Computational Fluid Dynamics Simulations of Nonlinear Sloshing in a Rotating Rectangular Tank Using the Level Set Method

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Erlend Liavåg Grotle ◽  
Hans Bihs ◽  
Vilmar Æsøy ◽  
Eilif Pedersen
Keyword(s):  
Numerical Model ◽  
Level Set Method ◽  
Level Set ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Turbulence Energy ◽  
Limiting Factor ◽  
Nonlinear Sloshing ◽  
Interface Location ◽  
Dynamics Simulations

In this paper, numerical simulations of nonlinear sloshing in rectangular tanks are presented. Model implementations in the open source software reef3d are tested, and the results are compared with experimental data from three different conditions. The interface location is compared for both linear and nonlinear sloshing. The nonlinear sloshing is simulated in both two-dimensional (2D) and three-dimensional (3D). Video images from the SPHERIC project are compared with simulations for the interface. A condition with lateral wave impacts in sloshing, with a frequency close to the natural frequency of the first mode, can be found in this case. The numerical model is solving the Reynolds-averaged Navier–Stokes (RANS) equations with the k–ω turbulence model. The level set method is used to capture the interface. Higher order discretization schemes are implemented to handle time-evolution and convective fluxes. A ghost cell method is used to account for solid boundaries and parallel computations. It is found that the limiting factor for the eddy-viscosity has significant influence in the nonlinear sloshing cases. As the sloshing becomes more violent, the increased strain at the gas–liquid interface overproduces turbulence energy with unrealistically high damping of the motion. Three-dimensional simulations show slightly better comparison than 2D. Due to nonlinearities and small damping, the time to reach steady-state may take several cycles. The last case shows promising results for the global motion. As expected, the breakup of the liquid surface makes it difficult to resolve each phase. But overall, the numerical model predicts the sloshing motion reasonably well.

CFD Simulations of Non-Linear Sloshing in a Rotating Rectangular Tank Using the Level Set Method

2016 ◽  
Author(s):  
Erlend Liavåg Grotle ◽  
Hans Bihs ◽  
Eilif Pedersen ◽  
Vilmar Æsøy
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Time Evolution ◽  
Level Set Method ◽  
Level Set ◽  
Turbulence Energy ◽  
Limiting Factor ◽  
Surface Time ◽  
Non Linear ◽  
Multiple Grids

In this paper, numerical simulations of non-linear sloshing in rectangular tanks are presented. Model implementations in the open source software REEF3D are tested and results compared with experimental data. Three different conditions are compared with experiments in 2D. First, the free surface time-evolution is compared for both linear and non-linear sloshing. In the last case, video images from the SPHERIC project are compared with simulations images of the free surface. A condition with lateral wave impacts in sloshing, with a frequency closer to the natural frequency of the first mode, can be found in this case. The non-linear sloshing, case 2, is also simulated in 3D. The numerical model is solving the RANS equations with the k-ω turbulence model. The level set method is used to capture the interface. Higher order discretization schemes are implemented to handle time-evolution and convective fluxes. A ghost cell method is used to account for solid boundaries and multiple grids for parallel computations. It is found that the limiting factor for the eddy-viscosity has significant influence in case 2 and 3. As the sloshing becomes more violent, the increased strain at the gas-liquid interface overproduces turbulence energy with unrealistically high damping of the motion. 3D simulations are only performed in case 2, which shows slightly better comparison than with 2D. Due to non-linearities and small damping, the time to reach steady-state may take several cycles, but no information is given in the paper [1]. The last case shows promising results for the global motion. As expected, the break up of the liquid surface makes it difficult to resolve each phase. But overall, the numerical model predicts the sloshing motion reasonably well.

Three-Dimensional Numerical Modeling of Pier Scour Under Current and Waves Using Level-Set Method

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Mohammad Saud Afzal ◽  
Hans Bihs ◽  
Arun Kamath ◽  
Øivind A. Arntsen
Keyword(s):  
Free Surface ◽  
Level Set Method ◽  
Level Set ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Navier Stokes ◽  
Reasonable Assumption ◽  
Cfd Model ◽  
Time Step ◽  
Pier Scour

A three-dimensional (3D) computational fluid dynamics (CFD) model is used to calculate the scour and the deposition pattern around a pier for two different boundary conditions: constant discharge and regular waves. The CFD model solves Reynolds-Averaged Navier–Stokes (RANS) equations in all three dimensions. The location of the free-surface is represented using the level-set method (LSM), which calculates the complex motion of the free-surface in a very realistic manner. For the implementation of waves, the CFD code is used as a numerical wave tank. For the geometric representation of the moveable sediment bed, the LSM is used. The numerical results for the local scour prediction are compared with physical experiments. The decoupling of the hydrodynamic and the morphodynamic time step is tested and found to be a reasonable assumption. For the two situations of local pier scour under current and wave conditions, the numerical model predicts the general evolution (geometry, location, and maximum scour depth) and time development of the scour hole accurately.

Element-local level set method for three-dimensional dynamic crack growth

2009 ◽  
Vol 80 (12) ◽  
pp. 1520-1543 ◽  
Author(s):  
Qinglin Duan ◽  
Jeong-Hoon Song ◽  
Thomas Menouillard ◽  
Ted Belytschko
Keyword(s):  
Crack Growth ◽  
Level Set Method ◽  
Level Set ◽  
Local Level ◽  
Three Dimensional ◽  
Dynamic Crack ◽  
Dynamic Crack Growth ◽  
Local Level Set

scholarly journals Computing three-dimensional two-phase flows with a mass-conserving level set method

2008 ◽  
Vol 11 (4-6) ◽  
pp. 221-235 ◽  
Author(s):  
S. P. van der Pijl ◽  
A. Segal ◽  
C. Vuik ◽  
P. Wesseling
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Three Dimensional ◽  
Two Phase Flows ◽  
Two Phase

scholarly journals A topology optimisation for three-dimensional acoustics with the level set method and the fast multipole boundary element method

2014 ◽  
Vol 1 (4) ◽  
pp. CM0039-CM0039 ◽  
Author(s):  
Hiroshi ISAKARI ◽  
Kohei KURIYAMA ◽  
Shinya HARADA ◽  
Takayuki YAMADA ◽  
Toru TAKAHASHI ◽  
...  
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Level Set Method ◽  
Level Set ◽  
Three Dimensional ◽  
Topology Optimisation ◽  
Fast Multipole ◽  
Element Method

scholarly journals A numerical geotechnical model for computing soil slides at banks of water reservoirs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nils Reidar B. Olsen ◽  
Stefan Haun
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Stokes Equations ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Field Measurements ◽  
Navier Stokes ◽  
Adaptive Grids ◽  
Groundwater Levels ◽  
Before And After

AbstractSoil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical model used for the simulation of reservoir flushing that includes the slide movements. The geotechnical failure algorithms start with modelling the groundwater levels at the banks of the reservoir. A limit equilibrium approach is further used to find the location of the slides. The actual movement of the sediments is computed by assuming the soil to be a viscous liquid and by solving the Navier–Stokes equations. The resulting bed elevation changes from the slides are computed in adaptive grids that change as a function of water level, bed erosion and slide movements. The numerical model is tested on the Bodendorf reservoir in Austria, where field measurements are available of the bank elevations before and after a flushing operation. The results from the numerical simulations are compared with these observations. A parameter test shows that the results are very sensitive to the cohesion and less sensitive to the E and G modules of the soil.

Numerical Modelling of Circulation in Lake Sperillen, Norway

2000 ◽  
Vol 31 (1) ◽  
pp. 57-72 ◽  
Author(s):  
N. R. B. Olsen ◽  
D. K. Lysne
Keyword(s):  
Numerical Model ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Field Measurements ◽  
Navier Stokes ◽  
Water Current ◽  
Simple Method ◽  
Vertical Temperature Profile ◽  
Navier Stokes Equations ◽  
Good Agreement

A three-dimensional numerical model was used to model water circulation and spatial variation of temperature in Lake Sperillen in Norway. A winter situation was simulated, with thermal stratification and ice cover. The numerical model solved the Navier-Stokes equations on a 3D unstructured non-orthogonal grid with hexahedral cells. The SIMPLE method was used for the pressure coupling and the k-ε model was used to model turbulence, with a modification for density stratification due to the vertical temperature profile. The results were compared with field measurements of the temperature in the lake, indicating the location of the water current. Reasonably good agreement was found.

scholarly journals Performance assessment of density and level-set topology optimisation methods for three dimensional heat sink design

2018 ◽  
Vol 12 (3) ◽  
pp. 273-287 ◽  
Author(s):  
Mani Sekaran Santhanakrishnan ◽  
Timothy Tilford ◽  
Christopher Bailey
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Heat Sink ◽  
Three Dimensional ◽  
Engineering Problem ◽  
Topology Optimisation ◽  
Design Quality ◽  
Advantages And Disadvantages ◽  
Computational Speed ◽  
Heat Sink Design

In this paper, two most prevalent topological optimisation approaches namely Density and Level set method are applied to a three dimensional heat sink design problem. The relative performance of the two approaches is compared in terms of design quality, robustness and computational speed. The work is original as for the first time it demonstrates the relative advantages and disadvantages for each method when applied to a practical engineering problem. It is additionally novel in that it presents the design of a convectively cooled heat sink by solving full thermo-fluid equations for two different solid-fluid material sets. Further, results are validated using a separate computational fluid dynamics study with the optimised designs are compared against a standard pin-fin-based heat sink design. The results show that the Density method demonstrates better performance in terms of robustness and computational speed, while Level-set method yields a better quality design in terms of final objective value.

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