RAPID DESIGN AND FLOW SIMULATIONS FOR TUBOCHARGER COMPONENTS

Transcription

1 EASC ANSYS Conference 2009 RAPID DESIGN AND FLOW SIMULATIONS FOR TUBOCHARGER COMPONENTS Authors Dipl.-Ing. Jonas Belz Dipl.-Ing. Ralph-Peter Müller CFDnetwork Engineering CFturbo Software & Engineering GmbH

2 Content Introduction 03 Design Process and Meshing 04 Performance Prediction Strategy 14 Compressor Example 16 Summary and Prospects 20 Page 2

3 General Design Process Grid generation ICEM-CFD Tetra/Prism, HEXA, TurboGrid, CFD/FEM Simulation ANSYS-CFX, Fluent Dimensioning, Design CFturbo Optimization: interactive or automated Production CAD Catia, SolidWorks, UG NX, ProE, Measurement Rapid Prototyping, Validation Page 3

4 Demonstration Case Compressor Impeller Design Point: Mass Flow = kg/s Π tot = 2.25 Speed = rpm Main Dimensions Meridional Contour Blade Design Volute Design Stage Design Page 4

5 1 Conceptual Design CFturbo Example: Compressor Impeller Main Dimensions Fluid Data, Design Point, Parameters to determine Main Dimensions Page 5

6 1 Conceptual Design CFturbo Example: Compressor Impeller Meridional Contour Shape Hub & Shroud, Leading/Trailing Edge Position TE Shroud Hub LE Main LE Splitter Page 6

7 1 Conceptual Design CFturbo Example: Compressor Impeller Blade Properties Blade Form, Velocity Triangle, Leading/Trailing Edge Angle b 1 b 2 Page 7

8 1 Conceptual Design CFturbo Example: Compressor Impeller Mean Lines Blade Angle Distribution, Wrap Angle, Blade Manipulation m q Conformal Representation of Blade Angles m m q Page 8

9 1 Conceptual Design CFturbo Example: Compressor Impeller Blade Profiles Thickness distribution, leading/trailing edge shape definition Page 9

10 1 Conceptual Design Cfturbo Stage Design Complete Design containing Impeller and Volute Page 10

11 2 Pre-Processing Direct Export to ICEM CFD Preparation of Model and Geometry Page 11

12 2 Pre-Processing Meshing ICEM CFD Meshing Parameters Dialog Automated, script-based meshing Complete parameter setup in CFturbo Page 12

13 2 Pre-Processing Meshing Tetra Mesh with Prism Layers / Hexa Mesh Tetra/Prism (automated) Hexa (manual) Design and meshing for whole compressor/turbine stage takes less than 1 hour Script-based impeller meshing (ICEM Hexa and TurboGrid) in development Page 13

14 3 Simulation Simulation Setup Goal, Model, Boundary Conditions Simulation Setup Total Pressure, Temperature Goals Fast performance prediction As many runs as necessary, as few as possible! Comparing two or more designs Pressure Ratio Efficiency Range Steady Simulation Frozen Rotor Turbulence Model: SST Static Pressure Page 14

15 3 Simulation Simulation Strategy Determine Boundary Conditions CFturbo s performance prediction Simulation Strategy P stat Outlet = 150kPa Π ts = 1.48 Possible Unstable Region Π ts = 1.48 P tot Inlet = Pa P stat Outlet = 150kPa Page 15

16 4 Post-Processing 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 Pressure Distribution, Velocity Tip Clearance Shroud Span Hub Impeller Page 16

17 4 Post-Processing Tip Clearance Influence Tip Vortex in Impeller 0.2 mm Tip Clearance 0.4 mm Tip Clearance Page 17

18 4 Post-Processing Tip Clearance Influence Differences in Mach Number Distribution Mach Number 90% Span No Tip Clearance 0.2 mm Tip Clearance 0.4 mm Tip Clearance Page 18

19 4 Post-Processing Performance Tip Clearance Influence, Results vs. Prediction No Tip Clearance 0.2 mm Tip Clearance 0.4 mm Tip Clearance Design Point CFturbo Prediction Page 19

20 Summary and Prospects Rapid design process employing CFturbo and ANSYS software 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 CFDnetwork Engineering Continuing CAE-Process Refinement by CFturbo and CFDnetwork Engineering Development of CFturbo Software Package (New Release: Fall 2009) Page 20