ansys cfd v17 update seminar - caeai.com
TRANSCRIPT
ANSYS CFD v17
Update Seminar
2www.caeai.com
Outline
ANSYS CFD Demo
— System coupling : CFX and Mechanical
— Live CFX Solution Monitoring
ANSYS CFX v17
ANSYS Fluent v17
ANSYS Icepak v17
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CFX System Coupling demo
Flow inlet
Flow outlet
Fixed support
FSI interface
Fixed support
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Outline
ANSYS CFD Demo
— System coupling : CFX and Mechanical
— Live CFX Solution Monitoring
ANSYS CFX v17
ANSYS Fluent v17
ANSYS Icepak v17
5www.caeai.com
2-Way FSI between CFX and Mechanical
— Supersede MFX with workflow and technology consistent with
Fluent-Mechanical coupling
— Initial support for steady and transient exchange of forces and
resultant displacements
FSI with CFX and Systems Coupling
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Continuously driving down
simulation times!
Special focus on Transient
Rotor-Stator
Multiple areas improved
— Assembly/discretization
— Linear solver
— GGI intersection
— …
CFX HPC Performance
Overall impact of efficiency improvements over multiple
releases, shown on example transient water turbine simulation
with 40M nodes (benchmark case in collaboration with Voith
Hydro and HLRS in Stuttgart)
R15
R16
R17
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Improved Solver I/O Efficiency
• Drastically reduced solver I/O for
large/complex cases with very large
number of regions/face sets (10s of
thousands) when running parallel
— Previously could become large enough
to impact overall solution time
— Activated automatically
• No additional setting required
Reduction in wall clock
seconds for I/O on an
example test case with
many regions
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• New Shielded Detached Eddy Simulation
(SDES) and Stress-Blended Eddy
Simulation (SBES)
— Faster switch to LES modes
— Combine RANS and LES with blending
Blended eddy viscosity
• Intermittency Transition Model
— Full release in CFX
• All turbulence model enhancements also
released in Fluent
Advances in Turbulence Modelling
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Significantly improved HPC scalability
in speed of Monte Carlo solver
CFX Monte Carlo Radiation Model Scalability
Complex headlamp test case with 10E6 historiesComparison when solving only radiation and energyDramatically better solver speed scalability for
simulations with the Monte Carlo radiation model
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BladeModeler: Blade Row Geometry
•
— Support in BladeGen and BladeEditor
• Provides connection between BladeEditor and BladeGen
• BladeEditor CADImport feature directly creates NDF file for
loading into BladeGen
— Future :
• Support broader BladeGen to BladeEditor workflow and
parameters
• Provide improved connection to third party blade design
tools
CADBladeEditorCADImport
BladeGen
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Turbo Blade Row Modeling
•
— Time Transformation and Fourier Transformation
• Multi-stage, Asymmetric flow, Multi-disturbance
— Transient Blade Row with CHT
— Mixing plane improvements
— Convergence monitoring for cyclically periodic flow (β)
— Harmonic Analysis: frequency-domain method (β)
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Incorporation of numerous enhancements for challenging multi-
phase applications
— Volume weight averaging for turbulent dispersion coefficient (β)
• Better robustness of bubble boundary layers on fine meshes
— New root finder for wall superheating (β)
• Faster and more generic root finder for wall boiling applications
— Hosokawa model for wall lubrication force (β)
• Includes phase relative Reynolds number in liquid-gas bubble flows
— No clipping of interfacial area density for interphase mass
transfer (β)
• Greater accuracy where volume fractions 0
Enhanced CFX Multiphase Robustness
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Results output to arbitrary surface
locations
— Generate significantly less data
— Leaner simulation and analysis
Significant impact for large transient
cases
— Data (disk space) may be reduced by
orders of magnitude
— Less data sent between CFD-Post
engine and GUI during post-processing
Analogous capability for Fluent and CFX
User Surface Results Output for CFD-Post
Arbitrary surface output location (independent of solver mesh)
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• Ease-of-use for transient post-
processing
— ‘Music player’-like control
• Play/stop
• Next/previous time step
• First/last time step
— Options to
• Specify desired transient range
by time step, time, or crank angle
• Control which frame to use when
between available frames
• Save time animation to movie file
CFD-Post Time Animation
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Outline
ANSYS CFD Demo
— System coupling : CFX and Mechanical
— Live CFX Solution Monitoring
ANSYS CFX v17
ANSYS Fluent v17
ANSYS Icepak v17
16www.caeai.com
Fluent User Interface
Ribbon:Access primary workflow
Tree: Access model particulars and shortcuts
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Overset Mesh
Overset mesh problems can be set up and solved for:
• Steady and transient (fixed mesh), 3D and 2D planar
• Pressure Based coupled solver
• Incompressible density method
• Single-phase or VOF multiphase
• Heat transfer
• k-epsilon and SST k-ω turbulence models
• BETA: moving mesh, compressible flow, VOF with surface tension, pressure-far-
field BC, Workbench support, Pressure-Based segregated algorithms
Limitations:• DBNS not supported• Node-based gradients not supported
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Fluent Scalability
• Removed bottlenecks at case
reading and parallel build at high
core count runs
• Communication optimizations
• Benefits for large and small
cases
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
0 24,576 49,152 73,728 98,304 122,880 147,456
Spe
ed
up
NumCores
Combustor_830M on CRAY XC30
129,024 cores90% efficiencyNERSC Edison XC30 cluster
FlowEnergySpecies Transport
0
2000
4000
6000
8000
10000
12000
14000
0 1000 2000 3000 4000
Rat
ing
NumCores
Landing_gear_15m IB Haswell
15.0.7
16.0.0
17.0.0
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Additional benefits from combustion code refactoring for cases with
more than 1 cell zone with partially-premixed or PDF models
Example: In-Cylinder Combustion Performance
Ice_2m: 7 cell zones, 1.6 million cells
MDM, Spray, Partially premixed0.0
50.0
100.0
150.0
200.0
250.0
300.0
350.0
400.0
450.0
500.0
32 64 128 192 256 384
Solv
er R
atin
g
Number of Cores
2M-Cell In-Cylinder Combustion Case
15.0
16.0
17.0
55%
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Fluent Convergence Improvements
• Conservative Coarsening is now used by default with the coupled solver
– Typically improves convergence
– Especially helpful for cases with native polyhedral meshes and/or highly stretched cells.
– Can be disabled on the Multigrid tab of the Advanced Solution Controls dialog box
• Algebraic multigrid solver now automatically reorders the linear system
– Necessary to ensure proper ordering for multiple cell zones
– Can be disabled with (rpsetvar 'reorder/amg 0)
No reorderingNot converged >200 iterations
RCM reorderingConverged in 94 iterations
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Fluent Boundary Conditions
• Mass Flow Rate, Mass Flux, and Average Mass Flux are now defined according to the selected Reference Frame option in the boundary condition dialog box.
• Previously, these were always relative to the adjacent cell zone.
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Fluent Boundary Conditions (cont.)
• Backflow quantities at Pressure Outlets can now be defined
with respect to either the absolute reference frame or the
adjacent cell zone.
• Non-Reflecting Boundary Conditions can now be used with
compressible-liquid materials (beta)
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Fluent Profiles for Wall Translation/Rotation
• You can now specify a transient profile for wall
translation or rotation in the Wall Zone dialog box
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Adjoint Solver & Design Tool
• Compressible Flow support in adjoint solver
• Design tool Enhancements
• General bounding surfaces for deformations
• Prescribed motions (rotation, translation, scaling)
• Improved usability - constraint checking
• STL Export
Total pressure drop through a duct is
minimized by modifying the duct
geometry.
The duct is required to remain within
a complex bounding surface, defined
by an imported mesh, while the inlet
and outlet are fixed.
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Fluent Monte Carlo Radiation Model (beta)
Simple Lens Case using DO Model Simple Lens Case using Monte Carlo Model
• Re-application of CFX model
• Much better accuracy for collimated radiation compared with other
methods
• Especially useful for headlamp simulations, etc.
Limitations in R17.0
• Beta feature
• Serial-only
• 3D only
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Fluent DPM/DEM Enhancements
Rotation of DPM particles is now a full feature
— Gliding friction in particle-wall collisions and lift forces (Magnus lift) can
be included
— Applicable for particulate flows in cyclones, etc.
— Not compatible with MRF. Rotation not considered in O’Rourke
collision model
Additional DEM collision models
— Rolling friction: applicable to bulk solid flows (e.g. fluidized beds and
rotating drums)
— Hertzian
— Hertzian-dashpot
Macroscopic Particle Model UDF is now included with Fluent as an
Add-On model
New Rough Wall model gives better predictions in confined
geometries
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Wall Film Enhancements
Dry-splash regime Film-formation regime
• Eulerian wall-film model now supports variable density of the film material.
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Outline
ANSYS CFD Demo
— System coupling : CFX and Mechanical
— Live CFX Solution Monitoring
ANSYS CFX v17
ANSYS Fluent v17
ANSYS Icepak v17
29www.caeai.com
Icepak v17.0
IDX ECAD File Format now supported
— Similar functionality to IDF file format
— Contains component location, thermal properties, and component grouping
Trace and via conductivity mapping improvements
— Improved algorithm to compute the orthotropic thermal conductivity map
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Icepak v17.0
HPC scalability improvements
— Enhanced non-conformal interface handling
results in up to 50x speed up
— Fluid/solid load balancing enhancements
Full support for Remote Solve Manager
— Offload Icepak jobs to remote solve
machines
— WB integration means Icepak design points
can be solved through RSM
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Icepak v17.0
2D and 3D plotting of power maps
— Heatflux, Power and Temperature
variables supported
— Results can be viewed pre- and post-
solution
Export geometry to ANSYS SpaceClaim
— Icepak geometry can be exported in *.obj
format