Fluid-Structure Interaction in STAR- CCM+ Alan Mueller CD-adapco - - PowerPoint PPT Presentation
Fluid-Structure Interaction in STAR- CCM+ Alan Mueller CD-adapco Outline Present STAR-CCM+ examples of FSI in different industries Review the challenges of FSI Examine key STAR-CCM+ technologies to enable industrial strength FSI A peek of
Fluid-Structure Interaction in STAR- CCM+ Alan Mueller CD-adapco
Present STAR-CCM+ examples of FSI in different industries Review the challenges of FSI Examine key STAR-CCM+ technologies to enable industrial strength FSI A peek of what’s on the horizon in STAR-CCM+
Outline
Fan Blade interaction in Air
Ground Transportation
Abaqus STAR-CCM+
Marine
Water/Air Interaction with a Flexible Structure
Off-Shore, Oil & Gas
Riser Vortex Induced Vibration and Galloping
Jumper VIV with Internal VOF Flow
Subsea Equipment , Oil & Gas
Def.: U (x200); Field: VM stress Inlet
Aerospace
Aeroelastic Flutter
Food Packaging
Pouring and Gulping Courtesy Tetra Pak
BioMedical
Heart Valve
– Blood flow interaction with hyperelastic material
What is FSI?
Ask 20 engineers “What is FSI?” and you will likely get 20 different answers There is not simply one approach valid for all FSI problems The analyst must be presented with a range of options and chose the most suitable
The Unique Challenges of FSI Simulations
Protocols and formats for exchanging data – Getting data from Code A to Code B Mapping data between non-conformal meshes – Finding neighbors and interpolating Coupling methods – Algorithms for accuracy, stability, efficiency Dynamic fluid mesh evolution – Topology changes in the fluid domain Validation of FSI results 11 11
The Challenges of FSI
The 3 steps of “Mapping”
Searching for opposing neighbors
– Most of the computer time – Robust for less than perfect meshes
Interpolating source stencil data on a target point
– Source and targets may be face or vertex – Strive for accuracy, conservation, boundedness
Often requires integration (quadratures) – intensive extensive variables – pressure force – heat flux heat – FEA nodal loads: applicable to higher order elements.
Inconsistent Geometric Representations
FEA VIEW of a WING CFD VIEW of a WING
Beam to Surface Mapping
?
Shells(no mass,stiffness) Beam elements Kinematic Couples
The Challenges of FSI
Simulation of Store Separation
DFBI – Fluid interaction with a Rigid Body Overset Technology
Overset and Deforming Bodies
Abaqus Co-simulation Overset Technology Morphing Technology
Ball and Socket Stop Valve Overset + Morphing
The Challenges of FSI
18 18
Methods for Exchanging Data STAR-CCM+/CAE File Based Transfer: Import/Map/Export
– Data exchange via files on a hard-disk – CAE code need not be resident in memory – Often called “Loose Coupling” – Exchange managed by HEEDS
Socket Based Transfer: Co-Simulation API – API controls exchange synchronization – Data exchanged via sockets
– CAE code and STAR-CCM+ both executing in memory
–GT Power, Wave, Olga, AMESim, Relap5
The Challenges of FSI
Degrees of Coupling
Two-way coupling for fluid-elastic equilibrium
– Steady-state flow over static structure deformed by fluid loads
One-way dynamic coupling
– Loads only go from fluid to structure – Loads only go from structure to fluid
Two-way dynamic coupling
– Explicit (exchange loads once per time step)
incompressible fluid
scales
– Implicit (exchange loads more than once per time step)
The Challenges of FSI
Experimental Validation: Wedge Drop In Water
Comparison of Experiments and Models Peterson, Wyman, and Frank: “Drop Tests to Support Water- Impact and Planing Boat Dynamics Theory”, Dahlgren Division Naval Surface Warfare Center, CSS/TR-97/25 STAR-CCM+ VOF with different bodies
– Rigid Body (6DOF, DFBI) – Elastic Body (FV stress) – Elastic Body (Abaqus Co-Simulation) – Elastic Body (FE Stress)
Wedge Drop In Water
Vertical acceleration Angular acceleration (rad/s2) All Methods give good agreement to experiments
AeroElastic Prediction Workshop: HIRENASD
2.3M M cells lls 53K K node des
Windoff Vibration Modes : Abaqus vs Experiment
f=25. 5.55 55 Hz (26.25 6.25) f=80. 0.25 25 Hz (78.20 8.20) f=106.20 06.20 Hz f=160.35 60.35 Hz (165 65.25 25)
Aerodynamic Equilibrium at different AOA Static Structure, Steady airflow at deformed shape Ma=0.8, Re=23.5x106, q/E=0.48x10-6
Wing Tip Displacement Lift Coefficient
x/c
Aeroel elastic stic Equil ilibr ibrium ium Cp: AOA 2, near wing tip
ST STAR AR-CC CCM+/ +/Abaqu baqus NAS ASA A FUN3D N3D
Fluid-Elastic Instabilities in a Tube Bundle Weaver & Abd-Rabbo. A Flow Visualization Study of a Square Array of Tubes in Water Crossflow. Journal of Fluids Engineering. September 1985. Vol. 107, p. 354- 363.
Fluid-Elastic Instabilities in a Tube Bundle
No other commercial, in-house, or academic code has reproduced this instability ! Vu=0.25m/s Vu=0.31m/s Vorticity
Introduce and couple more physics within STAR- CCM+ Allow for co-simulation with a variety of CAE solvers
Development Trends in STAR-CCM+
Courtesy Germanischer Lloyd
Introducing DFBI Wall Contact Forces
DFBI – Fluid interaction with a Rigid Body Overset Technology Contact Forces between moving rigid body with rigid walls
3D solids, shells, and beams
– Elastic Material, Non-linear Geometry – Constraints and Loads
Fluid/Solid Interfaces for FSI
– Solid boundary to fluid boundary – Beam to fluid boundary
Introducing FEA Structural Models
Flow within a vibrating pipe modeled as a beam Thermal Stresses with CHT Dynamic with Non-Linear Geometry
A library of functions and headers that can be called from an external code to enable communication with the STAR-CCM+ server
– Coupling to In-house codes – Coupling to CAE vendor codes
STAR-CCM+ Co-simulation API
STAR-CCM+ External Code
Many FSI challenges have been successfully addressed Demonstrated industrial “strength” examples of STAR-CCM+ The key enablers of the technology are
– VOF for free surface transient flow – Overset Technology for motion and deformation – Fluid interaction with
– Mapping between non-conformal meshes – Co-Simulation Application Program Interface – Parallel scalability on compute clusters
Conclusions
Thank You For Your Attention