COMPUTER SIMULATION OF THE GAS MIXTURE MIXING PROCESS IN THE SIMULATOR OF SELF-RESCUER IN THE TRAINING COMPLEX

2019 ◽  
Author(s):  
Artem Obukhov
Keyword(s):  
Computer Simulation ◽  
Gas Mixture ◽  
Mixing Process

Separation of nitrogen dioxide from the gas mixture with nitrogen by use of ZIF materials; computer simulation studies

2019 ◽  
Vol 168 ◽  
pp. 246-252 ◽  
Author(s):  
T. Chokbunpiam ◽  
R. Chanajaree ◽  
J. Caro ◽  
W. Janke ◽  
T. Remsungnen ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Nitrogen Dioxide ◽  
Gas Mixture ◽  
Simulation Studies ◽  
Computer Simulation Studies

GPU-Based Simulation on Particle Mixing in a Tote Blender

2012 ◽  
Vol 549 ◽  
pp. 918-923 ◽  
Author(s):  
Xin Xin Ren ◽  
Li Jie Cui ◽  
Wei Ge
Keyword(s):  
Computer Simulation ◽  
Large Scale ◽  
Solid Particles ◽  
Mixing Process ◽  
Experiment Data ◽  
Mixing Rate ◽  
Reliable Tool ◽  
Operation Conditions ◽  
Particle Mixing ◽  
Good Agreement

The mixing of dry solid particles is extremely important for pharmaceutical and chemical industries. Computer simulation is a convenient way to study the microscopic mixing process. In this paper, a GPU-based DEM software is tested in large-scale simulation of a tote blender by comparing with experiment data from literature and then employed to study the effects of operation conditions on the mixing rate. The results are in good agreement with experiments, confirming that the GPU-based DEM software is an effective and reliable tool for the study of micro-dynamics in particles mixing.

scholarly journals Hydrodynamics of a reactor with updated structure of frame mixing device

2021 ◽  
pp. 7-14
Author(s):  
V.O. Zazymko ◽  
M.F. Kalinina ◽  
V.Y. Shibetsky ◽  
O.M. Nedbailo
Keyword(s):  
Computer Simulation ◽  
Fluid Flow ◽  
Comparative Analysis ◽  
Fluid Flows ◽  
3D Models ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Element Analysis ◽  
Standard Design ◽  
Hydrodynamic Situation

This article is devoted to computer simulation of the hydrodynamic situation in a reactor with a standard design and an upgraded design of a frame stirrer. A comparative analysis of the hydrodynamics of fluid flows occurring in the volume due to the use of classical and modernized design was performed. An upgraded design of a frame stirrer for homogenizing the medium in a reactor has been proposed. The aim of this work was to study the influence of the geometry of the stirrer blades and their location in space on the speed and direction of flows in the reactor. The basis for the new design of the mixing device was the standard design of the frame mixer with two horizontal jumpers. Installation of additional blades and their placement at a certain angle to the vertical and horizontal planes and relative to each other was considered as one of the methods of improving the design. For this work, the study was conducted in the universal software system of finite element analysis ANSYS. Computer simulation is used to analyze complex systems and processes based on a computer model. The simulation was performed to analyze the influence of the geometry of the mixing device on the speed and direction of fluid flow in the apparatus. To conduct the study, 3D-models of two different types of geometry of the mixing device were built, physicomechanical parameters of the environment in the reactor were set and on the basis of these data the mixing process in the apparatus was modeled. In this work, the influence of plate geometry and their location in space on hydrodynamics is investigated. The basis of the proposed design of the mixing device is the task of intensifying the mixing process by increasing the mixing efficiency along the height of the apparatus. A comparative analysis of the direction of fluid flow, its velocity and temperature change using a standard and upgraded design of the mixing device was performed. It was found that when installing additional plates that are located at an angle to the horizontal and vertical planes in the reactor there are additional axial and radial fluid flows, which improves homogeneity and increases the intensity of mixing.

Study on Mixing Process of Two Component Gases in a Vertical Fluid Layer: Effectiveness on One-Dimensional Natural Circulation

2012 ◽  
Author(s):  
Hiroki Mizuno ◽  
Tetsuaki Takeda ◽  
Shumpei Funatani
Keyword(s):  
Natural Convection ◽  
Molecular Diffusion ◽  
Fluid Layer ◽  
Natural Circulation ◽  
Stratified Fluid ◽  
Heated Wall ◽  
Gas Mixture ◽  
Mixing Process ◽  
Vertical Slot ◽  
Two Component

This study is to investigate an effect of natural convection or natural circulation on a transport process by molecular diffusion in a stratified fluid layer consisting of two component gases. There are many experiment and analysis regarding natural convection or natural circulation in the vertical slot. However, there are few studies on natural convection or circulation and molecular diffusion in the stratified fluid layer consisting of two component gases. It was confirmed that these phenomena appear when the depressurization accident occurs in the very high temperature reactor (VHTR). Therefore it is important to evaluate the transport and mixing processes during the depressurization accident of the VHTR. The experiment has been performed regarding the combined phenomena of molecular diffusion and natural convection or circulation in a two parallel vertical slots filled with two component gases. The vertical slot consists of the one side heated wall and the other side cooled wall. The other slot consists of the two cooled walls. The dimension of heated wall is 500mm×200mm and thickness is 3mm. The width of the slot is 20mm and the aspect ratio is 25. Combination of nitrogen(N2)/argon(Ar), neon(Ne)/argon(Ar), helium(He)/nitrogen(N2) and helum(He)/argon(N2) was used as the first step of the experiment of the two component gases. The density change of the gas mixture and the gas temperature distribution in the slots were obtained. The mixing process of the heavier gas from the bottom side of the slot filled with the lighter gas was discussed in this paper. The experimental results showed that the transport phenomena by the molecular diffusion were influenced by the localized natural convection or circulation of the gas mixture in the stratified fluid layer. From the experimental results, it was found that the mixing process by molecular diffusion was affected significantly by the natural convection or circulation induced by the slight temperature difference between both vertical walls.

scholarly journals Mix experiments using a two-dimensional convergent shock-tube

2003 ◽  
Vol 21 (3) ◽  
pp. 403-409 ◽  
Author(s):  
D.A. HOLDER ◽  
A.V. SMITH ◽  
C.J. BARTON ◽  
D.L. YOUNGS
Keyword(s):  
Shock Tube ◽  
Turbulent Mixing ◽  
Three Dimensional ◽  
Gas Mixture ◽  
Mixing Process ◽  
Dense Gas ◽  
Atomic Weapons ◽  
Air Void ◽  
Good Agreement ◽  
Three Dimensional Simulations

This article reports the first Richtmyer–Meshkov instability experiments using an improved version of the Atomic Weapons Establishment convergent shock tube. These investigate the shock-induced turbulent mixing across the interfaces of an air/dense gas/air region. Multipoint ignition of a detonatable gas mixture produces a cylindrically convergent shock that travels into a test cell containing the dense gas region. The mixing process is imaged with shadowgraphy. Sample results are presented from an unperturbed experiment and one with a notch perturbation imposed on one of the dense gas interfaces. The unperturbed experiment shows the mixing across the dense gas boundaries and the motion of the bulk dense gas region. Imposition of the notch perturbation produces a mushroom-shaped air void penetrating the dense gas region. Three-dimensional simulations performed using the AWE TURMOIL3D code are presented and compared with the sample experimental results. A very good agreement is demonstrated. Conducting these first turbulent mixing experiments has highlighted a number of areas for future development of the convergent shock-tube facility; these are also presented.

Study on Mixing Process of Two Component Gases in a Stable Stratified Fluid Layer: Effectiveness on Natural Convection

2013 ◽  
Author(s):  
Tetsuaki Takeda ◽  
Shumpei Funatani
Keyword(s):  
Natural Convection ◽  
Molecular Diffusion ◽  
Fluid Layer ◽  
Natural Circulation ◽  
Stratified Fluid ◽  
Heated Wall ◽  
Gas Mixture ◽  
Mixing Process ◽  
Vertical Slot ◽  
Two Component

This study is to investigate an effect of natural convection or natural circulation on a transport process by molecular diffusion in a stratified fluid layer consisting of two component gases. There are many experiment and analysis regarding natural convection or natural circulation in the vertical slot. However, there are few studies on natural convection or circulation and molecular diffusion in the stratified fluid layer consisting of two component gases. It was confirmed that these phenomena appear when the depressurization accident occurs in the very high temperature reactor (VHTR). Therefore it is important to evaluate the transport and mixing processes during the depressurization accident of the VHTR. The experiment has been performed regarding the combined phenomena of molecular diffusion and natural convection or circulation in a two parallel vertical slots filled with two component gases. The vertical slot consists of the one side heated wall and the other side cooled wall. The other slot consists of the two cooled walls. The dimension of heated wall is 500mm×200mm and thickness is 3mm. The width of the slot is 20mm and the aspect ratio is 25. Combination of nitrogen (N2)/argon(Ar), neon(Ne)/Ar, helium(He)/N2 and He/Ar was used as the first step of the experiment of the two component gases. The density change of the gas mixture and the gas temperature distribution in the slots were obtained. The mixing process of the heavier gas from the bottom side of the slot filled with the lighter gas was discussed in this paper. The experimental results showed that the transport phenomena by the molecular diffusion were influenced by the localized natural convection or circulation of the gas mixture in the stratified fluid layer. From the experimental results, it was found that the mixing process by molecular diffusion was affected significantly by the natural convection or circulation induced by the slight temperature difference between both vertical walls.

Characterization of Modulated Structure Through Structure Images and their Computer Simulation

1990 ◽  
Vol 48 (1) ◽  
pp. 70-71
Author(s):  
Kiyomichi Nakai ◽  
Yusuke Isobe ◽  
Chiken Kinoshita ◽  
Kazutoshi Shinohara
Keyword(s):  
Computer Simulation ◽  
High Resolution ◽  
Spherical Aberration ◽  
High Resolution Electron Microscopy ◽  
Basic Mechanism ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Transmitted Beam ◽  
Modulated Structure ◽  
Resolution Electron

Induced spinodal decomposition under electron irradiation in a Ni-Au alloy has been investigated with respect to its basic mechanism and confirmed to be caused by the relaxation of coherent strain associated with modulated structure. Modulation of white-dots on structure images of modulated structure due to high-resolution electron microscopy is reduced with irradiation. In this paper the atom arrangement of the modulated structure is confirmed with computer simulation on the structure images, and the relaxation of the coherent strain is concluded to be due to the reduction of phase-modulation.Structure images of three-dimensional modulated structure along <100> were taken with the JEM-4000EX high-resolution electron microscope at the HVEM Laboratory, Kyushu University. The transmitted beam and four 200 reflections with their satellites from the modulated structure in an fee Ni-30.0at%Au alloy under illumination of 400keV electrons were used for the structure images under a condition of the spherical aberration constant of the objective lens, Cs = 1mm, the divergence of the beam, α = 3 × 10-4 rad, underfocus, Δf ≃ -50nm and specimen thickness, t ≃ 15nm. The CIHRTEM code was used for the simulation of the structure image.

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