Deficiencies in 2D Simulation: A Comparative Study of 2D Versus 3D Simulation of Multi-seam Longwall Mining

For the estimation of wave loads on offshore structures, relevant extreme wave events need to be identified. In order to achieve this, long-term wave simulations of relatively large scales need to be performed. Computational fluid dynamics (CFD) based numerical wave tanks with an interface capturing two-phase flow approach typically require too large computational resources. In this paper, a three-dimensional (3D) nonhydrostatic wave model is presented, which solves the Navier–Stokes equations and employs an interface tracking method based on the continuity of the horizontal velocities along the vertical water column. With this approach, relatively fewer cells are needed in the vicinity of the air–water interface compared to CFD-based numerical wave tanks. The numerical model solves the governing equations on a rectilinear grid, which allows for the employment of high-order finite differences. The capabilities of the new wave model are presented by comparing the wave propagation in the tank with the CFD approach in a two-dimensional (2D) simulation. Further, a 3D simulation is carried out to determine the wave forces on a vertical cylinder. The calculated wave forces using the new approach are compared to those obtained using the CFD approach and experimental data. It is seen that the new approach provides a similar accuracy to that from the CFD approach while providing a large reduction in the time taken for the simulation. The gain is calculated to be about 4.5 for the 2D simulation and about 7.1 for the 3D simulation.

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Comparative Study of 1D and 2D Simulation Models of Hollow RC Bridge Columns Under Reversed Cyclic Loads

Lecture Notes in Civil Engineering - Recent Advances in Structural Engineering, Volume 1 ◽

10.1007/978-981-13-0362-3_15 ◽

2018 ◽

pp. 183-191

Author(s):

Vijay Kumar Polimeru ◽

Abhideep Sahu ◽

Arghadeep Laskar

Keyword(s):

Comparative Study ◽

Simulation Models ◽

Bridge Columns ◽

Cyclic Loads ◽

2D Simulation ◽

Rc Bridge Columns ◽

Reversed Cyclic

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Can the numerical simulations of melting in a differentially-heated rectangular cavity be rationally reduced to 2D? A comparative study between 2D and 3D simulation results

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2020.120751 ◽

2021 ◽

Vol 166 ◽

pp. 120751

Author(s):

Nan Hu ◽

Li-Wu Fan ◽

Zi-Qin Zhu

Keyword(s):

Comparative Study ◽

Numerical Simulations ◽

Rectangular Cavity ◽

3D Simulation ◽

Simulation Results ◽

2D And 3D

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Development of Boss Forming Simulation Technologies with a Rotary Tool

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.504-506.949 ◽

2012 ◽

Vol 504-506 ◽

pp. 949-954

Author(s):

Yoshikazu Kobayashi ◽

Susumu Takahashi ◽

Eitaro Yukutake ◽

Shigeo Negishi

Keyword(s):

Magnesium Alloys ◽

Compression Test ◽

Alloy Sheet ◽

3D Simulation ◽

Material Loss ◽

Forming Simulation ◽

2D Simulation ◽

Ring Compression ◽

Forming Condition ◽

Better Than

Magnesium alloys are light weight and highly recyclable. To use magnesium alloys as parts of products such as automobiles, it is very effective make bosses by using plastic workings because this can reduce material loss and welding for producing parts. The bosses can be produced by a press cylindrical tool with rotation to the surface of the magnesium alloy sheet. To reduce the period of development of the tools in forming condition investigations, numerical simulation with FEM is very useful. FEM technologies have been developed for making bosses with plastic working. Because of the symmetry of the tool, the axisymmetrical FEM is applied as the first step. Bosses were found to increase in height as the friction coefficient increased. To investigate the friction between the tool and the alloy sheets, a ring compression test was conducted. The temperature of the alloy sheets increases as the bosses are formed. Therefore, the compression test was conducted at an elevated temperature. The heat transfer rate also affects the results of the forming simulation. To improve the shape of bosses from the simulation results, 3D simulation was performed. The shape of bosses in the 3D simulation is better than that in the 2D simulation by taking into account the traction at the contact area of the cylindrical tool.

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CFD Analysis of Unsteady Flows Around a New Cell-Truss Spar and the Corresponding Vortex-Induced Motions

Volume 5: Materials Technology; CFD and VIV ◽

10.1115/omae2008-57191 ◽

2008 ◽

Cited By ~ 1

Author(s):

Ying Wang ◽

Jianmin Yang ◽

Xin Li

Keyword(s):

Fluid Dynamic ◽

Unsteady Flows ◽

3D Simulation ◽

Nonlinear Flow ◽

Design Stage ◽

Experimental Investigations ◽

Ocean Engineering ◽

2D Simulation ◽

Hexahedral Elements ◽

Truss Spar

A new configuration of Spar platform called the Cell-Truss Spar has recently been put forward by State Key Laboratory of Ocean Engineering (SKLOE) of Shanghai Jiao Tong University. Since the Cell-Truss Spar is a new design concept that has several physical characteristics which are different from those of the present Classic, Truss and Cell Spars, many aspects of its performances in various sea conditions should be carefully studied. For any type of Spars, Vortex-Induced Motions (VIM) under current flow is an important consideration since it not only affects the motion performance of the Spar, but also reacts on the fatigue analysis and Spar mooring design. This paper mainly discusses the unsteady flows around the new Cell-Truss Spar and the corresponding vortex-induced motion performances of the Spar in uniform currents. A CFD model of the Cell-Truss Spar upper hull (without strake designs for VIM mitigation since it’s still at the concept design stage at the present time) with a scale ratio of 1:100 is created and numerical simulations at different current conditions are performed. The software FLUENT is chosen as the computational fluid dynamic tool to simulate the flow fields around the Cell-Truss Spar and the resulting vortex-induced motions. Both 2D and 3D simulations are carried out. Dynamic meshes and user defined functions are used in the fluid-structure interaction for solving the equations of motion. The SST k-ω method is used as the turbulence model in the 2D simulation and the Detached Eddy Simulation (DES) is used in the 3D simulation. In the 2D simulation, the unsteady flows around the Cell-Truss Spar hard tank at different Reynolds numbers are calculated and the corresponding vortex shedding features and other fluid parameters are obtained and analyzed. Moreover, in order to set up a baseline for the comparison and analysis of the Cell-Truss Spar, a typical Truss Spar hard tank with the same diameter and draft is also modeled and calculated. Comparisons with several classical experimental and numerical results are conducted to validate the numerical method. The Cell-Truss Spar hull VIM responses are then simulated. For the 3D simulation, the fluid domain is made of a hybrid mesh comprising of millions of wedgy and hexahedral elements. Since 3D simulation is very time-consuming, only the results of the nonlinear flow field features for the currents passing the stationary Spar are presented in this paper, and more advanced studies related to this subject including both numerical and experimental investigations would be carried out successively.

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Efficient Wave Modeling Using Non-Hydrostatic Pressure Distribution and Free Surface Tracking on Fixed Grids

Volume 2: CFD and FSI ◽

10.1115/omae2018-78158 ◽

2018 ◽

Author(s):

Hans Bihs ◽

Arun Kamath ◽

Ankit Aggarwal ◽

Csaba Pakozdi

Keyword(s):

Wave Propagation ◽

Free Surface ◽

Hydrostatic Pressure ◽

Numerical Model ◽

Wave Model ◽

Current Paper ◽

3D Simulation ◽

Wave Forces ◽

New Approach ◽

2D Simulation

For the estimation of wave loads on offshore structures, relevant extreme wave events need to be identified. In order to achieve this, long term wave simulations of relatively large scales need to be performed. Computational Fluid Dynamics (CFD) based Numerical Wave Tanks (NWT) with an interface capturing two-phase flow approach typically require too large computational resources to achieve this efficiently. They are more suitable for the near-field hydrodynamics of steep and breaking wave impacts on the structures. In the current paper, a three-dimensional non-hydrostatic wave model is presented. While it also solves the Navier-Stokes equations, it employs an interface tracking method for the calculation of the free surface location. The algorithm for the simulation of the free surface is based on the continuity of the horizontal velocities along the vertical water column. With this approach, relatively fewer cells are needed in the vicinity of the air-water interface compared to CFD based NWTs. With coarser grids and larger time steps, the wave propagation can be accurately predicted. The numerical model solves the governing equations on an rectilinear grid, which allows for the employment of high-order finite differences. For time stepping, a fractional step method with implicit treatment of the diffusion terms is employed. The projection method is used for the calculation of the non-hydrostatic pressure. The resulting Poisson equation is solved with Hypres geometric multigrid preconditioned conjugated gradient algorithm. The numerical model is parallelized following the domain decomposition strategy and MPI communication between the individual processors. In the current paper, the capabilities of the new wave model are presented by comparing the wave propagation in the tank with the CFD approach in a 2D simulation. Further, a 3D simulation is carried out to determine the wave forces on a vertical cylinder. The calculated wave forces using the new approach is compared to that obtained using the CFD approach and experimental data. It is seen that the new approach provides a similar accuracy to that from the CFD approach while providing a large reduction in the time taken for the simulation. The gain is calculated to be about 4.5 for the 2D simulation and about 7.1 for the 3D simulation.

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