Verification and Validation of a Detonation Computational Fluid Dynamics Model

2016 ◽  
Vol 366 ◽  
pp. 40-46
Author(s):  
Rui Li Wang ◽  
Xiao Liang ◽  
Wen Zhou Lin ◽  
Xue Zhe Liu ◽  
Yun Long Yu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Verification And Validation ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Primary Means ◽  
Computational Fluid Dynamics Cfd ◽  
2D Space

Verification and validation (V&V) are the primary means to assess the accuracy and reliability in computational fluid dynamics (CFD) simulation. V&V of the multi-medium detonation CFD model is conducted by using our independently-developed software --- Lagrangian adaptive hydrodynamics code in the 2D space (LAD2D) as well as a large number of benchmark testing models. Specifically, the verification of computational model is based on the basic theory of the computational scheme and mathematical physics equations, and validation of the physical model is accomplished by comparing the numerical solution with the experimental data. Finally, some suggestions are given about V&V of the detonation CFD model.

Computational Fluid Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer Settler

2012 ◽  
Vol 57 (1) ◽  
pp. 173-178 ◽  
Author(s):  
M. Shabani ◽  
A. Mazahery
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Process Simulation ◽  
Chemical Process ◽  
Cfd Simulation ◽  
Complex Geometry ◽  
Physical Parameters ◽  
Cfd Model ◽  
Liquid Mixing ◽  
Computational Fluid Dynamics Cfd

Computational Fluid Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer Settler Mixer-settlers are widely used inmetallurgical, mineral and chemical process. One of the greatest challenges in the area of hydrometallurgy process simulation is agitation made by impeller inside mixer-settler which yet presents one of the most common operations. Computational fluid dynamics (CFD) model has been developed to predict the effect of different physical parameters including temperature and density on the mixing characteristics of the system. It is noted that non-isotropic nature of flow in a mixer-settler, the complex geometry of rotating impellers and the large disparity in geometric scales present are some of the factors which contribute to the simulation difficulty. The experimental data for different velocity outlet was also used in order to validate the model.

scholarly journals Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model

2016 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Ozkan Adiguzel ◽  
Mehmet Gokhan Gokcen ◽  
Ali Bahadir Olcay
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Root Canal ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Tilting Angle ◽  
Wall Shear

Aim: The Irrigant flow dynamics has strong influence on the root canal cleaning effectiveness. The aim of this study was to evaluate the effect of needle tilting angle on irrigant flow inside a prepared root canal during final irrigation with a side-vented needle using a validated Computational Fluid Dynamics (CFD) model. Methodology: To analyze the irrigant flow a CFD model with tilting angles of 0 and 2 degrees was created. The irrigant flow in the apical root canal was simulated. Computations were carried out for two selected flow rates of 0.26 and 0.78 mL/s to evaluate the velocity and turbulence quantities along the solution domain. Results: In addition to velocity and pressure distribution at the apex, wall shear stress distribution, vorticity and turbulent intensity results were obtained for needle tilting angle of 0 and 2 degrees. In the case of turbulent flows where the flow rate was higher, irrigation is better; however, higher apical pressures were observed for both tilting angles. Although the effect of tilting angle of two degrees for laminar flow was slightly better than zero degrees, the effect of tilting was significant for the turbulent flow case. Wall shear stress distribution, vorticity and turbulent intensity results were consistent with each other. Conclusions: A small tilting angle of 2 degrees had an effect on irrigation effectiveness which could be clearly observed from the wall shear stress, vorticity and velocity distribution results. The velocity distribution results obtained at the symmetry plane should be evaluated with the wall shear stress values together to observe the complete fluid dynamics structure inside the root canal.  How to cite this article: Adiguzel O, Gokcen MG, Olcay AB. Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model. Int Dent Res 2016;6:1-8.  Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Improvement performance of Al-Wathba settling tank by a computational fluid dynamics model

2010 ◽  
Vol 58 (3) ◽  
pp. 201-210 ◽  
Author(s):  
Jozef Kriš ◽  
Ghawi Hadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Settling Tank ◽  
The Body ◽  
Cfd Model ◽  
Dynamics Model ◽  
Measured Concentration ◽  
Computational Fluid Dynamics Model ◽  
Volume Method

Improvement performance of Al-Wathba settling tank by a computational fluid dynamics modelAn investigation has been carried out using the FLUENT Computational Fluid Dynamics (CFD) software, which uses the finite-volume method to determine whether it is feasible to improve the capacity and quality of the clarifier at the Al-Wathba Water Treatment Works (Iraq) by some relatively inexpensive means. Simulations were carried out with two dimensional, radially symmetric models, representing the existing configuration as well as a number of proposed modifications involving baffles and additional clarified water off-takes. A convection-diffusion equation, which is extended to incorporate the sedimentation of sludge flocs in the field of gravity, governs the mass transfer in the clarifier. The standardk-ε turbulence model is used to compute the turbulent motion, and our CFD model accounts for buoyancy flow. The sludge settling velocity was measured as a function of the concentration, and we have used the double-exponential settling velocity function to describe its dependence on the concentration. The CFD model is validated using measured concentration profiles. The results were evaluated on the basis of the simulated profiles of vertical up-flow velocity in the body of the clarifier.

Computational Fluid Dynamics Simulation of Steel Bars Cooling by Free Convection and Thermal Radiation

2015 ◽  
Vol 798 ◽  
pp. 170-174
Author(s):  
Paulo Henrique Terenzi Seixas ◽  
Paul Campos Santana Silva ◽  
Rudolf Huebner
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thermal Radiation ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Cfd Model ◽  
Computational Fluid Dynamics Simulation ◽  
Slow Cooling ◽  
Steel Bars ◽  
Computational Fluid Dynamics Cfd

In this article, the pilling process of hot steel bars is analyzed. During the loading three bars are placed over a wood surface, after those other three are placed over the previous for two times with 5 minutes intervals between them.They are all subject to a slow cooling by thermal radiation and free convection.A Computational Fluid Dynamics (CFD) model to predict the temperature profile of them is developed. Comparison between the CFD simulation results and experimental data yielded an average difference in the bars temperature between -0.3oC and 3.5oC.

A Two-Dimensional CFD Simulation for Different Spacers of Spiral Wound Moudles

2012 ◽  
Vol 557-559 ◽  
pp. 2249-2252 ◽  
Author(s):  
Song Lin Xu ◽  
Wen Qiang Mi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Cfd Simulation ◽  
Two Dimensional ◽  
Cfd Model ◽  
Visual Method ◽  
Unsteady Fluid Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Unsteady Fluid

A computational fluid dynamics (CFD) model was used to simulate unsteady fluid flow in a two-dimensional channel. The flow was computed for several different geometries and velocity. Calculations show different flow patterns of the cavity spacer, the submerged spacer and the zigzag spacer. Applications of two-dimensional CFD simulation give a visual method to determine the advantages of each spacer type.

CFD Simulation of Hydraulics of Dividing Wall Sieve Trays

2012 ◽  
Vol 476-478 ◽  
pp. 1345-1350
Author(s):  
Yan Wang ◽  
Song Du ◽  
Huai Gong Zhu ◽  
He Xu Ma ◽  
Shao Qing Zuo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
The Other ◽  
Phase Flow ◽  
Cfd Model ◽  
Two Phase ◽  
Sieve Tray ◽  
Commercial Scale ◽  
Computational Fluid Dynamics Cfd

A 3D two-phase flow computational fluid dynamics (CFD) model containing gas mal-distribution is developed in the Eulerian framework to predict the hydraulics of a dividing wall sieve tray. Variable and position dependent gas superficial velocity is used in the calculation. Using water-air system, simulations of flow patterns and hydraulics of a commercial- scale 1.2m diameter sieve tray are carried out using this model to testify its precision. Then, the same simulations of a dividing wall sieve tray with equal diameter are carried out. The results show that there are two backflow regions on a dividing wall tray, one is in the segmental area, and the other is in the region nearby junction of dividing wall and outlet weir. In the segmental area of trays with equal diameter, the area of backflow region of dividing wall trays is basically equal to that of conventional trays.

scholarly journals Computational fluid dynamics (CFD) analysis of mixing in styrene polymerization

2021 ◽  
Author(s):  
Haresh Patel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Residence Time ◽  
Cfd Simulation ◽  
Monomer Conversion ◽  
High Viscosity ◽  
Cfd Model ◽  
Input Output ◽  
Styrene Polymerization ◽  
Computational Fluid Dynamics Cfd

A styrene polymerization in a lab-scale CSTR equipped with a pitched blade turbine impeller was simulated using the computational fluid dynamics (CFD) approach. The impeller motion was integrated in the geometry using the multiple reference frame (MRF) technique. The presence of non-linear source term and the highly coupled nature of transport equations of the polymerization, made the convergence difficult to achieve. The effects of the impeller speed, the input-output locations and the residence time on the polymerization in the CSTR were investigated. The CFD simulation shows that good mixing remained limited to the impeller region. Regions far from the impeller remained unmixed due to high viscosity of the polymer mass. The path lines of the particles, released at the inlet, were also generated to analyze the reaction progress as the chemicals travel throughout the reactor. The monomer conversion computed using the CFD model was compared to data reported in the literature. Conversion predicted using the CFD model is in good agreement with that obtained from the CSTR model at low residence time. However, the CFD predicted coversions were higher than those calculated from the CSTR model, at high residence time. It was found that the input-output locations had significant effect on the conversion and the homogeneity in the CSTR.

scholarly journals Computational fluid dynamics (CFD) analysis of mixing in styrene polymerization

2021 ◽  
Author(s):  
Haresh Patel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Residence Time ◽  
Cfd Simulation ◽  
Monomer Conversion ◽  
High Viscosity ◽  
Cfd Model ◽  
Input Output ◽  
Styrene Polymerization ◽  
Computational Fluid Dynamics Cfd

A styrene polymerization in a lab-scale CSTR equipped with a pitched blade turbine impeller was simulated using the computational fluid dynamics (CFD) approach. The impeller motion was integrated in the geometry using the multiple reference frame (MRF) technique. The presence of non-linear source term and the highly coupled nature of transport equations of the polymerization, made the convergence difficult to achieve. The effects of the impeller speed, the input-output locations and the residence time on the polymerization in the CSTR were investigated. The CFD simulation shows that good mixing remained limited to the impeller region. Regions far from the impeller remained unmixed due to high viscosity of the polymer mass. The path lines of the particles, released at the inlet, were also generated to analyze the reaction progress as the chemicals travel throughout the reactor. The monomer conversion computed using the CFD model was compared to data reported in the literature. Conversion predicted using the CFD model is in good agreement with that obtained from the CSTR model at low residence time. However, the CFD predicted coversions were higher than those calculated from the CSTR model, at high residence time. It was found that the input-output locations had significant effect on the conversion and the homogeneity in the CSTR.

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