Topology Optimization – Driven Design Development for Automotive Components

Ronald J. BanchakFE-DESIGN Optimization Inc., USA

Markus Stephan and Michael Böhm

FE-DESIGN GmbH Germany

Overview

• Short Introduction into Topology Optimization for CFD

– Basic Concepts

– Optimization Workflow

• Automotive Application Examples

– Automotive HVAC Flow Splitter

– Intercooler Intake Hose

– Exhaust Gas Recirculation Cooler

• Summary

Support

and

Coaching

Software-

Development

Engineering,

Services,

Customization

FE-DESIGN Your Partner for Structural and CFD optimization

FE-DESIGN combines development and engineering

of optimization methods

FE-DESIGN has the ability to deliver best solutions for

our customers, benefiting from many years of experience

Our customers improve their

optimization processes continuously due to

knowledge transfer with FE-DESIGN

Customers leverage FE-DESIGN´s knowledge,

with long-term business relationships

FE-DESIGN: Locations and ANSYS Partners

FE-DESIGN Optimization Inc

• Located in Des Plaines, IL (Chicago)

• An Affiliate of FE-DESIGN GmbH, Germany

• Dedicated to supporting our US customers

• Ron Banchak (General Manager), Mark Miller (Senior Technical Consultant)

FE-DESIGN Optimization Inc.

2700 South River Road, Suite 302

Des Plaines, IL 60018

info@fe-design.com

FE-DESIGN: Customers (extract)

CAD-Parameter based Optimization

• Optimization problem is based on a parameterized Geometry (CAD, Preprocessor, ...)

• Geometric Variation is achieved by reconstruction of an individual geometry based on a given set of parameters

• Geometry parameters are varied automatically within a given range (optional)

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Optimization problem has

to be parameterized

Restricted solution space

Comparative high

computational effort

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Topology Optimization

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• Optimization problem is based on the (meshed) available Design Space

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Topology Optimization

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• Optimization problem is based on the (meshed) available Design Space

• Geometric Variation is achieved by sedimenting individual cells

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Topology Optimization

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ssib

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• Optimization problem is based on the (meshed) available Design Space

• Geometric Variation is achieved by sedimenting individual cells

• An individual design proposal can be derived based on the collectivity of all free (= non-sedimented) cells

• General optimization schemes are not feasible

initia

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Redesign Rule: Elimination of local

backflow and recirculation by blocking out

of backflow areas

provides an “optimization” approach by

means of “improvement”

The Optimality Criterium is to avoid flow

recirculation

OC-based Topology Optimization

An achieved consequence is (for many

technical flows) a reduction of pressure

drop

Direct run time

communication with

the CFD solver

Only one single CFD

solver-run for complete

optimization process

suitable for large real world applications

Topology optimization with TOSCA Fluid

ANSYS Fluent

TOSCA Fluid Optimization

Time resp. Iteration

Optimization

and

Flow Result

Shared-Memory

Example Animation:

Current optimzation

solution during

convergence process

Topology optimization with TOSCA Fluid

TOSCA Fluid – Process Integration

• Result smoothing with TOSCA Fluid.smooth

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Topology OptimizationDerived Verification/

CAD model

Verification/CAD

Iso surface calculation, smoothing, data reduction

s m o o t h

surface model

(IGES, VRML, STL)

Topology Optimization driven Design DevelopmentExample: Intercooler Design

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Conventional Design Development

Package

Topology Optimization driven Design Development

Design

Iteration 2

Design

Iteration 1

Design

Iteration 3

Final

Design

Topo Opt

Proposal

Design

Recon.

Final

DesignPackage

Topology Opt

Additional

Constraints

6 to 10 Iterations in CAD

Parent Design,

KnowHow,

Intuition Analysis

…

Analysis Analysis

Analysis

Analysis

CADSTL

Application Example 1:Automotive HVAC Flow Splitter Manifold

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HVAC Flow Splitter Manifold (generic)

Behr GmbH & Co. KG

HVAC Flow SplitterDesign Space, physical models and Bound.Cond.

Dimensions = (0,2 x

0,14 x 0,12) m3

Fluid = AIR

Objective: Design

Proposal with low

pressure drop

Standard Duct

and available

Design Space

HVAC Flow SplitterResults: Optimized Geometry (Design Proposal)

Original Part Optimized Design Proposal

HVAC Flow SplitterResults: Optimized Geometry, Pathline and Pressure Drop at 5 m/s

20

Design Space

Optimized Design Proposalrel. mean Total Pressure Drop

Std Opt

-26,1%

p 26 %

Application Example 2:CFD Topology Optimization of an existing Intercooler Intake Hose

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Introduction

Turbocharger System

Introduction

Inital Design Proposal

Pathlines (colored with velocity magnitude)

Flow Performance of the Inital Design Proposal

Contours of Total Pressure Gradient (Magnitude), pa/m

dissipative flow separation and

recirculation zones

| grad ptot |

exemplary local flow

separation

Optimization Results (1)Sedimented Zones

Result Analysis: Geometry

Inital Design optimized Design

Result Analysis: Pathlines (detail) (coloured with Velocity Magnitude)

Inital Design optimized Design

Result Analysis: Total Pressure DropComparison of the Total Pressure Drop

100%

79.6%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

rela

tive T

ota

l P

ressure

Dro

p

Initial Design Optimized Design

-20,4%

Application Example 3:Exhaust Gas Recirculation Cooler

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EGR Cooler

Exhaust Gas Recirculation Systems NOx-Abatement for internal combustion engines

Functional diagramm

Example Assembly

EGR CoolerResults for existing Designs

“Standarddesign 1”

ptot = 9,5 pa

Uniformity Index = 0,81

Contours of Normal Velocity Magnitude at Outlet, m/s

EGR CoolerDesign Space and Model settings

Boundary Conditions:

Inflow = PRESSURE

Outflow = INLET, wout = -3 m/s

Fluid AIR

Isothermal, turbulent, stationary,

incompressibel

= 1.81 · 10-5 kg/(m·s)

= 1.205 kg/m3

available

design space

available

design space

EGR CoolerResults: Optimized Design Proposal

EGR Cooler: Comparison of DesignsCross sectional velocity uniformity and heat exchanger efficiency

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Std 1 Std 2 Ver 1

Designvariante

0,54

rela

tive

To

tal P

ressu

re D

rop

rela

tive

Exch

an

ge

r E

ffic

ien

cy

0,67

1,0

0,66

0,87

0,96

Transfer Efficiency

+11% resp. + 45%

Pressure Drop

- 19% resp. - 46 %

Optimized Design ProposalStandard2Standard1

Summary

• Topology Optimization of interior flow domains using Optimality Criteria Methods

• Possible Optimization Objectives are

– Reduction of total pressure drop

– Homogenization of cross section velocity distribution

– and more…

• Only one single CFD solver-run for a complete optimization process is needed

• Significantly faster than traditional automatic Optimization Procedures like CAD-parameters, Morphing etc.

• Giant solution space Innovation!

• Actual available for ANSYS FLUENT Ver. 14

Appendix

39

40

Design Space

Topology optimization with TOSCA Fluid

• Define the Design

Space (e.g. CAD)

Outflow 1

Outflow 2

Inflow

• Define your

Boundary

Conditions

• Run the

Optimization

• Meshing “as usual”

41

Topology optimization with TOSCA Fluid

Design Space

Outflow 1

Outflow 2

Inflow

Optimized Channel

Shape

Prevented Flow

Free Flow

Transition Area

(defining new channel shape)