The fluid-structure interaction and the fluid flow are studied in cases of a fuel tank sloshing and overturning. A
bi-phase liquid-gas material with an ALE formulation is used to define the interaction between water and air in the
fuel tank.
Sloshing inside a fuel tank by simulating the fluid structure coupling. The tank deformation is achieved by applying
an imposed velocity on the left corners. Water and air inside the tank are modeled with the ALE formulation. The tank
container is described using a Lagrangian formulation.
Fuel tank overturning with simulation of the fluid flow. The reversing tank is modeled using horizontally-applied
gravity. The tank container is presumed without deformation and only the water and air inside the tank are taken into
consideration using the ALE formulation.
The purpose of this example is to study the energy propagation and the momentum transfer through several bodies, initially
in contact with each other, subjected to multiple impact. The process of collision and the energetic behavior upon
impact are described using a 3-dimensional mode.
The impact and rebound between balls on a small billiard table is studied. This example deals with the problem of
defining interfaces and transmitting momentum between the balls.
After a quasi-static pre-loading using gravity, a dummy cyclist rides along a plane, then jumps down onto a lower
plane. Sensors are used to simulate the scenario in terms of time.
The purpose of this study is to demonstrate the use of quadratic interface contact using two gears in contact with
identical pitch diameter and straight teeth. Two different contact interfaces are compared.
The problem of a dummy positioning on the seat before a crash analysis is the quasi-static loading which can be resolved
by either Radioss explicit or Radioss implicit solvers.
The crashing of a box beam against a rigid wall is a typical and famous example of simulation in dynamic transient
problems. The purpose for this example is to study the mesh influence on simulation results when several kinds of
shell elements are used.
A square plane subjected to in-plane and out-of-plane static loading is a simple element test. It allows you to highlight
element formulation for elastic and elasto-plastic cases. The under-integrated quadrilateral shells are compared with
the fully-integrated BATOZ shells. The triangles are also studied.
The modeling of a camshaft, which takes the engine's rotary motion and translates it into linear motion for operating
the intake and exhaust valves, is studied.
The ditching of an object into a pool of water is studied using SPH and ALE approaches. The simulation results are
compared to the experimental data and to the analytical results.
A rubber ring resting on a flat rigid surface is pushed down by a circular roller to produce self-contact on the inside
surface of the ring. Then the roller is simultaneously rolled and translated so that crushed ring rolls along the
flat surface.
Polynomial EOS is used to model perfect gas. Pressure or energy can be absolute values or relative. Material LAW6
(/MAT/HYDRO) is used to build material cards for each of these cases.
Separate the whole model into main domain and sub-domain and solve each one with its own timestep. The new Multi-Domain
Single Input Format makes the sub-domain part definition with the /SUBDOMAIN keyword.
The Cylinder Expansion Test is an experimental test used to characterize the adiabatic expansion of detonation products.
It allows determining JWL EOS parameters.
The aim of this example is to introduce /INIVOL for initial volume fractions of different materials in multi-material ALE elements, /SURF/PLANE for infinite plane, and fluid structure interaction (FSI) with a Lagrange container.
A heat source moved on one plate. Heat exchanged between a heatsource and a plate through contact, also between a
plate and theatmosphere (water) through convective flux.
Impacts of rotating structures usually happen while the structure is rotating at a steady state. When the structure is
rotating at very high speeds, it is necessary to include the centrifugal force field acting on the structure to correctly
account for the initial stresses in the structure due to rotation.
The fluid-structure interaction and the fluid flow are studied in cases of a fuel tank sloshing and overturning. A
bi-phase liquid-gas material with an ALE formulation is used to define the interaction between water and air in the
fuel tank.
Sloshing inside a fuel tank by simulating the fluid structure coupling. The tank deformation is achieved by applying
an imposed velocity on the left corners. Water and air inside the tank are modeled with the ALE formulation. The tank
container is described using a Lagrangian formulation.
Sloshing inside a fuel tank by simulating the fluid structure coupling. The tank
deformation is achieved by applying an imposed velocity on the left corners. Water and air
inside the tank are modeled with the ALE formulation. The tank container is described using
a Lagrangian formulation.
A numerical simulation of fluid-structure coupling is performed on sloshing inside a
deformable fuel tank. This example uses the ALE (Arbitrary Lagrangian Eulerian)
formulation and the hydrodynamic bi-material law (/MAT/LAW37) to
model interaction between water, air and the tank container.
Options and Keywords Used
Fluid structure coupling simulation, and ALE formulation
Velocities (/IMPVEL) are imposed on the left corners in the X
direction.
Table 1. Imposed Velocity versus Time Curve
Velocity
(ms-1)
0
5
0
0
Time (ms)
0
12
12.01
50
Regarding the ALE boundary conditions, constraints are applied on:
Material velocity
Grid velocity
All nodes, except those on the border have grid (/ALE/BCS) and
material (/BCS) velocities fixed in the Z-direction. The nodes on
the border only have a material velocity (/BCS) fixed in the
Z-direction.
Both the ALE materials air and water must be declared ALE using
/ALE/MAT.
Note: Lagrangian material is automatically declared
Lagrangian.
The /ALE/GRID/DONEA option activates the J. Donea grid formulation
to compute the grid velocity. See the Radioss
Theory Manual for further explanations about this option.
A rectangular tank made of steel is partially filled with water, the remainder being supplemented by air. The initial distribution pressure is known and supposed homogeneous. The tank container dimensions are 460 mm x 300 mm x 10 mm, with thickness being at 2 mm.
Deformation of the tank container is generated by an impulse made on the left corners of the tank
for analyzing the fluid-structure coupling.
The steel container is modeled using the elasto-plastic model of Johnson-Cook law
(/MAT/LAW2) with the following parameters:
Material Properties
Density
0.0078
Young's modulus
210000
Poisson's ratio
0.29
Yield stress
180
Hardening parameter
450
Hardening exponent
0.5
The material air-water bi-phase is described in the hydrodynamic bi-material liquid-gas law
(/MAT/LAW37). Material LAW37 is specifically designed to
model bi-material liquid gas.
The equations used to describe the state of viscosity and pressure are:
Viscosity
Liquid EOS
Where, and
Gas EOS
Where, as special volume
The equilibrium is defined by:
Where,
Deviatoric stress tensor
Deviatoric strain tensor
Material Parameters - For Liquid
Liquid reference density,
0.001
Liquid bulk modulus,
2089 N/mm2
Initial mass fraction liquid proportion,
100%
Shear kinematic viscosity ,
0.001 mm2/ms
Material Parameters - For Gas
Gas reference density,
1.22x10-6
Shear kinematic viscosity ,
0.00143 mm2/ms
Constant perfect gas,
1.4
Initial pressure reference gas,
0.1 N/mm2
The main solid TYPE14 properties for air/water parts are:
Properties
Quadratic bulk viscosity/linear bulk viscosity
10-20
Hourglass bulk coefficient
10-5
Model Method
Air and water are modeled using the ALE formulation and the bi-material law
(/MAT/LAW37). The tank container uses a Lagrangian
formulation and an elasto-plastic material law (/MAT/LAW2).
Using the ALE formulation, the brick mesh is only deformed by tank deformation the
water flowing through the mesh. The Lagrangian shell nodes still coincide with the
material points and the elements deform with the material: this is known as a
Lagrangian mesh. For the ALE mesh, nodes on the boundaries are fixed in order to
remain on the border, while the interior nodes are moved.
Results
Curves and Animations
Fluid - Structure Coupling
Kinematic conditions generate oscillations of the structure.