vol.22 (2009)

Bulletin of Research Center for Computing and Multimedia Studies
Vol.22, 2009 ISSN 1882-7594

Evaporation in Argon-Krypton Mixture by Constant Volume Molecular Dynamics Simulation
Yosuke Kataoka, Yuri Yamada
Received: July 14, 2008    PDF    Abstract
Evaporation in Argon-Krypton mixture is observed by constant volume molecular dynamics simulation. The molecular interaction potential energy is Lennard-Jones function. The initial configuration has the liquid part and the gas part which is empty. The thermodynamic properties, the pair-correlation functions and the self-diffusion coefficients are obtained at temperature T = 110 K, N = 7776 and the mole fraction of Argon is 0.5. The cpu time is counted as a function of the cut off distance.
On Estimation for Stress in Element of Rigid Bodies-Spring Model
Norio Takeuchi, Yasuyuki Tajiri, Kazuto Yamamura
Received: February 26, 2009    PDF    Abstract
The rigid-bodies spring model (RBSM) is a generalized model for discrete limit analysis, and assumes a rigid displacement field. For this reason, it cannot find the value of stress in each element. On the other hand, authors developed the Hybrid-type Penalty Method (HPM) which assumes the linear displacement field using the principle of hybrid type virtual work. In this paper, we proposed the method of finding for the stress in each element in RBSM by applying a rigid displacement field to the displacement field of this HPM, and examined the accuracy of the solution obtained from some examples of numerical computation by present method.
On Evacuation Simulation of Pupils from Schoolhouse
Mika Tanaka, Norio Takeuchi
Received: February 26, 2009    PDF    Abstract
In this paper, we considered the influence of the route at the time of pupils taking refuge from a schoolhouse with the simulation. We assumed the elementary school whose number of juvenile teachers is 372 persons as a simulation model. The number of schoolhouses is three stories high and four classrooms are on each floor. The life chute is set as one place of the third floor. We obtained the following results with this simulation. (1) A design of arrangement of a hallway etc. can evacuate pupils successfully. (2) The effect of life chute is not expectable without suitable guidance.
Melting of Diamond by Molecular Dynamics Simulation
Ryota Suemitsu, Yosuke Kataoka
Received: February 26, 2009    PDF    Abstract
The melting of the diamond is observed under high pressure by molecular dynamics simulation. The Tersoff potential is famous as the intermolecular potential function for classic molecular simulation. The melting of the diamond crystal is studied by the heating process. The obtained melting point is higher than the experimental result. Moreover, the accuracy of calculation of the Tersoff Potential is shown by a comparison of the calculated elastic constant with the experimental one.
Isotherm of Argon by Molecular Dynamics Simulation and Van der Waals Theory
Chizuko Itou, Yosuke Kataoka
Received: March 4, 2009    PDF    Abstract
We investigated pressure and internal energy when the density of Argon was changed by molecular dynamics simulation. We used application program “Materials Explorer 4.0” for present simulation. The molecular interaction potential energy is Lennard-Jones function. The isothermal of the result was compared with theoretical formula and examined the effectiveness of theoretical formula.
The Comparison of Compressibility Factor of Fluid Argon and Water Near the Critical Point
Keita Tanaka and Yosuke Kataoka
Received: March 4, 2009    PDF    Abstract
The pressures of fluid argon and water were calculated by molecular dynamics simulation. We used application program “Materials Explorer 5.0” for present simulation. The molecular interaction potential energy is Lennard-Jones function for argon. The SPCE model is assumed for fluid water. Their compressibility factor Z is plotted against the reduced pressure at three temperatures Tr = 1.05, 1.00 and 0.95. The effect of the hydrogen bond is observed.
Rapid Cooling in Gaseous Ar with High Density by Molecular Dynamics Simulation
Tsutomu Komiya, Yosuke Kataoka
Received: March 5, 2009    PDF    Abstract
Gaseous Ar with high density is cooled rapidly by molecular dynamics simulation. The potential function is Lennard-Jones 12-6 potential. The ensemble is NTV in the simulation. The structure of the cooled sample is classified as cluster or gaseous state by average potential energy, the pair correlation function and the coordination number. The obtained structure depends on the density and the temperature of the sample. The temperature dependence of the energy is also examined.
Environmentally Friendly Design of Hydraulic Systems
-Numerical Analysis of Flow in Bubble Eliminator-

Yutaka Tanaka, Ryushi Suzuki, Kohichi Nagaishi
Received: March 5, 2009    PDF    Abstract
Air entrainment in working fluids has greatly detrimental effects on function and lifetime of the fluid power components and systems. It is important to eliminate the air bubbles from the working oil to preserve oil quality, system performance, and to avoid possible damage of the components. A newly device using swirl flow for bubble elimination capable of eliminating bubbles and of decreasing dissolve gases has been developed. We focus on the technical issue for the shape of bubble eliminator from numerical analysis of flow in bubble eliminator.
Physical Properties in Copper-Nickel Mixture by Molecular Dynamics Simulation
Satomi Kiuchi, Yosuke Kataoka
Received: March 6, 2009    PDF    Abstract
Phase transition in copper-nickel mixture is observed by NTP molecular dynamics simulation. The molecular interaction potential energy is GEAM function. The nickel is added 10% to the copper 100% so that the total number of atoms in the basic cell is 108. The calculation is performed on the 11 kinds of compositions. The internal energy, the coordination number and the pair-correlation functions are obtained to see the phase transition.
A study on wave transmitting boundary by optimization method
Shinobu Furuya, Nagayuki Yoshida
Received: March 6, 2009    PDF    Abstract
When analyzing the wave propagation problem in the infinite or semi-infinite elastic body, the numerical device which can transmit the outgoing waves should be attached to the boundary of the finite analytical region. For generation of wave transmitting boundary, the discrete models are installed at the boundary. In this research, we propose the method to optimize the coefficients of this discrete model by the genetic algorism and sensitivity analysis. To investigate the validity of the present method, we use one-dimensional and two-dimensional rod models, and two-dimensional ground models.
A Study on 3-Dimensional Dynamic Analysis of Open Branched Structure Model
Atsushi Watanabe, Nagayuki Yoshida
Received: March 6, 2009    PDF    Abstract
This research defines the structure that could be seen in the upper part of the trees and their roots, as the open branched structure. Its aim is to make clear the secret of the earthquake-resistance characteristics of trees from the viewpoint of the structural engineering, and also to find out the useful information for the future of architectural structures. Because of that we create the 3-dimensional mathematical model of trees based on the bibliographic search to other fields such as botany, and performed the dynamic analysis for the models. As a result, we show the basic evaluation for the ability of trees against the earthquake which might be obtained through their evolution.
Educational Support Software for Structural Mechanics by Program Language Java
Junpei Yasukawa, Tomohiro Sukegawa, Nagayuki Yoshida
Received: March 6, 2009    PDF    Abstract
In the field of structural mechanics, it is thought that “Dynamic intuition” plays a major role in solving problems. In order to assist the students to solve a lot of problems easily regardless of the place or the time, we developed the educational support software for the structural mechanics based on the interactive method which is much easier to students than previous software. This software is encoded by the programming language of Java.
Numerical Simulation of Failure Behavior of Al2O3 by Hypervelocity Impact of Small Particle
Yasuhiro Ogawa, Kazuyoshi Arai, Eiichi Sato, Sunao Hasegawa
Received: March 9, 2009    PDF    Abstract
Hypervelocity impact tests of aluminum oxide (Al2O3) at 1.0km/s or less km/s were conducted, and failure behaviors were examined for the purpose of obtaining the basic date for verifying the validity of a numerical simulation method. In addition, the numerical simulation results of the hypervelocity impact at more than 1.0km/s were compared with impact tests results using two stage light gas gun.
Substituent Effects on the Gas Phase Stabilities of Benzylic Anions
Kazuhide Nakata, Mizue Fujio, Kichisuke Nishimoto, Yuho Tsuno
Received: March 13, 2009    PDF    Abstract
Relative gas phase stabilities of ring substituted benzylic anions were theoretically determined using proton transfer equilibria. Substituent effects of these benzylic anions were compared with one another to discuss what kind of electronic effects are important to determine the gas phase stabilities. According to statistical analyses, saturation effect was found to be influential in addition to inductive and resonance effects. The third term shuold be added to the conventional Yukawa-Tsuno equation in order to correlate the stabilities of benzylic anions.
Basic Research to Develop the Guideline of Landscape in Low-Impact City
-Targeted for Sotobori-

Kiyoe Miyashita,Tatsuya Hashiguchi, Jun Minamiguchi, Satoshi Kato, Satoshi Gido
Received: March 14, 2009    PDF    Abstract
In recent years, global warming is getting more seriously. In such situation, the buildings which bring in CO2 -reduction target is increasing. But, there is a concern that a lot of high-rise buildings are to be constructed in compensation for carbon dioxide reduction measures. On the other hand, high rise buildings have been controlled and the landscape begins to show a new look by the Ginza rule, as townscape regulations, beauty regulations have been executed. The purpose of this research is to develop the guideline of landscape in Sotobori, analyze and grasp a correlation between environment and landscape in low-impact city, in particular for around the Sotobori. As a result, it was found that there is a close correlation between environment and landscape. In addition, a need was pointed out for a guideline of Sotobori that has unique landscape with the buildings around it.
Vibrational property of bat of Fiber Reinforced Plastic
Kurosawa Akihisa, Iwahara Mitsuo, Nagamatsu Akio
Received: March 17, 2009    PDF    Abstract
Recently, the bat made of FRP(Fiber Reinforced Plastic) begins to be paid to attention. But there is a problem with a strong numbness. In this study, investigation into the cause was tried by modal analysis. First of all the excitation experiment was conducted in the bat and the modal parameters were compared. Next, the confirmation and the questionnaire of numbness were done by batting experiment. Finally, to modal analysis with good accuracy, the bat was examined by attenuation.
Modeling and vibration simulation of sporting goods
Moriyama Sachiko, Kurosawa Akihisa, Nagamatsu Akio, Iwahara Mitsuo
Received: March 17, 2009    PDF    Abstract
As for sporting goods, it is manufactured by the producer’s intuition and experience, and neither a concrete three dimension modeling nor the analysis are done. In this paper a concrete modeling was done in various sporting goods, the vibrational property was forecast, and it aimed at the agreement with experiment in this study. There are modeled for the metal baseball bat, the badminton racket, and the FRP bat.
Accuracy and improvement of Sound Simulation Program
Yukihiro Saitou, Daiki Taniguchi, Mitsuo Iwahara, Akio Nagamatsu
Received: March 19, 2009    PDF    Abstract
The sound simulation program forecasts the sound radiation. It was developed in this laboratory. A past research forecast the ball sound of the golf club. As for past research results, the difference was seen in “Sound collected by the excitation experiment” and “Sound that had been calculated by the sound simulation program” in the driver of the golf club. Therefore, the accuracy of the program is confirmed and improved in the present study. Then, it is preferable to be able to understand the accuracy of the program accurately. Therefore, the experiment and the calculation are conducted by using a plate that obtains a simple dynamic characteristic. And, “Accuracy of a basic calculation of the program” and “Influence of sound by diffraction” not considered by present program that thought to be related to the accuracy of the program. It compares from many fields, and the practicality of the program is examined