APPLICATION OF A NEW HAMILTONIAN OF INTERACTION TO THREE-DIMENSIONAL STRUCTURES

2004 ◽  
Vol 18 (09) ◽  
pp. 1351-1368
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Experimental Data ◽  
Cohesive Energy ◽  
Noble Gases ◽  
Three Dimensional ◽  
The Other ◽  
Ionic Crystals ◽  
Coupling Constant ◽  
Good Agreement

Using a new Hamiltonian of interaction we have calculated the cohesive energy in three-dimensional structures. We have found the news dependences of this energy on the distance between the atoms. The obtained results are in a good agreement with experimental data in ionic, covalent and noble gases crystals. The coupling constant γ between the interacting field and the atoms is somewhat smaller than unity in ionic crystals and is some larger than unity in covalent and noble gases crystals. The formulae found by us are general and may be applied, also, to the other types of interactions, for example, gravitational interactions.

A HAMILTONIAN FOR THE BOSON–BOSON INTERACTION BASED ON ELASTIC COUPLING THROUGH FLUX LINES

2009 ◽  
Vol 23 (10) ◽  
pp. 1263-1272 ◽  
Author(s):  
VOICU DOLOCAN ◽  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN
Keyword(s):  
Experimental Data ◽  
Cohesive Energy ◽  
Noble Gases ◽  
Elastic Coupling ◽  
Flux Lines ◽  
Good Agreement

We present a Hamiltonian for the boson–boson interaction, based on elastic coupling through flux lines. This Hamiltonian may be used to study polaritons and plasmons and likewise the cohesive energy in crystals of noble gases. The presented results for crystals of noble gases are in a good agreement with experimental data.

Berechnung der 19F- und 195 Pt-NMR-Verschiebungen von FIuoro-Chloro-Bromo-Platinaten(IV) / Calculation of 19F and 195Pt NMR Shifts of Fluoro-Chloro-Brom o-Platinates(IV )

1997 ◽  
Vol 52 (4) ◽  
pp. 435-442 ◽  
Author(s):  
H.-H. Drews ◽  
W. Preetz
Keyword(s):  
Experimental Data ◽  
Chemical Shifts ◽  
Coupling Constant ◽  
Lower Field ◽  
Trans Influence ◽  
Nmr Signals ◽  
Increments Of Chemical Shifts ◽  
Good Agreement

By reaction of [PtBr4]2- with XeF2 in dichloromethane product mixtures containing nine fluoro-chloro-, four fluoro-bromo- and 15 fluoro-chloro-bromo-platinates(IV) are formed. All complexes are detectable by in situ l9F NMR measurements. Due to the increasing trans influence F < Cl < Br, the signals <5(19F) of symmetric F-Pt-F axes observed at highest field are shifted downfield on the average by 93 ppm as compared with δ(19F•) of F••Pt-Cl′ axes, and further to lower field by 40 ppm for <5(F••) of F••-Pt-Br″ axes. For the same reason the coupling constant 1J(F••Pt) ≈ 1099 Hz is by 13.3 % smaller than 1J(F•Pt) ≈ 1268 Hz, which is by 32.3 % smaller than δ(FPt) ≈ 1873 Hz. Based on the axis method, and taking into account characteristic increments of chemical shifts depending on cis influences, the calculation of the 195Pt NMR signals of 27 observed species of the system [PtFnCl6-n-mBrm]2- n, m = 0 - 6, has been successful. The 195Pt NMR shifts of further 29 so far not detected complexes are predicted. Using parameters depending on the geometry of the complex, the 19F NMR shifts of 28 F-containing platinates(IV) have been calculated in good agreement with the experimental data. 19F resonances are predicted for 19 so far missing complexes.

scholarly journals Design and analysis of flow rectifier of gas turbine flowmeter

2013 ◽  
Vol 17 (5) ◽  
pp. 1504-1507 ◽  
Author(s):  
Zhi-Fei Li ◽  
Zheng Du ◽  
Kai Zhang ◽  
Dong-Sheng Li ◽  
Zhong-Di Su ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Computational Model ◽  
Pressure Distribution ◽  
Gas Turbine ◽  
Turbulence Model ◽  
Pressure Loss ◽  
Three Dimensional ◽  
Turbine Flowmeter ◽  
Good Agreement

Three-dimensional computational model for a gas turbine flowmeter is proposed, and the finite volume based SIMPLEC method and k-? turbulence model are used to obtain the detailed information of flow field in turbine flowmeter, such as velocity and pressure distribution. Comparison between numerical results and experimental data reveals a good agreement. A rectifier with little pressure loss is optimally designed and validated numerically and experimentally.

A COMPARISON BETWEEN THE TWO-DIMENSIONAL AND THREE-DIMENSIONAL LATTICES

2004 ◽  
Vol 18 (25) ◽  
pp. 1301-1309 ◽  
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Lattice Constant ◽  
Cohesive Energy ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Two Dimensional ◽  
Coupling Constant ◽  
Dimensional Lattice ◽  
Analytical Formulae ◽  
Three Dimensional Space

By using a new Hamiltonian of interaction we have calculated the interaction energy for two-dimensional and three-dimensional lattices. We present also, approximate analytical formulae and the analytical formulae for the constant of the elastic force. The obtained results show that in the three-dimensional space, the two-dimensional lattice has the lattice constant and the cohesive energy which are smaller than that of the three-dimensional lattice. For appropriate values of the coupling constants, the two-dimensional lattice in a two-dimensional space has both the lattice constant and the cohesive energy, larger than that of the two-dimensional lattice in a three-dimensional space; this means that if there is a two-dimensional space in the Universe, this should be thinner than the three-dimensional space, while the interaction forces should be stronger. On the other hand, if the coupling constant in the two-dimensional lattice in the two-dimensional space is close to zero, the cohesive energy should be comparable with the cohesive energy from three-dimensional space but this two-dimensional space does not emit but absorbs radiation.

Particle Based Numerical Analysis of Green Water on FPSO Deck

2013 ◽  
Author(s):  
Cezar Augusto Bellezi ◽  
Liang-Yee Cheng ◽  
Kazuo Nishimoto
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Sea Water ◽  
Three Dimensional ◽  
High Amplitude ◽  
Green Water ◽  
Scale Models ◽  
Three Dimensional Models ◽  
Reduced Scale ◽  
Good Agreement

The green water phenomenon is boarding of sea water onto the deck due to high amplitude waves, which can cause several damages to the equipment on deck. In the present paper the green water phenomenon on three-dimensional models is analyzed using the Moving Particles Semi-Implicit Method (MPS), a fully lagrangian method for incompressible flow. This work is focused on the validation of the method comparing the numerical results with experimental results for green water on reduced scale models. The pressure on sensors over the deck of the models shows good agreement with experimental data.

scholarly journals Weak Localization Effect in Superconductors

1998 ◽  
Vol 12 (19) ◽  
pp. 763-773 ◽  
Author(s):  
Yong-Jihn Kim ◽  
K. J. Chang
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Sheet Resistance ◽  
Three Dimensional ◽  
Weak Localization ◽  
Transition Temperatures ◽  
Universal Behavior ◽  
Localization Effect ◽  
Disordered Superconductors ◽  
Good Agreement

We investigate the effect of weak localization on the transition temperatures of superconductors using Anderson's time-reversed scattered-state pairs, and show that disorder weakens electron–phonon interactions. With solving the BCS T c -equation, the calculated values for T c are in good agreement with experimental data for various two- and three-dimensional disordered superconductors. We find that the critical sheet resistance for the suppression of superconductivity in thin films does not satisfy the universal behavior but depends on sample, in good agreement with experiments.

Design Methods of Volute Casings for Turbocharger Turbine Applications

1996 ◽  
Vol 210 (2) ◽  
pp. 149-156 ◽  
Author(s):  
H Chen
Keyword(s):  
Experimental Data ◽  
Potential Flow ◽  
Design Method ◽  
Three Dimensional ◽  
Design Methods ◽  
Two Dimensional ◽  
Aerodynamic Design ◽  
3D Design ◽  
Flow Equations ◽  
Good Agreement

This paper discusses aerodynamic design methods of volute casings used in turbocharger turbines. A quasi-three-dimensional (Q-3D) design method is proposed in which a group of extended two-dimensional potential flow equations and the streamline equation are numerically solved to obtain the geometry of spiral volutes. A tongue loss model, based on the turbulence wake theory, is also presented, and good agreement with experimental data is shown.

scholarly journals MODELING OF ELASTIC-PLASTIC DEFORMATION OF ELEMENTS OF SPATIAL STRUCTURES DURING PULSE INTERACTION WITH FLUID BASED ON THE GODUNOV'S METHOD OF INCREASED ACCURACY

2019 ◽  
Vol 81 (4) ◽  
pp. 488-499
Author(s):  
Wang Cheng ◽  
Yang Tonghui ◽  
Li Wan ◽  
Tao Li ◽  
M.H. Abuziarov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shock Waves ◽  
Elastoplastic Deformation ◽  
Three Dimensional ◽  
Numerical Results ◽  
Two Dimensional ◽  
Wave Processes ◽  
Detonation Products ◽  
Comparison Of The Results ◽  
Good Agreement

The spatial problem of internal explosive loading of an elastoplastic cylindrical container filled with water in Eulerian - Lagrangian variables using multigrid algorithms is considered. A defining system of three-dimensional equations of the dynamics of gas, fluid, and elastoplastic medium is presented. For numerical modeling, a modification of S.K. Godunov scheme of the increased accuracy for both detonation products and liquids, and elastoplastic container is used. At the moving contact boundaries “detonation products - liquid”, “liquid - deformable body”, the exact solution of the Riemann's problem is used. A time dependent model is used to describe the propagation of steady-state detonation wave through an explosive from an initiation region. In both cases, the initiation of detonation occurs at the center of the charge. Two problems have been solved: the first task for the aisymmetric position of the charge, the second for the charge shifted relative to the axis of symmetry. In the first task, the processes are two-dimensional axisymmetric in nature, in the second task, the processes are essentially three-dimensional. A comparison is made of the results of calculations of the first problem using a three-dimensional method with a solution using a previously developed two-dimensional axisymmetric method and experimental data. Good agreement is observed between the numerical results for the maximum velocities and circumferential strains obtained by various methods and experimental data. There is good agreement between the numerical results obtained by various methods and the known experimental data. Comparison of the results of solving the first and second problems shows a significant effect of the position of the charge on the wave processes in the liquid, the processes of loading the container and its elastoplastic deformation. The dynamic behavior of a gas bubble with detonation products is analyzed. A significant deviation of the bubble shape from the spherical one, caused by the action of shock waves reflected from the structure, is shown. Comparison of the results of solving the first and second problems showed a significant effect of the charge position on wave processes in a liquid, the processes of loading a container and its elastoplastic deformation. In particular, in the second problem, shock waves of higher amplitude are observed in the liquid when reflected from the walls of the container.

Numerical Simulation of Twin-Parachute Inflation Process for Aircraft Ejection Escape

2020 ◽  
Author(s):  
Liwu Wang ◽  
Mingzhang Tang ◽  
Sijun Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Model ◽  
Physical Models ◽  
The Other ◽  
Arbitrary Lagrangian Eulerian ◽  
Safe Distance ◽  
Structure Interaction ◽  
Parachute Inflation ◽  
Good Agreement

Abstract In order to study the safe distance between twin-parachute during their inflation process for fighter ejection escape, the fighter was equipped with two canopies and two seats, two types of parachute were used to numerically simulate their inflation process, respectively. One of them is C-9, the other a slot-parachute (S-P). Their physical models were built, then the meshes inside and around both parachutes were generated for fluid-structure interaction (FSI) simulation. The penalty function and the arbitrary Lagrangian-Eulerian (ALE) method were employed in the FSI simulation. To validate the numerical model for FSI simulation, at first the single parachute of the twin-parachute was used for the FSI simulation, the predicted inflation times for both types of parachute were compared with the experimental data. The computed results are in good agreement with experimental data. As a result, the inflation times were predicted with twin-parachute for both kinds of parachute. On the basis of the locations of ejected seats after the separation of seat and pilot, the initial locations and orientations of twin-parachute were also obtained. The numerical simulations for both kinds of parachute were performed by the FSI method, respectively. Our results illustrate that when the interval time for two seats ejected is greater than 0.25s, two pilots attached the twin-parachute are safe, and the twin-parachute would not interfere each other. Moreover, our results also indicate that the FSI simulation for twin-parachute inflation process is feasible for engineering applications and have a great potential for wide use.

Effect of Droplet Starting Conditions on the Spray Dispersion Resulting From a Swirl Cup Injector

2021 ◽  
Author(s):  
Niklas Bürkle ◽  
Simon Holz ◽  
Enrico Bärow ◽  
Rainer Koch ◽  
Hans-Jörg Bauer
Keyword(s):  
Experimental Data ◽  
Droplet Diameter ◽  
Three Dimensional ◽  
Fuel Injector ◽  
Viable Option ◽  
Lagrange Method ◽  
Precessing Vortex Core ◽  
Starting Conditions ◽  
Good Agreement ◽  
Modelling Approach

Abstract In this work a numerical investigation of the sensitivities of the spray dispersion to different droplet starting parameters in a realistic three-dimensional fuel injector geometry is presented. The simulations are carried out using an Euler-Lagrange method. An extended version of the primary atomization model PAMELA [1,2] is used to predict the droplet diameter and to set the droplet starting conditions. Spray characteristics are compared to experimental data [3]. Thereby, a strong influence of the initial droplet velocities, the recirculation zone, the precessing vortex core as well as the turbulence modelling approach on the spray dispersion was identified. Droplet starting conditions which provide good agreement to the experimental data are determined. The study demonstrates that the presented approach is a viable option to predict the spray dispersion in combustors. Moreover, valuable insights on necessary improvements for modeling primary atomization are given.

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