Modelling FSI problems in ANSYS Fluent via UDF
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Transcript of Modelling FSI problems in ANSYS Fluent via UDF
FSI ProjectFSI ProjectSpin off Spin off
UniversityUniversity of Rome Tor Vergata of Rome Tor Vergata
Modelling FSI problems in Modelling FSI problems in ANSYS ANSYS FluentFluent via UDF via UDF
FSI ProjectSpin off
University of Rome Tor [email protected]
Fluid-Structure Interaction (FSI)Fluid-Structure Interaction (FSI)
•there are heavy fluid actions on
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
A Fluid-Structure Interaction model is needed when:
e.g. Hemodynamics FSI problem
FSI ProjectSpin off
University of Rome Tor [email protected]
Benefits of FSI SimulationBenefits of FSI Simulation
• Investigate if problems are coupled
• Determine global performance difference comparing with
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 ProjectSpin off
University of Rome Tor [email protected]
The ProposedThe Proposed Product 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 ProjectSpin off
University of Rome Tor [email protected]
Our StrategyOur Strategy
Pressures, shear stresses and
contact forces
Displacements
NO
NO
New: The product allows to set structure material properties and constraints in the ANSYS FLUENTcode.
CFD Mesh CFD Materials CFD BCs FEM Materials FEM BCs
INITIALIZATION
FEM Mesh is built from CFD one
FEM Iteration
Convergence ?
CFD Iterations
More Time Steps ?
Remeshing/Smoothing
Next Timestep
New geometry
POST-PROCESSING
FSI ProjectSpin off
University of Rome Tor [email protected]
Product FeaturesProduct Features
• General robust FEM solver implemented
• Structural simulations in the range of small and large
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 ProjectSpin off
University of Rome Tor [email protected]
The result is a very light code that leaves almost unaffected the global CPU time
• High efficiency
• Very light
• 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.
Product strengthsProduct strengths
FSI ProjectSpin off
University of Rome Tor [email protected]
Graphical User InterfaceGraphical User Interface
Dedicated GUIin ANSYS Fluent
FSI ProjectSpin off
University of Rome Tor [email protected]
The CFD point of viewThe CFD point of view
• Very often FSI problems are analysed by a structural point
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 ProjectSpin off
University of Rome Tor [email protected]
Example of 3D model for shells structure (1)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
because there are heavy fluid actions on the curtain surfaceand so it is necessary to consider its deformations
WINDOW
CURTAIN
DOOR
it is not possible to study the problem separating structural and fluid effects
FSI ProjectSpin off
University of Rome Tor [email protected]
Example of 3D model for shells structure (2)Example of 3D model for shells structure (2)
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
HW & SW configurationHW & SW configuration
FSI ProjectSpin off
University of Rome Tor [email protected]
Example of 3D model for shells structure (3)Example of 3D model for shells structure (3)
Case 1:The curtain has the top edge constrained. It’s moved by the air flowentering from the window and subjected to its dead load.
FSI ProjectSpin off
University of Rome Tor [email protected]
Example of 3D model for shells structure (4)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 andit’s free to fall because the top edge constraint is missing.
FSI ProjectSpin off
University of Rome Tor [email protected]
Example of related areasExample of related areas
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.
Hemodynamics and FSI Fluid-Structure InteractionHemodynamics and FSI Fluid-Structure Interaction
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
HW & SW configurationHW & SW configuration
FSI ProjectSpin off
University of Rome Tor [email protected]
Example of hemodynamics problem (1)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 ProjectSpin off
University of Rome Tor [email protected]
Example of hemodynamics problem (2)Example of hemodynamics problem (2)
SHUNT
FSI ProjectSpin off
University of Rome Tor [email protected]
ContactContact
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