the wizards of mahle behr star global conference 2016 prague

MAHLE Behr GmbH & Co. KG © MAHLE MAHLE Behr GmbH & Co. KG © MAHLE

The Wizards of MAHLE Behr

G. Apostolopoulos, R. Stauch, J. Schlottke, M. Weinmann, W. KühnelMAHLE Behr GmbH & Co. KG, Stuttgart, Germany

STAR Global Conference 2016Prague, March 7-9

MAHLE Behr GmbH & Co. KG, TD1M4, G. Apostolopoulos2 © MAHLE

Introduction

MAHLE Group

BUSINESS UNITS

Thermal Management

MAHLE Behr GmbH

Engine Systems andComponents

Filtration and Engine Peripherals

Aftermarket

Sales andApplication Engineering

Advanced Engineering

Air ConditioningHVAC Wizard

Engine CoolingHEEX Wizard

MAHLE is a leading international supplier to the automotive industry

Products for combustion engines/peripherals/filtration/electric vehicles; powertrain cooling and air conditioning

Employees: around 75.000 (2015), Sales: EUR 11,5 billion (2015), 170 production locations in over 30 countries and on five continents

16 major development locations with more than 5,000 development engineers and technicians in Germany, Great Britain, Luxembourg, Slovenia, the USA, Brazil, Japan, China, and India


HEEX Wizard

Engine Cooling

Engine CoolingHEEX Wizard


HEEX Wizard

Workflow of simulation of a Temperature Cycle Test (TCT)

Mapping of temperature data

Thermal stress data

Lifetime predicition and most damaged position

CFD simulation

FEA simulation

Fatigue simulation

Turbulent flow for both fluids Conjugate heat transfer

to and from all solids Heat conduction in solids Dual-cell HX method to model fins

and turbulator inlays Boiling of coolant can be predicted


HEEX Wizard

Geometry preparationGeometry

preparation

Imprinting

MeshingMeshing

Surface Remeshing

Volume structured (External)

Volume unstructured

(STAR-CCM+)

Physical modelingPhysical modeling

Material database

Fin & TubesModeling

Boiling

Radiation

Simulation run

Simulation run

Post-processing

Post-processing

Massflowdistribution

Predefined scenes

Plots

Mapping (NASTRAN)

Mapping (NASTRAN)

Positioning of models

Selective Mapping

Check of correct

mapping

Data transfer format

management

FEA (PERMAS ®)

FEA (PERMAS ®)

Standardized CFD Simulation of a Temperature Cycle Test (TCT)

HEEX Wizard


EGR TCT

iCACTCT

RAD TCT

HEEX Wizard

HEEXWizard

EGR

CAC

RAD

iCAC

Unification of engine cooling simulation methods


HEEX Wizard

Installation and versioning

HEEX Wizard is installed as STAR-CCM+ Plug-In and is available afterwards as an icon in the Wizards toolbar:

.nbm file is distributed for installation

Netbeans IDE 8.0.2 used for development

Statistics of HEEX Wizard:

– Compatible with STAR-CCM+ V9.04

– ~75 JAVA source files

– ~200 defined names for parts,regions, boundaries and interfaces

– ~400 SVN (Subversioning) revisions

– 10 releases of HEEX Wizard

– ~50 buttons, ~80 input fields in GUI


HEEX Wizard

Standardized Excel file for input data

One sheet for each “side” (= fluid) of the heat exchanger

Improvement of reproducibility by compilation of all relevant data for CFD simulation

Standardization of Input Data


HEEX Wizard

Defined Meshing

Setup for defined, robust meshing throughselected parameters

Calculation of thickness of the 1st prism layer based on desired y+ -value

Generation of hybrid meshes (polyhedral, trimmed, imported) possible

Optional refinement for better representation of temperature gradients in headers

MeshingMeshing Physical modelingPhysical modeling

Simulation run

Simulation run

Post-processing

Post-processing Mapping Mapping


HEEX Wizard

Standard materials can be selected by ticking

Conjugate simulation of gas, solid parts and coolant necessary for reliable simulation of heat transfer

Fluid flow and heat transfer outside fins and tubes are simulated in detail (low-Re simulation)

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

Physical Modeling


Simulation run

Simulation run

Post-processing



HEEX Wizard

Standardized Post Processing

Standard screenshots of transient temperature evolution of heat exchanger for creation of animated gif


Simulation run

Simulation run

Post-processing



HEEX Wizard

Mapping of the temperature distribution of the CFD solids to the NASTRAN geometry of the FEA simulation represents the crucial data transfer between CFD and FEA

– Mapping of steady and transient CFD results

– FEA NASTRAN file can contain shell elements

– Selective mapping

Mapping of solid temperature from CFD to FEA


Simulation run

Simulation run

Post-processing



HEEX Wizard

FEA-Results of TCT Simulation

deformation magnification factor: 50

Temperature / °C


Simulation run

Simulation run

Post-processing


-20

0

20

40

60

80

100

120

0 50 100 150 200 250 300

T / °

C

t / s

Inlet Temperature Mapping


HVAC Wizard

Air Conditioning

Air ConditioningHVAC Wizard


HVAC Wizard

Structure of an HVAC unit

Distribution housing

Blower-filter housing

Filter

Evaporator

Heater

Mixing-flaps

PTC - heater

Outside-air-inlet

Recirculation-air-inlet

Blower


HVAC Wizard

HVAC Wizard

Standardized CFD Simulation of a Temperature Control Curve (TCC)


preparation

Automatic Template Creation

Minor surface repair

Prepare/ organize geometry

Physical modelingPhysical modeling

Boundary Conditions

Porosities

Heat Source

Rotate flaps

Rotate flaps

Modus flaps

Mixing flaps

MeshingMeshing

Wrapper

Surface Remeshing

Volume Meshing

Simulation run

Simulation run

Post-processing

Post-processing

Standard PowerPoint

report

Predefined scenes

Plots


HVAC Wizard

Installation and versioning

HVAC Wizard is installed as STAR-CCM+ Plug-In and is available afterwards as a Menu-bar in the STAR-CCM+ Toolbar

.nbm file is distributed for installation

Netbeans IDE 8.0.2 used for development

Statistics of HVAC Wizard:

– Compatible with STAR-CCM+ V10.04 (dev)

– ~60 JAVA source files

– ~200 defined names for parts,regions, boundaries and interfaces

– ~270 SVN (Subversioning) revisions

– ~30 releases of HVAC Wizard

– 11 buttons, Menu-bar with options


HVAC Wizard

Overview

The HVAC Wizard includes a customized GUI for MAHLE Behr that includes:

– Simulation HVAC units for a complete automated TCC simulation (set of single simulations of different mixing flap positions)

– Transient Blower simulations

The different buttons guide the user through the workflow and fire the underlying STAR-CCM+ macros or java panels


preparationPhysical modelingPhysical modeling Rotate flapsRotate flaps MeshingMeshing Simulation

runSimulation

runPost-

processingPost-

processing


HVAC Wizard

Meaning of “Temperature Control Curve”(TCC)

– Typical air temperatures: 5°C after evaporator, 80°C after heater

– The position of the mixing flap controls the mass flow fractions of hot and cold air

For computing the temperature control curve, only the mixing flap position is changed

– Every point of the TCC is one simulation automated process

TCC – Rotation of flaps



runSimulation

runPost-

processingPost-

processing


HVAC Wizard

Automatic PowerPoint report generation:

Scalar scenes

Bar pressure drop graphs

Residual plots

User defined quantities

Automatic PowerPoint Creation



runSimulation

runPost-

processingPost-

processing


MAHLE Behr CFD Wizards

Identification of relevant parts and geometrical structures of the heat exchangers and the HVAC through predefined names

– Parts/regions, surfaces/boundaries, interfaces, continua, field functions

Interactive checking of correct names is possible

Algorithms that check the model for consistency

– Duplicate objects, not-assigned parts, boundaries with multiple interfaces

Naming convention - Release Notes



Significant speed-up of turnaround times for CFD simulation tasks in the development process compared to manual pre-processing of simulation model

Major speed-up potential lays with geometry preparation (imprinting)

Turnaround times and speed-up of CFD Wizards



Imprinting is still a tedious process that requires many manual “remesh – imprint” loops:

Transient blower simulations show bad convergence from v10 → no stable release of HVAC Wizard

Reliability of the software is very important for the development and improvement of the simulation methods → for the product development process

Potential


Summary

Outlook

Further increase of universality and sustainability (as long as STAR-CCM+ provides a stable release)

Further development of features

– HEEX Wizard:

Standardization of geometry data input

Extension of standard post processing (generation of plots, scenes, monitors, reports)

Integration of WHR evaporator as further application

– HVAC Wizard:

Parts-based meshing in combination with boolean subtract method

Integration of MAHLE HVAC Designer tool

MAHLE Behr GmbH & Co. KG © MAHLE MAHLE Behr GmbH & Co. KG © MAHLE

G. Apostolopoulos, R. Stauch, J. Schlottke, M. Weinmann, W. KühnelMAHLE Behr GmbH & Co. KG, Stuttgart, Germany

The Wizards of MAHLE Behr

Thank you for your attention!

the wizards of mahle behr star global conference 2016 prague

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