Automation and Standardization of CFD Workflows Dr. Wolfram Kühnel, MAHLE Behr GmbH & Co. KG Unrestricted Siemens AG 2016 Realize innovation.
Outline The company Globalization Standardization Automation Examples HVAC Wizard HEEX Wizard Conclusion 2
The Company The MAHLE Group Group organization Business units and products BUSINESS UNITS Engine Systems and Components Filtration and Engine Peripherals Thermal Management Aftermarket BU1 BU2 BU3 BU4 Founded 1920 MAHLE Behr GmbH Founded 1905 3
The Company The MAHLE Group MAHLE worldwide Headquarter: Stuttgart, Germany R&D Centers NA: Farmington Hill Troy Lockport Amherst Facts (2015): Employees: 75.635 Sales: 11,5 Bill. R&D Centers: 15 4 Production locations Research and development centers
Globalization CFD and FEA engineers @ MAHLE Behr GmbH USA Detroit: / Lockport: / Charleston: -/ Luxembourg: / Germany Stuttgart: / France Rouffach: / For globally comparable simulation results standardized processes and methods are mandatory! China Shanghai: / Wuhan: / R&D centers: #CFD/#FEA < 5 engineers 5 9 engineers > 9 engineers Brazil Jundiaí/Sao Paulo: -/ India Pune MBES: / Pune MBIL: / Central department for simulation method development Development of 3D simulation methods Validation Documentation + Guidelines Training + Support Continuous improvement and enhancement 5
Standardization + Automation Simulation Workflows Automation of standardized simulation workflows helps to ensure the compliance of the work to the guideline reduce manual effort and tedious work reduce errors reduce lead time work collaborative in a global world 6
Standardization + Automation Simulation Workflows - Examples Air Conditioning HVAC Wizard Engine Cooling HEEX Wizard 7
HVAC Wizard Structure of an HVAC unit Outside-air-inlet Mixing-flaps Evaporator Blower-filter housing Air filter Recirculation-air-inlet Distribution housing Auxiliary - heater Heater Blower 8
HVAC Wizard Standardized CFD Simulation Geometry preparation Physical modeling Rotate flaps Meshing Simulation run Postprocessing Automatic Template Creation Boundary Conditions Modus flaps Wrapper Standard PowerPoint report Minor surface repair Porosities Mixing flaps Surface Remeshing Predefined scenes Prepare/ organize geometry Heat Source Volume Meshing Plots HVAC Wizard 9
HVAC Wizard The Tool Installed as a STAR-CCM+ plug-in Fully developed by MAHLE Behr Geometry preparation Physical modeling Rotate flaps Meshing Simulation run Postprocessing > 60 Java source files > 270 subversioning revisions > 30 releases The HVAC Wizard includes a customized GUI for three different CFD workflows: 10
HVAC Wizard TCC Rotation of flaps Meaning of Temperature Control Curve (TCC): Geometry preparation Physical modeling Rotate flaps Air outlet temperature is controlled by mixing hot (from heater) and cold air (evaporator) For computing the temperature control curve, only the mixing flap position is changed -> Every point of the TCC is one steady simulation automated process Meshing Simulation run Postprocessing 11
HVAC Wizard Automatic PowerPoint Creation Automatic report generation (PowerPoint): General informations Scalar scenes Bar pressure drop graphs Residual plots User defined quantities Geometry preparation Physical modeling Rotate flaps Meshing Simulation run Postprocessing 12
Standardization + Automation Simulation Workflows - Examples Air Conditioning HVAC Wizard Engine Cooling HEEX Wizard 13
HEEX Wizard Workflow of simulation of a Temperature Cycle Test (TCT) What is a Temperature Cycle Test (TCT)? No constant operating temperature for automotive heat exchanger => thermal stress => design of heat exchanger has to consider thermal loads for durability and long life-time For component validation: physical TCT durability tests on temperature cycle test benches In development phase: virtual TCT by coupling transient CFD (for timedependant temperature distribution) with FEA (for thermal stress and life-time prediction) Example: test temperature profile (Charge Air Cooler) Temperatures/Cooling Air Mass Flow Temp. Charge Air out Temp. Charge Air in Mass flow Cooling Air 0 90 180 270 360 t [s] 14
HEEX Wizard Workflow of simulation of a Temperature Cycle Test (TCT) CFD simulation Lifetime prediction and most damaged position Fatigue simulation Mapping of temperature data FEA simulation Thermal stress data 15
HEEX Wizard Unification of engine cooling simulation methods icac TCT RAD TCT EGR = Exhaust Gas Radiator EGR TCT EGR CAC = Charge Air Cooler icac HEEX Wizard CAC icac = indirect Charge Air Cooler RAD RAD = Radiator 16
HEEX Wizard Standardized CFD Simulation of a Temperature Cycle Test (TCT) Geometry preparation Meshing Physical modeling Simulation run Postprocessing Mapping (NASTRAN) FEA (PERMAS ) Imprinting Surface Remeshing Material database Massflow distribution Positioning of models Volume structured (External) Fin & Tubes Modeling Predefined scenes Selective Mapping Volume unstructured (STAR-CCM+) Boiling Plots Check of correct mapping Radiation HEEX Wizard Data transfer format management 17
HEEX Wizard Physical Modeling Standard materials can be selected by ticking Conjugate simulation of gas, solid parts and coolant Meshing Physical modeling Simulation run Postprocessing Mapping The fluids of tubes and fins are homogenized by porous media: Pressure loss of tubes and fins is modeled via resistance coefficients of porous media based on Psi-functions Dual-cell HX method to model fins and tubes based on Nu-functions Psi- and Nu-functions are taken from the in-house system simulation database BISS 18
HEEX Wizard Standardized Post Processing Standard screenshots of transient temperature evolution of heat exchanger for creation of animated gif Meshing Physical modeling Simulation run Postprocessing Mapping 19
HEEX Wizard Mapping of solid temperature from CFD to FEA Mapping of the temperature distribution of the CFD solids to the NASTRAN geometry of the FEA simulation Meshing Physical modeling Simulation run Postprocessing Mapping Mapping of steady and transient CFD results (for selected time steps) FEA simulation (in PERMAS ) of thermal load and deformation for each time-step 20
T / C HEEX Wizard FEA-Results of TCT Simulation Meshing Physical modeling Simulation run Postprocessing Mapping Temperature / C 120 100 Inlet Temperature Mapping 80 60 40 20 0-20 0 50 100 150 200 250 300 t / s deformation magnification factor: 50 21
MAHLE Behr CFD Wizards Turnaround times and speed-up of CFD Wizards Significant speed-up of turnaround times Future major speed-up potential lays with geometry preparation (imprinting) HEEX-Wizard time Manual Setup Macro based workflow HEEX- Wizard V9.04_09 Preparing CAD geometry Meshing Setup Meshing Physics Setup Postprocessing 22
Conclusion Standardized, validated and automated simulation workflows promote simulation as an important and integrated part of the development process STAR-CCM+ provides excellent interfaces to automate and customize the workflows High reduction of lead-time by the MAHLE Behr Wizards More than 50% reduction of manual effort by automation Reduction of manual work reduces risk of errors and reduces need for re-work 23
Thank you for your attention! 24