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.

28www.caeai.com

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

30www.caeai.com

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