scholarly journals Progressive Wave Simulation Using Stabilized Edge-Based Finite Element Methods

2009 ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonc¸alves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperanc¸a ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Mass Conservation ◽  
Element Formulation ◽  
Normal Velocity ◽  
Offshore Platforms ◽  
Arbitrary Lagrangian Eulerian ◽  
Progressive Wave ◽  
Parallel Edge ◽  
Two Fluids ◽  
Edge Based

Flows involving waves and free-surfaces occur in several problems in hydrodynamics, such as sloshing in tanks, waves breaking in ships and motions of offshore platforms. The computation of such wave problems is challenging since the water/air interface (or free-surface) commonly present merging, fragmentation and cusps, leading to the use of interface capturing Arbitrary Lagrangian-Eulerian (ALE) approaches. In such methods the interface between the two fluids is captured by the use of a marking function which is transported in a flow field. In this work we simulate these problems with a 3D incompressible SUPG/PSPG parallel edge-based finite element flow solver associated to the Volume-of-Fluid (VOF) method [1]. The hyperbolic equation for the transport of the marking function is also solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity at the interface. The performance and accuracy of the proposed solution method is tested in the simulation of progressive waves and the interaction of a fixed cylinder with a progressive wave.

Computational Simulation of Free Surface Flows Using Stabilized Edge-Based Finite Element Method

2010 ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonc¸alves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperanc¸a ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Computational Simulation ◽  
Free Surface Flows ◽  
Element Formulation ◽  
Normal Velocity ◽  
Offshore Platforms ◽  
Arbitrary Lagrangian Eulerian ◽  
Parallel Edge ◽  
Edge Based

Flows involving waves and free-surfaces occur in several problems in hydrodynamics, such as sloshing in tanks, waves breaking in ship and motions of offshore platforms. The computation of such wave problems is challenging since the water/air interface (or free-surface) commonly present merging, fragmentation and cusps, leading to the use of interface capturing Arbitrary Lagrangian-Eulerian (ALE) approaches. In such methods the interface between the two fluids is captured by the use of a marking function which is transported in a flow field. In this work we simulate these problems with a 3D incompressible SUPG/PSPG parallel edge-based finite element flow solver associated to the Volume-of-Fluid (VOF) method [1]. The hyperbolic equation for the transport of the marking function is also solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity at the interface. The performance and accuracy of the proposed solution method is tested in the simulation of pulse wave and the interaction of a fixed square cylinder with a progressive wave.

A Stabilized Edge-Based Finite Element Approach to Wave-Structure Interaction Assessment

2013 ◽  
Author(s):  
Renato N. Elias ◽  
Alvaro L. G. A. Coutinho ◽  
Milton A. Gonçalves ◽  
Adriano M. A. Cortês ◽  
José L. Drummond Alves ◽  
...  
Keyword(s):  
Finite Element ◽  
Wave Structure ◽  
Element Formulation ◽  
Normal Velocity ◽  
Offshore Platforms ◽  
Arbitrary Lagrangian Eulerian ◽  
Parallel Edge ◽  
Free Surfaces ◽  
Highly Nonlinear ◽  
Edge Based

Complex flows involving waves and free-surfaces occur in several problems in hydrodynamics, such as fuel or water sloshing in tanks, waves breaking in ships, offshore platforms motions, wave action on harbors and coastal areas. The computation of such highly nonlinear flows is challenging since waves and free-surfaces commonly present merging, fragmentation and cusps, leading to the use of interface capturing Arbitrary Lagrangian-Eulerian (ALE) approaches. In such methods the interface between the two fluids is captured by the use of a marking function that is transported in a flow field. In this work we simulate these problems with a 3D incompressible SUPG/PSPG parallel edge-based finite element flow solver associated to the Volume-of-Fluid (VOF) method. The hyperbolic equation for the transport of the marking function is also solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity at the interface. All those techniques were successfully implemented in a computational code, which has been suitably used to carry out several studies. The performance and accuracy of the proposed solution method is tested in the simulation waves and in the interaction between waves and a semisubmersible structure. Results count on the establishment of a relaxation zone close to the domain outflow, which partially absorbs incoming waves, avoiding their reflection.

Computational Techniques for Stabilized Edge-Based Finite Element Simulation of Free-Surface Flows

2008 ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonc¸alves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperanc¸a ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Free Surface Flows ◽  
Computational Techniques ◽  
Element Formulation ◽  
Normal Velocity ◽  
Parallel Edge ◽  
Surface Flows ◽  
Highly Nonlinear ◽  
Edge Based

Free-surface flows occur in several problems in hydrodynamics, such as fuel or water sloshing in tanks, waves breaking in ships, offshore platforms, harbors and coastal areas. The computation of such highly nonlinear flows is challenging since free-surfaces commonly present merging, fragmentation and breaking parts, leading to the use of interface capturing Eulerian approaches. In such methods the surface between two fluids is captured by the use of a marking function which is transported in a flow field. In this work we discuss computational techniques for efficient implementation of 3D incompressible SUPG/PSPG finite element methods to cope with free-surface problems with the Volume-of-Fluid (VOF) method [1]. The pure advection equation for the scalar marking function was solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity of the interface. We introduce parallel edge-based data structures, a parallel dynamic deactivation algorithm to solve the marking function equation only in a small region around the interface. The implementation is targeted to distributed memory systems with cache-based processors. The performance and accuracy of the proposed solution method is tested in the simulation of the water impact on a square cylinder and in the propagation of a solitary wave.

EdgeCFD-ALE: A Stabilized Finite Element System for Fluid-Structure Interaction in Offshore Engineering

2012 ◽  
Author(s):  
José L. D. Alves ◽  
Carlos E. Silva ◽  
Nestor O. Guevara ◽  
Alvaro L. G. A. Coutinho ◽  
Renato N. Elias ◽  
...  
Keyword(s):  
Finite Element ◽  
Stokes Equations ◽  
Green Water ◽  
Offshore Platforms ◽  
Arbitrary Lagrangian Eulerian ◽  
Parallel Edge ◽  
Fluid Structure ◽  
Ale Formulation ◽  
Element System ◽  
Edge Based

This work presents the development of EdgeCFD-ALE, a finite element system for complex fluid-structure interactions designed for offshore hydrodynamics. Sloshing of liquids in tanks, wave breaking in ships, offshore platforms motions and green water on decks are important examples of these problems. The software uses edge-based parallel stabilized finite elements for the Navier-Stokes equations and the Volume-Of-Fluid method for the free-surface, both described by an Arbitrary Lagrangian Eulerian (ALE) formulation. Turbulence in is treated by a Smagorinsky model. Mesh updating is accomplished by a parallel edge-based solution of a non-homogeneous scalar diffusion problem in each spatial coordinate. Boundary conditions involve the motion of the immersed body’s surface, i.e., the fluid-structure interface, taken as the Lagrangian portion of the domain in the overall problem. The simulation capabilities of the present software are demonstrated in the solution of two problems, the interaction of two cylinders in tandem and the free fall of a sphere.

Computational Techniques for Stabilized Edge-Based Finite Element Simulation of Nonlinear Free-Surface Flows

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonçalves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperança ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Finite Element Simulation ◽  
Free Surface Flows ◽  
Computational Techniques ◽  
Normal Velocity ◽  
Parallel Edge ◽  
Surface Flows ◽  
Element Simulation ◽  
Edge Based

Free-surface flows occur in several problems in hydrodynamics, such as fuel or water sloshing in tanks, waves breaking in ships, offshore platforms, harbors, and coastal areas. The computation of such highly nonlinear flows is challenging, since free-surfaces commonly present merging, fragmentation, and breaking parts, leading to the use of interface-capturing Eulerian approaches. In such methods the surface between two fluids is captured by the use of a marking function, which is transported in a flow field. In this work we discuss computational techniques for efficient implementation of 3D incompressible streamline-upwind/Petrov–Galerkin (SUPG)/pressure-stabilizing/Petrov–Galerkin finite element methods to cope with free-surface problems with the volume-of-fluid method (Elias, and Coutinho, 2007, “Stabilized Edge-Based Finite Element Simulation of Free-Surface Flows,” Int. J. Numer. Methods Fluids, 54, pp. 965–993). The pure advection equation for the scalar marking function was solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced, adding or removing mass proportionally to the absolute value of the normal velocity of the interface. We introduce parallel edge-based data structures, a parallel dynamic deactivation algorithm to solve the marking function equation only in a small region around the interface. The implementation is targeted to distributed memory systems with cache-based processors. The performance and accuracy of the proposed solution method is tested in the simulation of the water impact on a square cylinder and in the propagation of a solitary wave.

F-Bar Aided Edge-Based Smoothed Finite Element Method with 4-Node Tetrahedral Elements for Static Large Deformation Elastoplastic Problems

2019 ◽  
Vol 16 (05) ◽  
pp. 1840010 ◽  
Author(s):  
Yuki Onishi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Element Formulation ◽  
Tetrahedral Elements ◽  
Smoothed Finite Element Method ◽  
New Type ◽  
Displacement Based ◽  
Edge Based ◽  
Element Method

A new type of smoothed finite element method (S-FEM), F-barES-FEM-T4, is demonstrated in static large deformation elastoplastic cases. F-barES-FEM-T4 combines the edge-based S-FEM (ES-FEM) and the node-based S-FEM (NS-FEM) for 4-node tetrahedral (T4) elements with the aid of the F-bar method in order to resolve the major issues of Selective ES/NS-FEM-T4. As well as most of the other S-FEMs, F-barES-FEM-T4 inherits pure displacement-based formulation and thus has no increase in DOF. Moreover, the cyclic smoothing procedure introduced in F-barES-FEM-T4 is effective to adjust the smoothing level so that pressure checkerboarding (oscillation) is suppressed reasonably. Some examples of static large deformation analyses for elastoplastic materials proof the excellent performance of F-barES-FEM-T4 in contrast to the conventional hybrid T4 element formulation.

The Implementation of the Level Set Method Within the Finite Element Formulation

2000 ◽  
Author(s):  
Sergey V. Shepel ◽  
Samuel Paolucci
Keyword(s):  
Finite Element ◽  
Level Set Method ◽  
Level Set ◽  
Mass Conservation ◽  
Significant Loss ◽  
Finite Element Formulation ◽  
Advection Equation ◽  
Element Formulation ◽  
Loss Of Mass ◽  
Finite Element Schemes

Abstract We apply the Streamline Upwind Petrov Galerkin (SUPG) finite element formulation of the Level Set method to 2D redistancing and advection problems on unstructured triangulated grids. The purpose is to test the Level Set method for mass conservation properties, where the mass is understood as the amount of fluid enclosed by the interface. For the redistancing procedure we implement the idea of mass correction suggested by Sussman and Fatemi (1999) and confirm its high accuracy within the finite element formulation. However, we find that the use of the first order SUPG formulation of the Level Set method for coupled redistancing-advection problems can result in significant loss of mass caused by distortion of the interface due to numerical diffusion. This neccesitates the use of higher order upwind finite element schemes for the advection equation.

Characterization of Distorted Fluid Flow Along Advanced High-Bypass Jet Engine Subjected to Foreign Object Ingestion

2017 ◽  
Author(s):  
Yangkun Song ◽  
Javid Bayandor
Keyword(s):  
Finite Element ◽  
Progressive Failure ◽  
Element Formulation ◽  
Foreign Object ◽  
Arbitrary Lagrangian Eulerian ◽  
Element Analysis ◽  
Jet Engine ◽  
Explicit Finite Element ◽  
Modeling Methodology ◽  
Explicit Finite Element Analysis

In this study, a non-linear fluid-solid interaction (FSI) methodology is uniquely developed to simulate the aerodynamic interaction and disturbance of flow along a high-bypass propulsion system subjected to foreign object ingestion (FOI). For the analysis, a time explicit finite element analysis is applied with an advanced computational scheme, Arbitrary Lagrangian-Eulerian (ALE). The advanced finite element formulation is able to successfully demonstrate the interaction between air and the high-bypass jet engine subjected to a soft body FOI by solving both solid and fluid continua simultaneously. As a result, the proposed damage modeling methodology simulates the progressive failure caused by the exertion of aerodynamics over the damaged and undamaged components.

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