Changes
In this tutorial you will learn about the third type of magnetic source, <i>i.e.</i> a permanent magnets. You will also learn how to define a new variable and parameterize your physical structure subject to a certain constraint.
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== Getting Started ==
! scope="col"| Plot Type
! scope="col"| Max. Size
! scope="col"| Cone Length Ratio! scope="col"| Cone Radius Ratio
|-
! scope="row"| Sensor_1
| (0, 0, 0)
| | Intensity
| -
| -
| -
| 1.5
| 0.75
| 0.25
|-
! scope="row"| Sensor_3
| 1.5
| 0.75
| 0.25
|}
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Also open the data manager and plot the data file "Sensor_1_Z_HTotal.DAT" in EM.Grid. This plot shows the variation of the magnetic field at the center of the magnets along the Z-axis. At z = 25mm, the magnetic field intensity is 260A275A/m.
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Next, you have to associate this variable with the object properties. This requires a little bit of thinking. The height of the two cylinders must be set equal (50mm - gap_h)/2. This makes the total height of your structure h<sub>tot</sub> = (50mm - gap_h)/2 + gap_h + (50mm - gap_h)/2 = 50mm, as you want. In [[EM.Cube]], the local coordinate system (LCS) of a cylinder is always set up at the center of its bottom base. As you vary "gap_h", the bottom of "Cylinder_1" will always stay fixed at Z = 0, while the bottom of "Cylinder_2" must be located at 50 - (50mm - gap_h)/2 = 25mm + gap_h/2.
Open the property dialog of "Cylinder_1" and set its height equal to "(50-gap_h)/2". Then, open the property dialog of "Cylinder_2", set its height equal to "(50-gap_h)/2" and set its Z-coordinate to "25+gap_h/2".
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Also open the data manager and plot the data file "Sensor_1_Z_HTotal.DAT" in EM.Grid. The figure below shows that at z = 25mm, the magnetic field intensity has increased to 357A/m.
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== Simulating Permeable Magnets ==
In the previous parts, you assumed that the relative permeability of the permanent magnets was μ<sub>r</sub> = 1. Alnico is a permanent magnet material with μ<sub>r</sub> = 3.6. Open the property dialog of the group groups "PM_1" and "PM_2" in the navigation tree and change its relative permittivity to 3.6.
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Open the data manager and plot the data file "Sensor_1_Z_HTotal.DAT" in EM.Grid. You can see that along the Z-axis at the center of the two magnets, the field is very much localized and confined to the air gap region and its intensity has increased to a very high value of 634A/m.
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<p> </p>
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