rapid design and flow simulations for turbocharger …...icem-cfd tetra/prism, hexa, ......

EASC ANSYS Conference 2009

RAPID DESIGN AND FLOW SIMULATIONS FOR

TUBOCHARGER COMPONENTS

Authors

Dipl.-Ing. Jonas Belz CFDnetwork® Engineering

Dipl.-Ing. Ralph-Peter Müller CFturbo® Software & Engineering GmbH

www.cfturbo.de www.cfdnetwork.de

Rapid Design and Flow Simulations for Turbocharger Components

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Content

Introduction 03

Design Process and Meshing 04

Performance Prediction Strategy 14

Compressor Example 16

Summary and Prospects 20

Rapid Design and Flow Simulations for Turbocharger Components

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General Design Process

Dimensioning,

Design

CFturbo®

Grid generation

ICEM-CFD Tetra/Prism,

HEXA, TurboGrid, …

CAD

Catia, SolidWorks,

UG NX, ProE, …

Production Optimization:

interactive or automated

CFD/FEM Simulation

ANSYS-CFX, Fluent

Measurement

Rapid Prototyping,

Validation

Rapid Design and Flow Simulations for Turbocharger Components

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Demonstration Case

Compressor Impeller Design Point:

Mass Flow = 0.285 kg/s

Ptot = 2.25

Speed = 70.000 rpm

• Main Dimensions

• Meridional Contour

• Blade Design

• Volute Design

Stage Design

Rapid Design and Flow Simulations for Turbocharger Components

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Fluid Data, Design Point, Parameters to determine Main Dimensions Main Dimensions

Conceptual Design CFturbo® – Example: Compressor Impeller 1

Rapid Design and Flow Simulations for Turbocharger Components

Shape Hub & Shroud, Leading/Trailing Edge Position Meridional Contour

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1 Conceptual Design CFturbo® – Example: Compressor Impeller

Hub

Shroud

LEMain

TE

LESplitter

Rapid Design and Flow Simulations for Turbocharger Components

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Blade Form, Velocity Triangle, Leading/Trailing Edge Angle Blade Properties

1 Conceptual Design CFturbo® – Example: Compressor Impeller

b2

b1

Rapid Design and Flow Simulations for Turbocharger Components

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1

Blade Angle Distribution, Wrap Angle, Blade Manipulation Mean Lines

Conceptual Design CFturbo® – Example: Compressor Impeller

m m

q

Conformal

Representation

of Blade Angles

q

m

Rapid Design and Flow Simulations for Turbocharger Components

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Thickness distribution, leading/trailing edge shape definition Blade Profiles

1 Conceptual Design CFturbo® – Example: Compressor Impeller

Rapid Design and Flow Simulations for Turbocharger Components

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Complete Design containing Impeller and Volute Stage Design

1 Conceptual Design Cfturbo®

Rapid Design and Flow Simulations for Turbocharger Components

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2 2 Pre-Processing

Preparation of Model and Geometry Direct Export to ICEM CFD

Rapid Design and Flow Simulations for Turbocharger Components

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Meshing Parameters Dialog Meshing ICEM CFD

2 2 Pre-Processing

• Automated, script-based meshing

• Complete parameter setup in CFturbo®

Rapid Design and Flow Simulations for Turbocharger Components

Tetra/Prism Hexa

(automated) (manual)

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Tetra Mesh with Prism Layers / Hexa Mesh Meshing

2 2 Pre-Processing

Design and meshing for whole

compressor/turbine stage

takes less than 1 hour

Script-based impeller

meshing (ICEM Hexa and

TurboGrid) in development

Rapid Design and Flow Simulations for Turbocharger Components

Total Pressure,

Temperature

Static Pressure

Steady Simulation

Frozen Rotor

Turbulence Model: SST

Simulation Setup

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Goals

• Fast performance prediction

• As many runs as necessary, as

few as possible!

• Comparing two or more designs

• Pressure Ratio

• Efficiency

• Range

Goal, Model, Boundary Conditions Simulation Setup

Simulation 3

Rapid Design and Flow Simulations for Turbocharger Components

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Pts = 1.48

Ptot Inlet = 101325 Pa

→ Pstat Outlet = 150kPa

Determine Boundary Conditions Simulation Strategy

Simulation 3

Pts = 1.48

Simulation Strategy CFturbo’s performance prediction

Possible Unstable

Region

Pstat Outlet = 150kPa

Rapid Design and Flow Simulations for Turbocharger Components

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Post-Processing 4

Pressure Distribution, Velocity Results

Simulated Cases

Three Impellers, One Volute

1. Impeller without Tip Clearance

2. Impeller with 0.2 mm Tip

clearance

3. Impeller with 0.4 mm Tip

clearance

Hub

Shroud

Tip Clearance

Span

Impeller

Rapid Design and Flow Simulations for Turbocharger Components

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Post-Processing 4

Tip Vortex in Impeller Tip Clearance Influence

0.2 mm Tip Clearance 0.4 mm Tip Clearance

Rapid Design and Flow Simulations for Turbocharger Components

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Post-Processing 4

Differences in Mach Number Distribution Tip Clearance Influence

0.2 mm Tip Clearance 0.4 mm Tip Clearance No Tip Clearance

Mach Number

90% Span

Rapid Design and Flow Simulations for Turbocharger Components

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Post-Processing 4

Tip Clearance Influence, Results vs. Prediction Performance

No Tip Clearance

0.4 mm Tip Clearance

0.2 mm Tip Clearance

CFturbo Prediction

Design Point

Rapid Design and Flow Simulations for Turbocharger Components

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Summary and Prospects

► Parametric/semi-automatic design for radial and mixed flow turbomachines

► Stable process for performance prediction “in one go”

► Complete process is possible as one batch run

Rapid design process employing CFturbo® and ANSYS ® software

► CAE-Process Refinement by CFturbo® and CFDnetwork® Engineering

► Development of CFturbo® Software Package (New Release: Fall 2009)

Continuing…

CFDnetwork® Engineering