EVS28 KINTEX, Korea, May 3-6, 2015 Thermal Simulation of a Power Electronics Cold Plate with a Parametric Design Study Boris Marovic Mentor Graphics (Deutschland) GmbH, Germany, boris_marovic@mentor.com
Agenda I. Intention of This Work II. The Model Overlook III. The Project Definition IV. The Meshing Technology of FloEFD V. CAD embedded CFD of a Parametric CATIA V5 Model VI. Results of Parametric Study VII.Summary on What We ve Learned 2
Intention of This Work Demonstration of I. the usefulness of parametric CAD models II. the application of parametric studies for such models III. the efficiency of automated meshing in such cases IV. the efficiency of CAD embedded CFD for the design cycle 3
The Model Overlook IGBT module provided by: 4
The Model Overlook Solder Copper Silicon Chip Solder Copper Ceramic Base plate TIM 5
The Model Overlook Pin-Fin Thickness = Fin Thickness & Pin radius Pin-Fin Thickness = 1mm Fin length = 5mm Pin-Fin Thickness = 2mm Fin length = 15mm Pin-Fin Thickness = 1mm Fin length = 25mm Pin-Fin Thickness = 4mm Fin length = 25mm 6
The Model Overlook Parametric and equations for pin and fin spacing of the CATIA V5 model. 7
The Project Definition I. Triple IGBT module assembly on a cold plate design with fins and pins II. Cold plate material is Aluminum 6061 III. IV. Coolant is Water IGBT power is 690W (57,5W per IGBT chip) V. Diode power is 480W (40W per Diode chip) VI. IGBT modules consist of various materials VII. Local mesh on the IGBT module solids and region of the fins and pins 8
The Project Definition I. The Parametric Study Variables (used here): 1. Fin length (5, 15, 25mm) 2. Fin thickness (1, 2, 3, 4mm) 3. Spacing and pattern are defined by equations and will adopt II. Possible Further Parameter Variables 1. Flow rate (here: constant 1.0 l/s) 2. Coolant temperature (here: constant 20 C) 3. Coolant fluids (gases or liquids) (here: water) 4. Cold plate materials (here: Aluminum 6061) 5. Channel height, width and length (here: const. 10mm, 95mm, 200mm) 6. Pins instead of fins as well as other shapes 9
The Project Definition I. 1 st Project Setup: ~50 min II. Mesh size for finest fins: Fluid Cells 1,011,456 (5mm x 1mm) Solid Cells 682,501 Partial Cells 871,738 TOTAL 2,565,695 Meshing time: ~9 min 25 sec III. Mesh size for coarsest fins: Fluid Cells 27,540 (15mm x 4mm) Solid Cells 357,585 Partial Cells 216,832 TOTAL 601,957 Meshing time: ~1 min 15 sec 10
The Meshing Technology of FloEFD I. Cartesian mesh with octree refinement II. Immersed boundary layer type approach 1) III. Special wall functions and turbulence modelling 2) Solid Cell Partial Cell Fluid Cell 1) Advanced Immersed Boundary Cartesian Meshing Technology in FloEFD, Mentor Graphics, http://go.mentor.com/2gogl 2) Enhanced Turbulence Modelling in FloEFD, Mentor Graphics, http://go.mentor.com/2glzd 11
CAD embedded CFD of a Parametric CATIA V5 Model 12
CAD embedded CFD of a Parametric CATIA V5 Model 13
Results of Parametric Study 12 Overall configurations with 3 x 4 parameter variations Name Fin length [mm] Pin-Fin thickness [mm] Fluid Cells Solid Cells Partial Cells Total Cells Meshing time [s] Design Point 1 5 4 73,924 386,471 250,986 711,381 90 Design Point 2 15 4 27,540 357,585 216,832 601,957 75 Design Point 3 25 4 27,900 357,593 216,478 601,971 75 Design Point 4 5 3 97,646 390,519 262,808 750,973 95 Design Point 5 25 3 34,515 363,278 222,210 620,003 94 Design Point 6 15 3 34,674 363,175 222,378 620,227 86 Design Point 7 5 2 195,314 432,088 322,833 950,235 132 Design Point 8 25 2 82,309 405,471 270,676 758,456 113 Design Point 9 15 2 82,646 405,202 270,937 758,785 105 Design Point 10 5 1 1,011,456 682,501 871,738 2,565,695 565 Design Point 11 15 1 718,920 612,905 652,373 1,984,198 454 Design Point 12 25 1 642,986 595,872 609,358 1,848,216 289 14
Results of Parametric Study Smallest and largest Mesh Design Point 2-601,957 Design Point 10-2,565,695 15
Results of Parametric Study Velocity for hottest and coldest Design Point Design Point 3 Design Point 10 16
Results of Parametric Study Velocity and streamlines for hottest and coldest Design Point Design Point 3 Design Point 10 17
Results of Parametric Study Pressure for hottest and coldest Design Point Design Point 3 Design Point 10 18
Results of Parametric Study Fluid temperature for hottest and coldest Design Point Design Point 3 Design Point 10 19
Results of Parametric Study Surface Plot of the interior of the IGBT for hottest and coldest De sign Point Design Point 3 26-49 C Design Point 10 26-43 C 20
Results of Parametric Study Diagram explanation (next slide) Name Fin length [mm] Pin-Fin thickness [mm] Design Point 1 5 4 Design Point 2 15 4 Design Point 3 25 4 Design Point 4 5 3 Design Point 5 25 3 Design Point 6 15 3 Design Point 7 5 2 Design Point 8 25 2 Design Point 9 15 2 Design Point 10 5 1 Design Point 11 15 1 Design Point 12 25 1 21
Results of Parametric Study 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 Design Point 1 Design Point 2 Design Point 3 Design Point 4 Design Point 5 Design Point 6 Design Point 7 Design Point 8 Design Point 9 Design Point 10 Design Point 11 Design Point 12 0 Fin length Pin-Fin thickness Line type = Fin length Line color = Fin thickness IGBT Tav IGBT Tmax Diode Tav Diode Tmax dpt 22
Summary on What We ve Learned I. CAD embedded CFD can leverage full CAD model parametric II. Cartesian mesh is ideal for automatic meshing with lots of geometry changes during design cycle III. Parametric studies can help to find optimum design and play with variants to see influence of changes (sensitivity) IV. Next Step: Geometry optimization with optimization algorithms 23
Thank you for your attention! 24