scholarly journals Numerical simulation of 2D granular particles and its analyses by means of the micropolar fluid model

Open Physics ◽  
2012 ◽  
Vol 10 (3) ◽  
Author(s):  
Kohei Takechi ◽  
Kyo Yoshida ◽  
Toshihico Arimitsu
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Micropolar Fluid ◽  
Fluid Model ◽  
Granular Flows ◽  
Coarse Graining ◽  
Two Dimensional ◽  
Vorticity Field ◽  
Spin Field ◽  
External Torque

AbstractNumerical simulations of two-dimensional granular flows under uniform mean shear and external body torque were performed following the setting of the authors’ previous study [10]. Convergence of the stresses with the increase of coarse-graining length is investigated. Difference R between vorticity field and spin field is controlled by the external torque and the stresses for the region R > 0 is obtained as well as those for R < 0. The symmetry of the stresses under the change of the sign of R is discussed.

Effects of Materials on Formation of Double-Layered Liners Shaped Charges

2009 ◽  
Vol 79-82 ◽  
pp. 1277-1280
Author(s):  
Yu Zheng ◽  
Xiao Ming Wang ◽  
Wen Bin Li ◽  
Wen Jin Yao
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Simulations ◽  
Double Layer ◽  
Two Dimensional ◽  
Materials Properties ◽  
X Ray ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Good Agreement

In order to study the effects of liner materials on the formation of Shaped Charges with Double Layer Liners (SCDLL) into tandem Explosively Formed Projectile (EFP), the formation mechanism of DLSCL was studied. Utilizing two-dimensional finite element dynamic code AUTODYN, the numerical simulations on the mechanical phenomenon of SCDLL forming into tandem EFP were carried out. X-ray pictures were obtained after Experiments on SCDLL. Comparisons between experimental results and numerical simulation results have good agreement. It can be concluded from the results that the materials properties and configurations of both liners are crucial to the formation of tandem EFP.

scholarly journals Numerical Simulation of Size Effects on Countercurrent Flow Limitation in PWR Hot Leg Models

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
I. Kinoshita ◽  
M. Murase ◽  
A. Tomiyama
Keyword(s):  
Numerical Simulation ◽  
Size Effect ◽  
Numerical Simulations ◽  
Size Effects ◽  
Fluid Model ◽  
Flow Channel ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Two Fluid Model ◽  
Two Fluid

We have previously done numerical simulations using the two-fluid model implemented in the CFD software FLUENT6.3.26 to investigate effects of shape of a flow channel and its size on CCFL (countercurrent flow limitation) characteristics in PWR hot leg models. We confirmed that CCFL characteristics in the hot leg could be well correlated with the Wallis parameters in the diameter range of0.05 m≤D≤0.75 m. In the present study, we did numerical simulations using the two-fluid model for the air-water tests withD=0.0254 m to determine why CCFL characteristics forD=0.0254 m were severer compared with those in the range,0.05 m≤D≤0.75 m. The predicted CCFL characteristics agreed with the data forD=0.0254 m and indicated that the CCFL difference betweenD=0.0254 m and0.05 mm≤D≤0.75 mm was caused by the size effect and not by other factors.

scholarly journals Simulation of Partially Filled Liquid in a Moving Tank

2020 ◽  
Vol 8 (6) ◽  
pp. 1941-1944
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Unsteady Flow ◽  
Numerical Simulations ◽  
Dynamic Pressure ◽  
Surface Displacement ◽  
Volume Of Fluid ◽  
Two Dimensional ◽  
Ansys Software ◽  
Free Surface Displacement

Numerical simulations have been carried out on a rectangular tank filled partially with liquid using volume of fluid technique. The tank has been given to and fro motion in one direction. Numerical simulation has been carried for a two dimensional case having laminar and unsteady flow. The changes in free surface displacement and dynamic pressure at different times has been observed using ANSYS software. The study was conducted for two sec. It was observed that free surface displacement of fluid increases with velocity. Also, with an increase in volume of liquid the sloshing effect decreases.

Effect of Prandtl Number in Turbulent Buoyant Jet Simulation

2013 ◽  
Vol 631-632 ◽  
pp. 1001-1005
Author(s):  
Shao Bo Wang ◽  
Shen Guang Fang ◽  
Li Qin Cui
Keyword(s):  
Numerical Simulation ◽  
Prandtl Number ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Numerical Results ◽  
Two Dimensional ◽  
Turbulent Prandtl Number ◽  
Buoyant Jet ◽  
Reasonable Range ◽  
Axial Concentration

Turbulent Prandtl number used in numerical simulation has effect on exact prediction of velocity and heat transferring with two dimensional buoyant mathematical models. Various Prandtl number values advised by experiments are used to study its effect on numerical results approaching to real ones with model under axisymmetric coordinate. It shows that axial velocities can’t be affected by using various values of of Prandtl number in numerical simulations and can be predicted well. However, it affects the exact prediction of axial concentration to extent, and a smaller value of Prandtl number tends to forecast a smaller axial concentration than real one, and vice versa. A reasonable range of turbulent Prandtl number for various Reynold numbers was suggested.

scholarly journals Numerical Technique for Sloshing Velocity in a Partially Filled Moving Tank

2020 ◽  
Vol 8 (6) ◽  
pp. 3046-3049
Keyword(s):  
Numerical Simulation ◽  
Laminar Flow ◽  
Numerical Simulations ◽  
Numerical Technique ◽  
Volume Of Fluid ◽  
Dimensional Case ◽  
Two Dimensional ◽  
Volume Of Fluid Method ◽  
Ansys Software ◽  
Time Period

Numerical simulations have been carried out on a partially filled rectangular tank using volume of fluid method. The tank has been given to and fro motion. Numerical simulation has been carried for a two dimensional case having laminar flow. The effect of sloshing on velocity at different times has been observed using ANSYS software. The study was conducted for two sec. Variations in the velocity has been observed with the time period.

scholarly journals Numerical simulation of two-dimensional steady granular flows in rotating drum: On surface flow rheology

2005 ◽  
Vol 17 (10) ◽  
pp. 103303 ◽  
Author(s):  
M. Renouf ◽  
D. Bonamy ◽  
F. Dubois ◽  
P. Alart
Keyword(s):  
Numerical Simulation ◽  
Granular Flows ◽  
Surface Flow ◽  
Two Dimensional ◽  
Rotating Drum

On the Use of Two-Dimensional Incompressible Flow to Study Secondary Eyewall Formation in Tropical Cyclones

2010 ◽  
Vol 67 (12) ◽  
pp. 3765-3773 ◽  
Author(s):  
Yumin Moon ◽  
David S. Nolan ◽  
Mohamed Iskandarani
Keyword(s):  
Tropical Cyclone ◽  
Numerical Simulations ◽  
Tropical Cyclones ◽  
Incompressible Flow ◽  
Two Dimensional ◽  
Vorticity Field ◽  
The Core ◽  
Secondary Eyewall Formation ◽  
Two Dimensional Flow ◽  
Order Of Magnitude

Abstract Previous studies have offered hypotheses for the mechanisms that lead to secondary eyewall formation in tropical cyclones by using two-dimensional incompressible flow. Those studies represented the convection-induced vorticity field as either large but weak vortices that are the same sign as the tropical cyclone core or as purely asymmetric vorticity perturbations that are an order of magnitude weaker than the core. However, both observations and full-physics simulations of tropical cyclones indicate that the convection-induced vorticity field should also include clusters of small vorticity dipoles whose magnitude is comparable to that of the high-vorticity core. Results of numerical simulations indicate that the interaction between the tropical cyclone core vortex and the convection-induced small vorticity dipoles of considerable strength in two-dimensional flow does not lead to coherent concentric vorticity ring formation. The axisymmetrization process under the simplification of two-dimensional incompressible flow appears to be incomplete for describing secondary eyewall formation.

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