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CEDRAT News - N° 64 - February 2013 New functionalities in Flux 11.1 thanks to macros. Patrick Lombard - CEDRAT. Flux by CEDRAT M acros have been available under Flux® since 2008. A macro brings the possibility of adding a new functionality to Flux. Macros allow a set of commands to be executed, using pyFlux command language, once questions have been asked of the user. Questions can include the possibility of graphically selecting Flux® components such as points, face regions … as well as existing files opening a Windows® Explorer. The goal of a macro is to automate some tasks, and make using Flux® easier. Flux® is delivered with a list of ready-defined macros. The full list of macros is available in the “C:\Cedrat\Extensions\Macros” directory, with the “macros_list_EN.pdf” file. You will find more macros on the CEDRAT gate (https://gate.cedrat.com). In this paper, we will present some of the macros available: • CreatePathFromLineRegion • Extrude motor in 3D • Compute force on motor teeths for vibro-acoustic analysis Create a path from line region The name of this macro is “CreatePathFromLineRegion”. The main application is for electrostatic analysis, when you want to display electric field along a boundary, to check that the maximum value is below the disrupting field (to avoid dielectric breakdown). Usually, the potentials are defined through line regions, and it is convenient to use the same line regions to check the maximum values of the electric field. Figure1: Example on how to load a macro. Figure 2: Interface of CreatePathFromLineRegion macro. Figure 3: Magnitude of electric field along LOWELEC line region on both sides (up and down). When the macro is loaded, you can execute it (by double clicking on a new icon in the task bar). You are asked different questions: Question Answer Name of path to create Give a specific name Select one line region Select one line region First line of path The goal is to orient the path (when more than one line) Discretisation type: 1 = interval, 2 = point number, 3 = distance Select mode of discretising points along the path Value of discretisation Number of points Yes = discretisation on the entire path, no = discretisation value line Select if number of points is for the whole path or for each line As a result Flux will try to create 2 paths, one corresponding to each side of the path, allowing quantities to be displayed on both sides. If the path is on the boundary of the domain, only one path will be created. In this example, we can display the magnitude value of the electric field along the path on both sides by superposing the curves coming from 2 separate paths. In this example from our electrostatic tutorial, two paths are created: COMPPATH_ LOWELEC_AIR and COMPPATH_LOWELEC_LIQUID (AIR and LIQUID being name of existing face regions). Extrude 2D motor in 3D A set of macros has been created to simplify the creation of motor starting from 2D files. The goal is to benefit from 2D face regions in order to build 3D volumes, and at the same create time 3D volume regions, and assign them to new volumes automatically. Let us see through an example how this works: a motor describing a rear view mirror motor, coming from one of our technical papers in 3D. The challenge here is that the rotor length is different from the magnet length and the stator length. The procedure for building the whole motor is described in the next table: Step Actions 1 Open Flux 3D project 2 Open the Flux 2D project (after removing 2D infinite box) 3 Create transformation of translation for initial rotor extrusion 4 Run the ExtrudeFaceRegion macro 5 Create transformation of translation for extra magnet extrusion 6 Run the ExtrudeFaceWithVolumeRegion macro 7 Run the ExtrudeFaceAndAssignSameVolumeRegion macro 8 Create transformation of translation for extra stator extrusion 9 Run the ExtrudeFaceWithVolumeRegion macro 10 Run the ExtrudeFaceAndAssignSameVolumeRegion macro Figure 4: Initial geometry in 2D. Figure 5: Interface of ExtrudeFaceRegion macro. (see continued on page 7) -6- CEDRAT News - N° 64 - February 2013 The next step is to extrude the magnet and the frame. When you select the faces, you want the new volumes to have the same volume region as the volume below the initial faces. This is what the ExtrudeFaceWithVolumeRegion macro will do. Compute force on motor teeth for vibro-acoustic analysis The aim of this macro is to automatically create sensors on each stator or rotor tooth, in order to compute force vs. time. This force, analysed in one round, can be used for another analysis in vibroacoustic software. Figure 6: Intermediate step. For the region in the middle, what you want is to extrude the faces, and to assign the new volumes to a specific volume region, for instance ROTOR_AIR. You can redo the same procedure for extrusion of the frame. The next step is to extrude the centre and assign it to the STATOR_ AIR region. Figure 9: Interface of CreateSensorFor2DMotorSlotForce macro and resulting sensors. The macro will automatically generate 24 sensors, allowing the force on each stator tooth to be displayed. Each sensor will integrate force density (called DFMAG in Flux) on the line facing the airgap. It is then possible to display force vs. position on each tooth for a healthy motor, or for a motor in which a minor eccentricity has been introduced, because of some mechanical failure or default. As an example, we propose to use the SPM magnet motor corresponding to one of our technical papers. Due to the eccentricity analysis, the whole motor has been described. We have performed a dynamic eccentricity on the rotor. We display the force on one tooth on one round of the motor, when the rotor is centred and when it is not. Figure 7: Interface of ExtrudeFace AndAssignSameVolumeRegion macro. The result is given in the next figure, with the new aided mesh (automatic mesh created by Flux with no user input). Figure 8: Mesh of the resulting motor. Figure 10: Superposition of force on one teeth in healthy and unhealthy motor. s http://www.cedrat.com/en/ industries/e-mobility.html. A World o f Id ea Find our campaign and a lot of interesting articles around this topic in the November 2012 issue of «IEEE spectrum» trade magazine. Modeling/Simulation for Power Conversion couleurs noir 100 gris 50 orange 75 -7-