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
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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
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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