Numerical Investigation of Fluid-Ice-Structure Interaction During Collision by an Arbitrary Lagrangian Eulerian Method

2016 ◽  
Author(s):  
Ming Song ◽  
Ekaterina Kim ◽  
Jørgen Amdahl ◽  
Marilena Greco ◽  
Mhamed Souli
Keyword(s):  
Structural Design ◽  
Sensitivity Study ◽  
Contact Forces ◽  
Theoretical Modelling ◽  
Water Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Ocean Engineering ◽  
Noticeable Effect ◽  
Structure Interaction ◽  
Ale Formulation

When ice floes collide against marine structures, pronounced hydrodynamic loads are induced by the water-ice-structure interaction. With today’s highly competitive structural design market, it is nearly impossible to ignore the advances that have been made in the computer analysis of fluid-structure interaction (FSI) problems. FSI methods can provide accurate representation of hydrodynamic effects. A number of commercial programs have been developed, and their applications in structural design increases rapidly. For instance, Arbitrary Lagrangian-Eulerian (ALE) formulations have been used to solve underwater explosions problems in ocean engineering, and soil-structure interaction problems in civil engineering. Application to fluid-ice-structure interaction problems is more recent and growing. This paper represents a contribution in assessing the capabilities of the ALE formulation for fluid-ice-structure collision problems. The ALE and coupling algorithms have been successfully validated through the comparison against model tests of an ice-structure collision. The work also examines the numerical convergence and the sensitivity of the results to the theoretical modelling used. From the sensitivity study it is concluded that the effect of viscosity and equation of state for the water model within the ALE formulation are insignificant, whereas the choice of the element size has a noticeable effect on the computed contact forces and the motions of the impacted structure.

Dynamic Time-History Response of Cylindrical Tank Considering Fluid - Structure Interaction due to Earthquake

2014 ◽  
Vol 617 ◽  
pp. 66-69 ◽  
Author(s):  
Kamila Kotrasova ◽  
Ivan Grajciar ◽  
Eva Kormaníková
Keyword(s):  
Fluid Structure Interaction ◽  
Time History ◽  
Problem Analysis ◽  
Arbitrary Lagrangian Eulerian ◽  
Cylindrical Tank ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Ale Formulation ◽  
Time History Response ◽  
Dynamic Time

Ground-supported cylindrical tanks are used to store a variety of liquids. The fluid was develops a hydrodynamic pressures on walls and bottom of the tank during earthquake. This paper provides dynamic time-history response of concrete open top cylindrical liquid storage tank considering fluid-structure interaction due to earthquake. Numerical model of cylindrical tank was performed by application of the Finite Element Method (FEM) utilizing software ADINA. Arbitrary-Lagrangian-Eulerian (ALE) formulation was used for the problem analysis. Two way Fluid-Structure Interaction (FSI) techniques were used for the simulation of the interaction between the structure and the fluid at the common boundary

scholarly journals 3D Numerical Simulation of Seamless Pipe Piercing Process by Fluid-Structure Interaction Method

2018 ◽  
Vol 203 ◽  
pp. 06016 ◽  
Author(s):  
Ameen Topa ◽  
Do Kyun Kim ◽  
Youngtae Kim
Keyword(s):  
Numerical Simulations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Rolling Process ◽  
Arbitrary Lagrangian Eulerian ◽  
Analysis Method ◽  
Seamless Pipe ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Ale Formulation

Seamless pipes are produced using piercing rolling process in which round bars are fed between two rolls and pierced by stationary plug. During this process, the material undergoes severe deformation which renders it impractical to perform the numerical simulations with conventional finite element methods. In this paper, three dimensional numerical simulations of the piercing process are performed with Fluid-Structure Interaction (FSI) Method using Arbitrary Lagrangian-Eulerian (ALE) Formulation with LS DYNA software. The results of numerical simulations agree with experimental data of Plasticine workpiece and the validity of the analysis method is confirmed.

Numerical Analysis of Hydrofoil Dynamics by Using a Fluid-Structure Interaction Approach

2012 ◽  
Author(s):  
Tolotra Emerry Rajaomazava ◽  
Mustapha Benaouicha ◽  
Jacques-André Astolfi
Keyword(s):  
Stokes Problem ◽  
Fluid Structure Interaction ◽  
Time Discretization ◽  
Navier Stokes ◽  
Arbitrary Lagrangian Eulerian ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Ale Formulation ◽  
Non Linear ◽  
Interaction Approach

In this paper, the flow over pitching and heaving hydrofoil is investigated. The viscous incompressible Navier-Stokes problem in Arbitrary Lagrangian-Eulerian (ALE) formulation is solved using the finite elements code Cast3M. The projection method is used to uncouple the velocity and pressure fields. The implicit Euler scheme is applied for time discretization of fluid equations. The dynamics of the hydrofoil is governed by a non-linear ordinary differential equation. The non-linear coupled problem is solved using the explicit staggered algorithm. The effects of fluid-structure interaction on hydrofoil dynamics and pressure center position are analyzed.

A Consistent Implementation of Inelastic Material Models into Steady State Rolling

2016 ◽  
Vol 44 (3) ◽  
pp. 174-190 ◽  
Author(s):  
Mario A. Garcia ◽  
Michael Kaliske ◽  
Jin Wang ◽  
Grama Bhashyam
Keyword(s):  
Steady State ◽  
Numerical Simulations ◽  
Viscoelastic Material ◽  
Rolling Contact ◽  
Arbitrary Lagrangian Eulerian ◽  
Ale Formulation ◽  
Inelastic Material ◽  
Material Formulation ◽  
Steady State Rolling ◽  
Efficient Alternative

ABSTRACT Rolling contact is an important aspect in tire design, and reliable numerical simulations are required in order to improve the tire layout, performance, and safety. This includes the consideration of as many significant characteristics of the materials as possible. An example is found in the nonlinear and inelastic properties of the rubber compounds. For numerical simulations of tires, steady state rolling is an efficient alternative to standard transient analyses, and this work makes use of an Arbitrary Lagrangian Eulerian (ALE) formulation for the computation of the inertia contribution. Since the reference configuration is neither attached to the material nor fixed in space, handling history variables of inelastic materials becomes a complex task. A standard viscoelastic material approach is implemented. In the inelastic steady state rolling case, one location in the cross-section depends on all material locations on its circumferential ring. A consistent linearization is formulated taking into account the contribution of all finite elements connected in the hoop direction. As an outcome of this approach, the number of nonzero values in the general stiffness matrix increases, producing a more populated matrix that has to be solved. This implementation is done in the commercial finite element code ANSYS. Numerical results confirm the reliability and capabilities of the linearization for the steady state viscoelastic material formulation. A discussion on the results obtained, important remarks, and an outlook on further research conclude this work.

scholarly journals The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model

2006 ◽  
Vol 6 (1) ◽  
pp. 67-80 ◽  
Author(s):  
A. Teller ◽  
Z. Levin
Keyword(s):  
Water Vapor ◽  
Climate Models ◽  
Cloud Model ◽  
Cloud Condensation Nuclei ◽  
Sensitivity Study ◽  
Meteorological Conditions ◽  
Dust Particles ◽  
Noticeable Effect ◽  
Convective Clouds ◽  
Ice Nuclei

Abstract. Numerical experiments were carried out using the Tel-Aviv University 2-D cloud model to investigate the effects of increased concentrations of Cloud Condensation Nuclei (CCN), giant CCN (GCCN) and Ice Nuclei (IN) on the development of precipitation and cloud structure in mixed-phase sub-tropical convective clouds. In order to differentiate between the contribution of the aerosols and the meteorology, all simulations were conducted with the same meteorological conditions. The results show that under the same meteorological conditions, polluted clouds (with high CCN concentrations) produce less precipitation than clean clouds (with low CCN concentrations), the initiation of precipitation is delayed and the lifetimes of the clouds are longer. GCCN enhance the total precipitation on the ground in polluted clouds but they have no noticeable effect on cleaner clouds. The increased rainfall due to GCCN is mainly a result of the increased graupel mass in the cloud, but it only partially offsets the decrease in rainfall due to pollution (increased CCN). The addition of more effective IN, such as mineral dust particles, reduces the total amount of precipitation on the ground. This reduction is more pronounced in clean clouds than in polluted ones. Polluted clouds reach higher altitudes and are wider than clean clouds and both produce wider clouds (anvils) when more IN are introduced. Since under the same vertical sounding the polluted clouds produce less rain, more water vapor is left aloft after the rain stops. In our simulations about 3.5 times more water evaporates after the rain stops from the polluted cloud as compared to the clean cloud. The implication is that much more water vapor is transported from lower levels to the mid troposphere under polluted conditions, something that should be considered in climate models.

Iterative method for solving fully-coupled fluid solid systems

2010 ◽  
pp. 653-670
Author(s):  
Elisabeth Longatte
Keyword(s):  
Stokes Equations ◽  
Cross Flow ◽  
Elastic Cylinder ◽  
Navier Stokes ◽  
Arbitrary Lagrangian Eulerian ◽  
Navier Stokes Equations ◽  
Ale Formulation ◽  
Volume Method ◽  
Fully Coupled ◽  
Solid System

This work is concerned with the modelling of the interaction of a fluid with a rigid or a flexible elastic cylinder in the presence of axial or cross-flow. A partitioned procedure is involved to perform the computation of the fully-coupled fluid solid system. The fluid flow is governed by the incompressible Navier-Stokes equations and modeled by using a fractional step scheme combined with a co-located finite volume method for space discretisation. The motion of the fluid domain is accounted for by a moving mesh strategy through an Arbitrary Lagrangian-Eulerian (ALE) formulation. Solid dyncamics is modeled by a finite element method in the linear elasticity framework and a fixed point method is used for the fluid solid system computation. In the present work two examples are presented to show the method robustness and efficiency.

Fluid-Structure Interaction Approach for Numerical Investigation of a Flexible Hydrofoil Deformations in Turbulent Fluid Flow

2018 ◽  
Author(s):  
M. Benaouicha ◽  
S. Guillou ◽  
A. Santa Cruz ◽  
H. Trigui
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Time Step ◽  
Fluid Structure ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Structure Interaction ◽  
Ale Formulation

The study deals with a 3D Fluid-Structure Interaction (FSI) numerical model of a rectangular cantilevered flexible hydrofoil subjected to a turbulent fluid flow regime. The structural response and dynamic deformations are studied by analyzing the oscillations frequencies and amplitudes, under a hydrodynamics loads. The obtained numerical results are confronted with experimental ones, for validation. The numerical model is performed in the same geometric, physical and material conditions as the experimental set-up carried out in a hydrodynamic tunnel. A polyacetal (POM) flexible hydrofoil NACA0015 with an angle of attack of 8° is considered to be immersed in a fluid flow at a Reynold number of 3 × 105. The structure is initially at rest and then moved by the action of the fluid flow. The numerical model is based on a strong coupling procedure for solving the Fluid-Structure Interaction problem. The Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations is used and an anisotropic diffusion equation is solved to compute the fluid mesh velocity and position at each time step. The finite volume method is used for the numerical resolution of the fluid dynamics equations. The structure deformations are described by the linear elasticity equation which is solved by the finite elements method. The Fluid-Structure coupled problem is solved by using the partitioned FSI implicit algorithm. A good agreement between numerical and experimental results for the hydrodynamics coefficients and hydrofoil deformations, maximum deflection and frequencies is obtained. The added mass and damping are analyzed and then the FSI effect on the dynamic deformations of the structure is highlighted.

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