CAD pacage for electromagnetic and thermal analysis using ... · CAD pacage for electromagnetic and thermal analysis using flnite elements Flux by CEDRAT Magneto Static application

CAD package for electromagnetic and thermal analysis using finite elements

Fluxby CEDRAT

Magneto Static application tutorial 2D basic example

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Flux software : COPYRIGHT CEDRAT/INPG/CNRS/EDF Flux tutorials : COPYRIGHT CEDRAT

This tutorial was edited on 5 juillet 2012

Ref.: KF 2 05 -A- 111 - EN - 07/12

CEDRAT 15 Chemin de Malacher - Inovallée

38246 Meylan Cedex FRANCE

Phone: +33 (0)4 76 90 50 45 Fax: +33 (0)4 56 38 08 30 Email: [email protected]

Web: http://www.cedrat.com

Foreword

*(Please read before starting this document)

Description of the example

The goal of this basic example is to familiarize the user with the Flux Magneto Static application using a simple device. This example contains the general steps and all the data needed to describe the physics,the solving and the postprocessing for the given cases. For this example, the geometry has been previously described in the First steps in using Flux: Geometry and Mesh Tutorial - Basic example.

Required knowledge

This basic example is designed for the user who is already familiar with the basic functions of Flux software. To obtain this knowledge, first, the user should go through the First steps in using Flux: Geometry and Mesh Tutorial - Basic example. This document explains, in detail, all the actions necessary to build the geometry and mesh of a project in the Flux study domain.

Support files included...

To view the completed phases of the example project, the user will find the .py files, including the geometry, physics and post processing descriptions. The .py files corresponding to the different study cases in this example are available in the folder: …\DocExamples11.1\Examples2D\MagnetostaticApplication\

Supplied files are command files written in Pyflux language. The user can launch them in order to automatically recover the Flux projects for each case.

**(.py files are launched by accessing Project/Command file from the Flux drop down menu.)

Supplied files Contents Flux file obtained after launching the .py file

TESTCASE_INI.FLU* Geometry, mesh and physics

Physbuilt.FLU

solving.py Solving process Solved.FLU

CASE1

postprocessing.py Post processing Postprocessed.FLU

TESTCASE_INI.FLU** Initial project solving.py Solving process Solved.FLU

CASE2 postprocessing.py Post processing Postprocessed.FLU

Note : some directories may contain a main.py enabling the launch of the command files

*This file correspond to SENSOR_2D created in the first steps in using Flux- geometry and mesh tutorial

** This file correspond to the Physbuilt.FLU of CASE 1

Flux Table of Contents

PAGE A

Table of Contents 1. General information .................................................................................................................1

1.1. Overview .......................................................................................................................................3 1.1.1. Description of the studied device....................................................................................4 1.1.2. Studied cases .................................................................................................................5

1.2. Strategy to build the Flux project ..................................................................................................7 1.2.1. Main stages for physical description...............................................................................8

2. Construction of the Flux project .............................................................................................11 2.1. Physical description process.......................................................................................................13

2.1.1. Define the physical application .....................................................................................14 2.1.2. Create materials ...........................................................................................................15 2.1.3. Create face regions ......................................................................................................16 2.1.4. Create measuring coils: coil conductors components and coil conductor regions.......17 2.1.5. Assign face regions to faces.........................................................................................18 2.1.6. Orient material for face region ......................................................................................19

3. Case 1: static study ...............................................................................................................21 3.1. Case 1: solving process..............................................................................................................23 3.2. Case 1: results post-processing..................................................................................................25

3.2.1. Display default graphic post processing.......................................................................26 3.2.2. Display arrows of the magnetic flux density on a region boundaries ...........................28 3.2.3. Display isovalues of the magnetic flux density on a 2D grid ........................................29 3.2.4. Compute the magnetic flux density on a point .............................................................31 3.2.5. Compute the magnetic force on face regions...............................................................32 3.2.6. Plot a 2D curve of the magnetic field strength along a path and export the curve.......33 3.2.7. Plot a 2D curve of normal and tangential components of the magnetic field

along a path ..................................................................................................................35

4. Case 2: parametric computation............................................................................................37 4.1. Case 2: solving process..............................................................................................................39 4.2. Case 2: results post-processing..................................................................................................41

4.2.1. Display default graphic post processing (alpha=120°) .................................................42 4.2.2. Create animation of isovalues of the magnetic flux density on face regions

versus position parameter ............................................................................................43 4.2.3. Plot a 2D curve of the flux through coil conductors versus an I/O parameter ..............44 4.2.4. Plot a 3D curve of the magnetic flux density on a path versus an I/O parameter ........45

Table of Contents Flux

PAGE B MAGNETO STATIC APPLICATION TUTORIAL

Flux General information

Magneto Static application tutorial PAGE 1

1. General information

Introduction This chapter contains the presentation of the studied device and the Flux

software.

Contents This chapter contains the following topics:

Topic See Page Overview 3 Strategy to build the Flux project 7

General information Flux

PAGE 2 Magneto Static application tutorial



1.1. Overview

Introduction This section presents the studied device (a variable reluctance speed sensor)

and the strategy of the device description in Flux.

Contents This section contains the following topics:

Topic See Page Description of the studied device 4 Studied cases 5



1.1.1. Description of the studied device

Studied device The device to be analyzed is a variable reluctance speed sensor.

The studied device consists of: a cogged wheel (made of steel) with three teeth two probes with a magnet (made of ferrite) and a coil around each

PROBE 2

COIL 2-

COIL 2+

MAGNET 1

COIL 1-

COIL 1+

WHEEL

MAGNET 2

PROBE 1

Operating principle

The rotation of the cogged wheel near the tip of the probes changes the magnetic flux around probes 1 and 2, creating an analog voltage signal that can be measured by the probes.



1.1.2. Studied cases

Studied cases Two cases are carried out with the Magneto Static application:

case 1: static study (mono value) case 2: multi-parametric static study (multi values)

Case 1 The first case is a static study (mono value).

In this case, the study is performed in the middle position: the two probes between two teeth. The geometric parameter , which allows us to control the angle of the wheel around Z axis, has a fixed value = 75° . The coils are not current supplied (=measuring coils)

Case 2 The second case is a multi-parametric static study (multi values)

In this parameterized study, the angle of the cogged wheel will vary. The geometric parameter varies in the range [75°, 195°] with a step of 3°.





1.2. Strategy to build the Flux project

Introduction This section presents outlines of physical properties description process of the

sensor.


Topic See Page

Main stages for physical description 8



1.2.1. Main stages for physical description

Outline An outline of the physical description process of the sensor is presented in

the table below.

Stage Description

1

Definition of the application and definition of the depth of the domain

Magneto Static 2D (solved with Flux 3D solver)

2D plan (6mm)

2 Creation of two materials

FERRITE – magnet with a linear B(H) characteristic

STEEL – ferromagnetic material with a non linear B(H) characteristic

3 Creation of four face region

AIR_EXT region, corresponding with the air surrounding the device

AIR_WHEEL region, corresponding with the air in the cogged wheel

MAGNET1 region corresponding with the first magnet of the device

MAGNET2 re region corresponding with the second magnet of the device

4

Creation of two coils: Two components Four face regions

COIL_CONDUCTOR1 COIL_CONDUCTOR2 COIL1N region, corresponding with the

negative part of the first coil COIL1P region, corresponding with the

positive part of the first coil COIL2N region, corresponding with the

negative part of the second coil COIL2P region, corresponding with the

positive part of the second coil

Continued on next page



Stage Description

5 Assignment of face regions

INFINITE

AIR WHEEL

AIR_EXT

COIL1P

MAGNET1

COIL1N

COIL2P

MAGNET2

COIL2N

WHEEL

6 Material orientation

Construction of the Flux project Flux


Flux Construction of the Flux project


2. Construction of the Flux project

Introduction This chapter contains the physical description of the sensor. For a more

detailed description of the basic geometry of the sensor, the user should reference the Flux 2D Generic Tutorial of Geometry and Mesh. The user must have good understanding of all functionalities of the Flux preprocessor.

Starting Flux project

The starting project is the Flux project GEO_MESH.FLU. This project contains: the geometry description of the contactor the mesh of the computation domain

New Flux project

The new Flux project is GEO_MESH_PHYS.FLU.


Topic See Page Physical description process 13





2.1. Physical description process

Introduction This section presents the definition of the physical properties – materials and

regions.


Topic See Page Define the physical application 14 Create materials 15 Create face regions 13 Create measuring coils: coil conductors components and coil conductor regions

14

Assign face regions to faces 18 Orient material for face region 19



2.1.1. Define the physical application

Goal First, the physical application is defined. The required physical application is

the Magneto Static 2D application.

Data The characteristics of the application are presented in the table below.

Magneto Static 2D application

Definition 2D domain type Depth of the domain

Coils Coefficient

2D plane 6 mm Automatic Coefficient

Application Define Magnetic Magneto Static 2D



2.1.2. Create materials

Goal Two materials are created directly for the physical description of the sensor;

the two materials are characterized by their magnetic properties: the first material is FERRITE defined for the coiled magnets the second material is STEEL defined for the cogged wheel

Data The characteristics of the materials are presented in the tables below.

B(H) linear magnet described in the Br module

Name Remanent flux density (T) Relative permeability FERRITE 0.8 1

B(H) isotropic analytic saturation (arctg 2 coef.)

Name Initial relative permeability Saturation magnetization

(T) STEEL 5000 1.9

Physics Material New



2.1.3. Create face regions

Goal Five face regions are necessary for the physical description of the sensor.

Five following face regions will be created: the AIR_EXT region, corresponding with the air surrounding the device the AIR_WHEEL region, corresponding with the air in the cogged wheel the MAGNET1 region, corresponding with the first magnet of the device the MAGNET2 region, corresponding with the second magnet of the device the WHEEL region, corresponding with the cogged wheel

The INFINITE region, already created during the infinite box creation, will be edited to activate its physical properties.

Data The characteristics of the face regions are presented in the table below.

Face region

Name Type Material Color AIR_EXT Air or vacuum region Turquoise

AIR_WHEEL Air or vacuum region Turquoise INFINITE* Air or vacuum region Turquoise MAGNET1 Magnetic non-conducting region FERRITE Magenta MAGNET2 Magnetic non-conducting region FERRITE Magenta WHEEL Magnetic non-conducting region STEEL Cyan

Physics Face region New

*The region already created and assigned during the creation of the infinite box, however the user need to enter the type of the region.



2.1.4. Create measuring coils: coil conductors components and coil conductor regions

Goal Two coils are created to measure the flux density.

About coil In magnetic applications, a coil is represented by one face region or by a

group of face regions of the coil conductor type. The value I of the current in a wire (or turn) of the coil is set by means of an electric component (of coil conductor type) associated to the coil.

Data (1) The characteristics of the electric components (of coil conductor type) are

presented in the table below:

Stranded coil conductor with imposed current (A)

Name comment Value COIL_CONDUCTOR1 Coil conductor on the first coil 0 COIL_CONDUCTOR2 Coil conductor on the second coil 0

Physics Electrical components Stranded coil conductor New

Data (2) The characteristics of the regions (of coil conductor type) are presented in the

table below:

Coil conductor type region

Face region Component

Orientation Turn number Series or parallel

Color

COIL1N COIL_CONDUCTOR1 negative 1000 series red COIL1P COIL_CONDUCTOR1 positive 1000 series red COIL2N COIL_CONDUCTOR2 negative 1000 series red COIL2P COIL_CONDUCTOR2 positive 1000 series red

Physics Face region New

the COIL1N region, corresponding with the negative part of the first coil the COIL1P region, corresponding with the positive part of the first coil the COIL2N region, corresponding with the negative part of the second coil the COIL2P region, corresponding with the positive part of the second coil



2.1.5. Assign face regions to faces

Goal The INFINITE region has been already assigned during the creation of the

infinite box. The nine regions (AIR_EXT, AIR_INT, WHEEL, COIL1P, COIL1N, MAGNET1, COIL2P, COIL2N, and MAGNET2) are assigned to faces.

Outline The region assignment is presented in the figure below.

INFINITE

AIR_WHEEL

AIR_EXT

COIL1P

MAGNET1

COIL1N

COIL2P

MAGNET2

COIL2N

WHEEL



2.1.6. Orient material for face region

Goal An orientation of the material region is needed to describe physics.

Data The orientation of the material region is related in the table below

Orient material for face region

Name Oriented type Coordinate system Angle MAGNET1 Direction PROBE_CS 0 MAGNET2 Direction PROBE_CS001 0

Physics Face region Orient material for face region

Case 1: static study Flux


Flux Case 1: static study


3. Case 1: static study

Case 1 The first case is a static study.

This study is a very easy problem of Magneto Statics. In this study, a magneto static analysis of the sensor is performed in a medium position: the two probes between two teeth. A geometric parameter , which allow us to control the angle of the wheel around Z axis, has a fixed value = 75° The coils are not current supplied (=measuring coils)


The starting project is the Flux project TestCase_INI.FLU. This project contains: the geometry description of the device the mesh and computation domain the initial physical description of the contactor


Topic See Page Case 1: solving process 23 Case 1: results post-processing 25





3.1. Case 1: solving process

Goal The case 1 is solved using the default scenario with reference values.

Action Solve case 1.

Solving Solve





3.2. Case 1: results post-processing

Introduction This section explains how to analyze the principal results of case 1.


Topic See Page Display default graphic post processing 26 Display arrows of the magnetic flux density on a region boundaries

28

Display isovalues of the magnetic flux density on a 2D grid 29 Compute the magnetic flux density on a point 31 Compute the magnetic force on face regions 32 Plot a 2D curve of the magnetic field strength along a path and export the curve

33

Plot a 2D curve of normal and tangential components of the magnetic field along a path

35



3.2.1. Display default graphic post processing

Goal The default graphic post processing is displayed on the device (excluding the

infinite box) : - Isovalues of the magnetic flux density - Arrows of the magnetic flux density - Isolines of the vector potential

Action (1) Display isovalues

Graphic Isovalues Display isovalues

Result (1) The following chart shows the isovalues of the magnetic flux density on the

device.




Action (2) Hide previous isovalues and display arrows

Graphic Arrows Spatial Group Display arrows

Result (2) The following chart shows the arrows of the magnetic flux density on the

device.

Action (3) Display isolines

Graphic Isolines Display isolines

Result (3) The following chart shows the isolines of the vector potential on the device.



3.2.2. Display arrows of the magnetic flux density on a region boundaries

Goal The arrows of the magnetic flux density on wheel region boundaries are

displayed.

Data The characteristics of the arrows are presented in the table below.

Arrows on boundary

Name Groups Quantity WHEEL_CONTOUR S_WHEEL Magnetic flux density / Vector

Graphic Arrows boundary New

Result The result is presented in the figure below :



3.2.3. Display isovalues of the magnetic flux density on a 2D grid

Goal One 2D grid is created midpoint of the second stranded coil.

The magnetic flux density isovalues are displayed on the 2D grid.

Data (1) The characteristics of the 2D grid are presented in the table below.

Rectangular 2D grid in XY plane: definition

2D grid origin coordinates Name Comment Coordinate system

First Second GRID_ONMAGNET For the magnet PROBE_CS 0 0

Rectangular 2D grid in XY plane: definition

Characteristics along X Characteristics along Y

Positive X Negative XNumber of

disc. elementsPositive Y Negative Y

Number of disc. elements

12 12 30 6 6 20

Rectangular 2D grid in XY plane: appearance

Visibility Color visible green

Support 2D grid New

Data (2) The characteristics of the isovalues are presented in the table below.

Isovalues on 2D grid

2D grid Quantity GRID_ONMAGNET Magnetic flux density / Vector

Graphic Isovalues New




Result The following chart shows the magnetic flux density on the

GRID_ONMAGNET grid



3.2.4. Compute the magnetic flux density on a point

Goal The magnetic flux density is computed on the selected point.

Data The characteristics of the point are presented in the table below.

Quantities computation on points

Name Comment Formula

POINT1 Center of the magnet B

Point defined by its coordinates

Coordinates localization Coord. system Region first second

0 0 no constraint PROBE_CS001 MAGNET2

Computation On point New session Quantities computation on points

Result The following values show the X and Y components of the magnetic flux

density at the above-described point.



3.2.5. Compute the magnetic force on face regions

Goal The value of the magnetic force is computed on the selected face region and

the result of computation is displayed in the dialog box.

Data The characteristics of the magnetic force computation are presented in the

table below.

Compute on physic entity

Region Name

Spatial group Quantity Magnetic force / Magnitude

Magnetic force / x component FORCE_MAGNET S_MAGNET2 Magnetic force / y component

Computation On physical entity Compute

Result The following dialog box shows the result of computation of the magnetic

force on the MAGNET2 face region.



3.2.6. Plot a 2D curve of the magnetic field strength along a path and export the curve

Goal The variation of the magnetic flux density is computed along the selected path

and displayed as curve.

Data (1) The characteristics of the path are presented in the table below.

Path defined by 2 points

Name Comment SEGMENT Along the magnet

Path defined by coordinates

Path points Starting point Ending point

Coordinates Coordinates Coord. system

First Second Coord. system

First Second

Discretization by intervals

PROBE_CS001 -15 0 PROBE_CS001 15 0 50

Support Path New

Data (2) The characteristics of the curve are presented in the table below.

2D curve (path)

Name Comment Path Quantity Magnetic field /

Magnitude Magnetic field /

Normal component CURVE

Magnetic field strength along the segment in magnet

SEGMENT

Magnetic field / Tangential component

Curve 2D curve (Path) New 2D curve (Path)




Result The following curves show the components of the magnetic field strength

along the X and Y –axes with Absolute view mode.

Action Export the curve to excel file

Curve 2D curve (path) Excel export



3.2.7. Plot a 2D curve of normal and tangential components of the magnetic field along a path

Goal The variation of the normal and tangent components of the magnetic field is

computed along the selected path and displayed as curve.

Data (1) The characteristics of the path are presented in the table below.

Arc defined by center, radius and angles

Name Comment AIR_GAP In the air gap

Path definition

Center of arc Extremities angles

around Z Coord. system

First Second Starting Ending Radius Region

Discretization by intervals

XY1 0 0 -40 70 21.75 AIR_EXT 30

Support Path New

Data (2) The characteristics of the curve are presented in the table below.

2D curve (path)

Name Comment Path Quantity Magnetic field /

Normal component CURVE_1

Normal and tangent magnetic field along the air gap

AIR_GAP Magnetic field /

Tangential component

Curve 2D curve (Path) New 2D curve (Path)




Result The following curves show the normal and tangent components of the

magnetic field along the X and Y -axes.

Flux Case 2: parametric computation


4. Case 2: parametric computation

Case 2 The second case is a parametric computation.

The angle of the cogged wheel will vary. In this parametric study, the geometric parameter is the angle that varies in the range [75°, 195°] with a step of 3°.


The starting project is the Flux project GEO_MESH_PHYS.FLU. This project contains: the geometry description of the device the mesh and computation domain the initial physical description of the contactor

Project name The new Flux project is saved under the name of CASE2.FLU.


Topic See Page Case 2: solving process 39 Case 2: results post-processing 41

Case 2: parametric computation Flux




4.1. Case 2: solving process

Goal The scenario with the controlled geometrical parameter is defined for a

varying solving process.

Data The characteristics of the solving scenario are presented in the tables below.

Solving scenario

Name Comment SCENARIO1 study using a geometrical parameter

Solving scenario

Parameter control Interval

Controlled parameter

Type Lower limit

Higher limit

Method Step value

ALPHA Multi-values 75 195 step

value 3

Solving Solving scenario New

Solving Solve





4.2. Case 2: results post-processing

Introduction This section explains how to analyze the principal results of case 2.


Topic See Page Display default graphic post processing (alpha=120°) 42 Create animation of isovalues of the magnetic flux density on face regions versus position parameter

43

Plot a 2D curve of the flux through coil conductors versus an I/O parameter

44

Plot a 3D curve of the magnetic flux density on a path versus an I/O parameter

45



4.2.1. Display default graphic post processing (alpha=120°)

Action First, the computation step of the geometrical parameterized study is selected

(alpha=120°). Then, the default graphic post processing is displayed via isovalue plots of color shadings.

Select the step

Data The characteristics of the scenario and computation step selection are

presented in the table below.

Scenario and computation step

Computation step Scenario

Parameter name Value SCENARIO1 ALPHA 120

Action Display isovalues

Graphic Isovalues Display isovalues

Result The following chart shows the magnetic flux density on the selected regions.



4.2.2. Create animation of isovalues of the magnetic flux density on face regions versus position parameter

Goal The animation of isovalues of the magnetic flux density for different positions

of the wheel is created.

Data The characteristics of the animation are presented in the table below.

Animation

General Display Pilot

Name Parameters min max

Steps frequency

1/

Build options

Isovalues

ANIMATION_1 ALPHA 75 195 2 Build video

4_ISOVAL_NO_INFI

NITE

Graphic Animation New

Result The animation video is created in the project repertory in a .AVI file.



4.2.3. Plot a 2D curve of the flux through coil conductors versus an I/O parameter

Goal The values of the flux through the two coil conductor versus the angular

position of the cogged wheel are computed and displayed in a curve

Data The characteristics of the curve are presented in the table below

2D curve (I/O parameter)

Parameter Circuit Name

Name Lower

endpoint Upper

endpoint COILCONDUCTOR1 COILCONDUCTOR2

CURVE ALPHA 75° 195° Flux Flux

Curve 2D Curve I/O parameter New 2D Curve (I/O parameter)

Result The following curves show the variation of flux through coil conductor in

function of the angle variation of the cogged wheel.



4.2.4. Plot a 3D curve of the magnetic flux density on a path versus an I/O parameter

Goal The variation of the magnetic flux density is computed along the selected path

(already defined in case 1) for different positions of the wheel and displayed as curve.

Data The characteristics of the curve are presented in the table below

3D curve (Path + I/O parameter)

Parameter Name Path

Name Min Max Quantity

CURVE_1 AIR_GAP ALPHA 75 195 Magnetic flux density /

Magnitude

Curve 3D Curve (Path + I/O parameter) New 3D Curve (Path + I/O parameter)

Result The following curve shows the variation of the magnetic flux density along

the path for different positions of the wheel.



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CAD pacage for electromagnetic and thermal analysis using ... · CAD pacage for electromagnetic and thermal analysis using flnite elements Flux by CEDRAT Magneto Static application