Transcript Diapositiva 1 - Tor Vergata Karting

FSI Project
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University of Rome Tor Vergata
Modelling FSI problems in ANSYS
Fluent via UDF
[email protected]
Fluid-Structure Interaction (FSI)
A Fluid-Structure Interaction model is needed when:
• there are heavy fluid actions on
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deforming boundaries
it is not possible to neglect
deformations
phenomena are coupled and it is not
possible to study the problem
separating the structural and fluid
effects
e.g. Hemodynamics FSI problem
FSI Project
[email protected]
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University of Rome Tor Vergata
Benefits of FSI Simulation
• Investigate if problems are coupled
• Determine global performance difference comparing with
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the rigid case
Analyze local flow field changes
Analyze structural dynamic behaviour
Structural verification
Investigate if problems are physically stable/unstable and
determine transition conditions
FSI Project
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University of Rome Tor Vergata
The Proposed Product
• The Product aim is to allow FSI problems simulation entirely
within ANSYS Fluent
• A dedicated FEM solver has been developed by means of
UDF coding as plug in for ANSYS Fluent
• Dedicated Graphical User Interface (GUI) and Text User
Interface have been developed
• The Product has been tested, validated and used to simulate
practical and industrial cases
FSI Project
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University of Rome Tor Vergata
Our Strategy
More Time Steps ?
CFD Mesh
CFD Materials
CFD BCs
FEM Materials
FEM BCs
POST-PROCESSING
CFD Iterations
Next Timestep
Convergence ?
NO
INITIALIZATION
Pressures, shear
stresses and
contact forces
FEM Mesh is built
from CFD one
NO
Remeshing/Smoothing
New:
The product allows to
set structure material
properties and constraints
in the ANSYS FLUENT
code.
Displacements
FEM Iteration
New geometry
FSI Project
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University of Rome Tor Vergata
Product Features
• General robust FEM solver implemented
• Structural simulations in the range of small and large
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displacements, including non linear and contact problems
2D model for beams with implicit and explicit FEM approach
3D model for shells structure with implicit and explicit FEM
approach
Parallel implementation
Static and dynamic transient analysis
Multiphase and turbulence ANSYS Fluent model
Post-processing with ANSYS Fluent
FSI Project
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University of Rome Tor Vergata
Product strengths
• High efficiency
• Very light
The result is a very light code that leaves almost
unaffected the global CPU time
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General purpose
ANSYS Fluent users oriented
There are no interpolation errors
No other software knowledge is required
Highly customizable for client-oriented solutions, services
and consultancy.
FSI Project
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University of Rome Tor Vergata
Graphical User Interface
Dedicated GUI
in ANSYS Fluent
FSI Project
[email protected]
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University of Rome Tor Vergata
The CFD point of view
• Very often FSI problems are analysed by a structural point
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of view simulating the fluid with too simplified models
The present approach uses the CFD point of view
(ANSYS Fluent users point of view), focusing on how the
interaction with the structure influences the fluid behaviour
The CFD user is now allowed to set structure material
properties and constraints in order to easily simulate its
presence in a very family way
The knowledges of other software packages are not
required
FSI Project
[email protected]
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University of Rome Tor Vergata
Example of 3D model for shells structure (1)
FSI Interaction between a rectangular curtain and an air flow in a room.
This is an example in which
it is not possible to study the problem separating
structural and fluid effects
because there are heavy fluid actions on the curtain surface
and so it is necessary to consider its deformations
WINDOW
DOOR
CURTAIN
FSI Project
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University of Rome Tor Vergata
Example of 3D model for shells structure (2)
HW & SW configuration
Hardware:
• 2 AMD Opteron 2,2GHz Processor
• 16Gb RAM
Software:
• OS Linux Fedora 6
• ANSYS Fluent Version 6.3.23
• Version: 3ddp
Structural analysis solver used:
• Explicit
FSI Project
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University of Rome Tor Vergata
Example of 3D model for shells structure (3)
Case 1:
The curtain has the top edge constrained. It’s moved by the air flow
entering from the window and subjected to its dead load.
FSI Project
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University of Rome Tor Vergata
Example of 3D model for shells structure (4)
Case 2:
In this case the event of failure of curtain support is investigated.
The curtain is pushed by the air flow entering from the window and
it’s free to fall because the top edge constraint is missing.
FSI Project
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University of Rome Tor Vergata
Example of related areas
Hemodynamics and FSI Fluid-Structure Interaction
In this branch of medicine is necessary to consider the interaction
between the flowing blood and the vessels walls in order to investigate
and study many hemodynamics problems.
HW & SW configuration
Hardware:
• 2 AMD Opteron 2,2GHz Processor
• 16Gb RAM
Software:
• OS Linux Fedora 6
• ANSYS Fluent Version 6.3.23
• Version: 3ddp
Structural analysis solver used:
• Implicit solver working with MSC.NASTRAN solver
FSI Project
[email protected]
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University of Rome Tor Vergata
Example of hemodynamics problem (1)
The following picture represents the model of a Systemic-to-pulmonary
shunt that is a surgical procedure to treat complex congenital heart
defects.
It consists of an interposing tube between the sub-clavian artery and
the right pulmonary artery. In this case
it’s important to analyze the pressure drop across the shunt
which is affected by the blood pressure combined
with the distensibility of the shunt.
FSI Project
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University of Rome Tor Vergata
Example of hemodynamics problem (2)
SHUNT
FSI Project
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University of Rome Tor Vergata
Contact
University of Rome Tor Vergata
Dept. Mechanical Engineering
Via del Politecnico,1 – Rome, ITALY
e-mail: [email protected]
Tel: +39 06 7259 7124 - Dr. Marco E. Biancolini
FSI Project
[email protected]
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University of Rome Tor Vergata