Computation Fluid Dynamics – ANSYS Software Key Features
and Best Practices
Dr. Wim Slagter Lead Product Manager, ANSYS, Inc.
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ANSYS, the company • ANSYS design, develops, markets
and globally supports a comprehensive range of engineering simulation software
• Proven software technologies for o Fluid Dynamics o Structural Mechanics o Acoustics o Electromagnetics o Multiphysics
• Specialized tools, incl. o ANSYS Icepak (thermal/flow
for electronics) o ANSYS nCode DesignLife (for
fatigue) • World’s largest pool of experts
providing CFD Best Practices
Emag
Acoustics
Structural
CAD Import
Parametric Simulation
Design Exploration
Meshing
Post-processing
Fluid
ANSYS – addressing your current & future CFD challenges
Transient or steady-state Laminar and turbulent flows
Heat transfer
Buoyant flows
Incompressible / compressible
Multi-component flows, multi-phase Real gas modeling
Filters/porous regions Reactions and combustion
Moving geometry and mesh
Rotating machinery
Solution-based adaptive remeshing
1-way and 2-way Fluid-Structure Interaction Courtesy of GE Energy
Courtesy of BMW AG
Key Enablers: • Links to almost any CAD system • Parametric, persistent process • Simulation focused: allows
engineers to do simulation driven product development
• Direct modeling allows for re-animating dumb CAD (geometry without parameters) models
• Extensive modeling solutions
Engineering Productivity: Geometry Modeling Bi-directional CAD connections
Feature-Based Modeling
Direct Modeling
CAD Neutral: Direct and Feature-Based Modeling!
Setup Wizards
Engineering Productivity: Workflow
Geometry
Meshing
Problem Setup
Post Processing Customized Menus
Increased Productivity through Automation and Customization!
• Advanced physical models • High-performance solvers
Engineering Productivity: Accuracy & Speed
User-defined LES for highest accuracy; RANS for all other areas
RANS
LES Re=395
New steady-state scheme as accurate as transient Wigley hull simulation
Free surface profiles • Steady-state scheme • Transient scheme • Experiment
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Cavitation number
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Hofmann et al [20]CFD
Recondisation simulation Cavitating flow in a centrifugal pump can also be modeled in steady state
Get reliable answers faster, without compromise on flow physics!
Integrated Design Exploration & Optimization
Tradeoff Chart
Parametric CAD model
Response Surface and Sensitivity Chart
Section Length
Guide Curve Angle
Guide Curve
Radius
Effe
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Section Length
DOE generated with Design Points Guide Curve
Angle (Deg)
Guide Curve Radius
(mm)
Section Length (mm)
EFA (mm2)
Baseline 63 41 51 1100.2
Optimized 50 30 60.5 1180.4
Baseline Design Optimized Design
Gain deep insights necessary to optimize product performance, and
produce better products faster!
Drag sensitivity
Downforce sensitivity
Total pressure drop sensitivity
Total pressure drop sensitivity
Estimated downforce improvement = 41.6N Actual downforce improvement = 39.1N
Adjoint flow solver: • An understanding of the shape sensitivities with respect to design variables
in a single computation! • A quantitative performance estimate due to a design change without the
need to simulate the actual change!
Adjoint is a very efficient means of quickly exploring a design space with thousands degrees of design freedom!
Shape Sensitivities wrt Design Variables
Fluid Flow
Thermal Stress
Fluid-Structure Interaction Rigid Body FSI 1-way FSI 2-way FSI
Deformation
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Comprehensive suite of FSI capabilities for accurate prediction of
a broad range of design scenarios
• Design objective: o Maximize amplification ratio for a given size and power consumption o 3 main design parameters, i.e. gap in annular ring, internal profile of ring,
profile of external ramp • Customer benefits include:
o Explored 10-fold of design variations than would otherwise have been possible (each day 10 instead of 1)
o Improved performance 250% over original design
Customer Example: Dyson Air Multiplier™ Fan
Courtesy of Dyson
• Design objective: o To optimize the dual-outlet exhaust manifold for robust performance o 4 main design parameters, i.e. outlet diameter of the manifold, thickness
at inlet, external temperature, engine RPM • Design constraint:
o Maximum displacement should not exceed 1.5 mm!
Customer Example: Exhaust Manifold
Fluid Flow
Deformation
Von Mises Stress
Temperature
• Design objective: o To optimize the dual-outlet exhaust manifold for robust performance o 4 main design parameters, i.e. outlet diameter of the manifold, thickness
at inlet, external temperature, engine RPM • Design constraint:
o Maximum displacement should not exceed 1.5 mm!
Customer Example: Exhaust Manifold
Fluid Flow
Deformation
Von Mises Stress
Temperature
All samples report maximum deformation below 1.5 mm
Effect of engine speed and thickness at outlet on maximum deformation