
J H Shin ◽  
D M Potts
Keyword(s):  
Three Dimensional ◽  
Two Dimensions ◽  
Time Dependent ◽  
Soil Conditions ◽  
Measuring Instruments ◽  
Two Dimensional ◽  
Time Dependent Behaviour ◽  
Decomposed Granite ◽  
Granite Soil ◽  
Dependent Behaviour

A two dimensional model is commonly employed in practice for the analysis of tunnelling. Such analyses are computationally cheap and are useful for assessing the sensitivity of the problem to the construction method, studying the influence of varying soil conditions, and (or) finding appropriate locations for placing measuring instruments. However, simulating the three dimensional nature of tunnelling in two dimensions requires certain simplifications, including the use of empirical parameters to represent the construction sequence. In many cases the choice of parameter values are arbitrary and often not fully explained. In addition, the modelling methods are often only applicable for undrained or fully drained soil conditions where no time-dependent behaviour is involved during tunnel construction. In this paper an alternative two dimensional approach termed the "time-based modelling method" is proposed that can simulate both the three dimensional effects at the tunnel heading and the time-dependent behaviour during construction. It is proposed that the new approach is appropriate for the analysis of tunnelling in a relatively permeable soil and, as an example, the method is applied to the analysis of a new Austrian tunnelling method (NATM) tunnelling problem in decomposed granite soil. The results are compared with field data and excellent agreement is obtained.Key words: numerical modelling, time-dependent behaviour, NATM tunnelling, decomposed granite soil.

On the similarity of particle and photon tunneling and multiple internal reflections in one-dimensional, two-dimensional and three-dimensional photon tunneling

2014 ◽  
Vol 23 (06) ◽  
pp. 1460006 ◽  
Author(s):  
V. S. Olkhovsky
Keyword(s):  
Quantum Electrodynamics ◽  
Electromagnetic Waves ◽  
Relativistic Quantum ◽  
Three Dimensional ◽  
Time Dependent ◽  
Two Dimensional ◽  
Relativistic Quantum Field Theory ◽  
One Dimensional ◽  
Quantum Equation ◽  
Photon Tunneling

The formal mathematical analogy between time-dependent quantum equation for the nonrelativistic particles and time-dependent equation for the propagation of electromagnetic waves had been studied in [A. I. Akhiezer and V. B. Berestezki, Quantum Electrodynamics (FM, Moscow, 1959) [in Russian] and S. Schweber, An Introduction to Relativistic Quantum Field Theory, Chap. 5.3 (Row, Peterson & Co, Ill, 1961)]. Here, we deal with the time-dependent Schrödinger equation for nonrelativistic particles and with time-dependent Helmholtz equation for electromagnetic waves. Then, using this similarity, the tunneling and multiple internal reflections in one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) particle and photon tunneling are studied. Finally, some conclusions and future perspectives for further investigations are presented.

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