Fluid-Structure Int Fluid-Structure Interaction in S raction in - - PowerPoint PPT Presentation
Fluid-Structure Int Fluid-Structure Interaction in S raction in STAR-CCM+ AR-CCM+ Alan Mueller Alan Mueller CD-adapco CD-adapco What is FSI? What is FSI? Air Air Int Interaction with a raction with a Fle Flexible ible Structure
Fluid-Structure Int Fluid-Structure Interaction in S raction in STAR-CCM+ AR-CCM+ Alan Mueller Alan Mueller CD-adapco CD-adapco
What is FSI? What is FSI?
Air Air Int Interaction with a raction with a Fle Flexible ible Structure Structure
What is FSI? What is FSI?
Water/Air Int r/Air Interaction with a raction with a Structure Structure Courtesy Germanischer Lloyd Courtesy CFD Marine
What is FSI? What is FSI?
Vortex Induced Vibration and Induced Vibration and Galloping Galloping
What is FSI? What is FSI?
Aeroelastic Flutt elastic Flutter
What is FSI? What is FSI?
Hydr Hydroplaning
What is FSI? What is FSI?
Gulping Gulping Courtesy Tetra Pak
What is FSI? What is FSI?
Ask 20 Ask 20 engineer engineers “ s “What is hat is FSI?” and FSI?” and you will lik u will likely ge ly get 20 t 20 dif different answ erent answers ers There There is is no not t sim simply one ly one appr approach v
lid for all FSI pr r all FSI proble
ms The anal e analyst must be yst must be present presented with ed with a a range of options and range of options and chose the most chose the most suitable suitable
The Uniq The Unique Challenges of FSI Simulations ue Challenges of FSI Simulations
Pr Protocols and
rmats for e r exchanging data changing data – Getting data from Code A to Code B Mapping data Mapping data be betw tween n non-conf non-conformal
meshes – Finding neighbors and interpolating Coupling methods Coupling methods – Algorithms for accuracy, stability, efficiency Dynamic fluid mesh Dynamic fluid mesh evolution
– Topology changes in the fluid domain Validat lidation of FSI result
9
VOF f F for free sur r free surface trans ace transient flo ent flow Ov Over erse set meshes f t meshes for motion and def r motion and deformation rmation Fluid int Fluid interaction with eraction with
– multi-body rigid structures – compliant structures
Co-Simulation betw Co-Simulation between dif een different CAE codes erent CAE codes Mapping be Mapping betw tween non-conf een non-conformal meshes rmal meshes Parallel scalability on com Parallel scalability on comput ute clust e cluster Enabling t Enabling technologies t chnologies to mee meet the challenges the challenges
Simulation of St Simulation of Store Separation
DFBI – DFBI – Fluid int luid interaction with a raction with a Rigid Body Rigid Body Ov Over erse set T t Technology chnology
Simulation of Lif Simulation of Lifeboat Launching boat Launching
Overset grids allow simulation of launching
(lifeboats, missiles etc.). VOF f F for free sur r free surface transient flo ace transient flow DFBI – DFBI – Fluid int luid interaction with a raction with a Rigid Body Rigid Body Ov Over erse set T t Technology chnology
The Challenges of FSI The Challenges of FSI
The 3 st The 3 steps of “Mapping” eps of “Mapping”
Sear Searchi ching f g for opposin r opposing neighbors neighbors
– Most of the computer time
Int Interpolating sour
ce stencil data on a target point encil data on a target point
– Source and targets may be face or vertex
Ofte ten r requires i inte tegration ( (quadratures) – intensive extensive variables – pressure force – heat flux heat – FEA nodal loads: integration of intensive variables against the shape function.
Neighbor Sear Neighbor Search Im ch Imperativ perative
Sear Search req ch requires little user int ires little user intervention ention The sear The search e ch excludes po cludes potential neighbors ntial neighbors based on pr based on proximity and orientation imity and orientation Critically im Critically impor portant f ant for shee r sheet me t metal par tal parts
– resolve ambiguities of poor geometry – thin solid parts may be on the wrong side of the fluid surface
Parallel rallel Mapping is a must! Mapping is a must!
– Takes advantage of distributed memory
Courtesy of Daimler
Mapping Displacement f Mapping Displacement for Lo r Low Y+ meshes w Y+ meshes
C0 continuous mapping very important for low y+ meshes Otherwise very easy for morpher to invert high aspect ratio cells in prism layer
Inconsist Inconsistent Geome nt Geometric R ric Representations presentations
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 The Challenges of FSI
18 18
Me Methods f thods for Ex r Exchanging changing Data S Data STAR AR-CCM+/CAE
File Based T File Based Transf ansfer: Im er: Impor port/Map/Expor /Map/Export
– Data exchange via files on a hard-disk – CAE code need not be resident in memory – Often called “Loose Coupling” – User responsible for exchange synchronization
Sock Socket Based T et Based Transf ansfer: er: Co-Simulation API 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
STAR-CCM+ : Loosely Coupled CAE Suppor AR-CCM+ : Loosely Coupled CAE Support
Im Impor port CAE Mesh: CAE Mesh:
– Abaqus, Nastran, Ansys, STAR-CCM+ – RadTherm, es-ice
Map Map & Expor & Export R Results t sults to CAE CAE
– Surface Loads
– Volume Loads
Im Impor port & Map FEA R & Map FEA Results sults
– Temperature Fluid Wall BC – Displacement, Eigenmodes Morpher
import from/export to the native CAE format Display mapped results on imported mesh
STAR AR-CCM+ can
provide an ide an im impor port/map/e /map/expor xport ser t service as ice as a a po powerful ul com complement t lement to HEEDS HEEDS
Heeds: W Heeds: Workflo rkflow Pr Process Contr
CAD Geometry
NX
Nonlinear Crash
LS‐Dyna
NVH Analysis
Nastran
Meshing & Morphing
Hypermesh SHERPA
22 22
Abaq aqus/S us/STAR-CCM+ Co-Simulation CCM+ Co-Simulation
Coupling via A Coupling via Abaq aqus us Co-Simulation API of SIMULIA Co-Simulation API of SIMULIA – Manages Coupling Synchronization/Exchange/Mapping – Abaqus v6.13/STAR-CCM+ v8.04+ (implicit coupling) – Surface to Surface Mapping STAR AR-CCM+
Abaq aqus us (e (explicit xplicit or
standard) – Pressure – Shear traction – Surface HTC, Tref Aba Abaqus us STAR-CCM+ AR-CCM+ – Displacement, velocity – Temperature
Overset Ball and Socket Stop Valve Hydroplaning
Strat Strategy : gy : Couple S Couple STAR AR-CCM+
Abaqus us
– Implicit Coupled on workstation
STAR AR-CCM+ V
Induced Flow ar around Fle
ible Pipe Abaq aqus FEA us FEA for Fle r Flexible Pipe ible Pipe
Fle Flexib ible riser le riser (L/D (L/D = = 50) in turbul 50) in turbulent cr nt crossflo
Riser cross section Riser cross section
Riser dimensions: Riser dimensions:
L = 3.8125 m, D = 76.25 mm T = 7.05 mm
Current: Current:
Vin = 1.2 m/s Re(D) = 81700 Structural ctural Material P Material Properties:
Young’s Modulus= 1.5 GPa; Poisson ratio = 0.42; density = 8563 kg/m3;
Coupled Solution : Displacement and V Coupled Solution : Displacement and Vorticity icity
z/L=0.25 L=0.25 z/ z/L= L=0.5
The Challenges of FSI The Challenges of FSI
Degrees of Coupling Degrees of Coupling
Two-w
y coupling for fluid-elastic eq r fluid-elastic equilibrium uilibrium
– Steady-state flow over static structure deformed by fluid loads
One-w One-way dynamic coupling y dynamic coupling
– Loads only go from fluid to structure – Loads only go from structure to fluid
Two-w
y dynamic coupling
– Explicit (exchange loads once per time step)
incompressible fluid
– Implicit (exchange loads more than once per time step)
The Challenges of FSI The Challenges of FSI
Experimental V Experimental Validation: W lidation: Wedge Dr dge Drop In W
Com Comparison of Experiments and arison of Experiments and Models Models Peterson, W
man, and Frank: “ ank: “Drop T Drop Tests t s to Suppor Support W Water-Im Impact and pact and Planing Planing Boat Dynamics Theor Boat Dynamics Theory”, Dahlgren Division ”, Dahlgren Division Na Naval Sur l Surface W ace Warfare are Cent Center er, CSS/TR , CSS/TR-9
7/25 STAR-CCM+ V AR-CCM+ VOF with dif F with different bodies erent bodies
– Rigid Body (6DOF, DFBI) – Elastic Body (FV stress) – Elastic Body (Abaqus Co-Simulation) – Elastic Body (FE Stress)
We Wedge D Drop I In Wa Water
Vertical acceleration Angular acceleration (rad/s2) Equivalent Stress (MPa) All Methods give good agreement to experiments
AeroElastic Elastic Prediction W rediction Workshop: HIRENASD rkshop: HIRENASD
2.3M cells 2.3M cells 53K nodes 53K nodes
Aerodynamic Eq dynamic Equilibrium uilibrium at dif at different A erent AOA Static Structur Static Structure, St e, Steady air eady airflo low at def w at deformed shape rmed shape Ma=0.8, R Ma=0.8, Re=23.5x1 =23.5x106, q/E=0.48x1 , q/E=0.48x10-6
Wing Tip Displacement Lift Coefficient
Windof Windoff Vibration Modes : A ibration Modes : Abaq aqus us vs vs Experiment Experiment
f=25.55 Hz ( f=25.55 Hz (26.25 26.25) f=80.25 Hz ( f=80.25 Hz (78.20 78.20) f=106.20 Hz f=106.20 Hz f=160.35 Hz f=160.35 Hz (165.25 165.25)
NASA FUN3D NASA FUN3D
Aeroelastic Equilibrium Cp: AOA 2
STAR-CCM+/Abaqus STAR-CCM+/Abaqus
x/c x/c
Aeroelastic Aeroelastic Equilibrium quilibrium Cp: AOA 2, near wing tip
STAR-CCM+/Abaqus STAR-CCM+/Abaqus NASA FUN3D NASA FUN3D
Fluid-Elastic Instabilities in a Fluid-Elastic Instabilities in a Tube Bundle be Bundle Weaver & A er & Abd-Rabbo. A d-Rabbo. A Flo Flow Visu Visuali alizati ation Study of a
Square uare Arra Array of T y of Tubes in W bes in Water Cr r Crossflo
Journal of Fluids Fluids Engineeri
ember ber 1
7, p. 354-363.
Fluid-Elastic Instabilities in a Fluid-Elastic Instabilities in a Tube Bundle be Bundle
Vorticity ticity Vu=0.25m/s Vu=0.31m/s
STAR-CCM+ De AR-CCM+ Development Directions lopment Directions
– Introduce and couple more physics within STAR-CCM+ – Allow for co-simulation with a multiple of CAE solvers
FEA Models Intr FEA Models Introduced
– 3D continuum, shells, and beams – 6 DOF Beam to/from Fluid Wall Surface Mapping
STAR-CCM+ Co-simulation API AR-CCM+ Co-simulation API
– Coupling to CAE Vendor Codes – Coupling to In-house Codes
Future De ture Developments in lopments in STAR AR-CCM+
Man Many FSI challenges FSI challenges Demonstr Demonstrat ated industr ed industrial “strength” e ial “strength” exam amples of S ples of STAR AR-CCM+
The k The key enablers of the t y enablers of the technology are chnology 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 Conclusions
Thank Y Thank You F u For Y r Your A ur Attention ntion