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EM.Ferma

2,103 bytes removed, 01:15, 6 September 2016
/* Building the Physical Structure in EM.Ferma */
=== Grouping Objects by Material or Source Type ===
Your physical structure in EM.Ferma is typically made up of some kind of source object either in the free space or in the presence of one or more material objects. EM.Ferma's electrostatic and magnetostatic simulation engines then discretize these source and material objects and solve the Laplace or Poisson equations to find the electric or magnetic fields everywhere in the computational domain.
All the CAD geometric objects in the project workspace are organized together into object groups which share the same properties including color and electric or magnetic [[parameters]]. Once a new object group node has been created on in the navigation tree, it becomes the "Active" object group of the project workspace, which is always listed in bold letters. When you draw a new CAD geometric object such as a Box box or a Spheresphere, it its name is inserted added under the currently active surface typeobject group. There is only one object group that is active at any time. Any group can be made active by right -clicking on its name in the navigation tree and selecting the '''Activate''' item of the contextual menu. It is recommended that you first create object groups, and then draw new objects under the active surface group. However, if you start a new EM.Ferma project from scratch, and start drawing a new object without having previously defined any object groups, a new default Fixed-potential PEC object group with a fixed zero voltage is created and added to the navigation tree to hold your new CAD geometric object.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Defining_Materials_in_EM.Cube#Defining_a_New_Material_Group | Defining a New Object Group]]'''.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Defining_Materials_in_EM.Cube#Moving_Objects_among_Material_Groups | Moving Objects among Different Groups]]'''.
 
=== Variety of Material Objects ===
 
[[Image:Static1.png|thumb|330px| EM.Ferma's PEC dialog.]]
EM.Ferma offers the following types of material objects for construction of your physical structure (click on each type to learn more about it):
 
 
* '''[[Defining_Materials_in_EM.Cube#Perfect_Electric_Conductors_.26_Metal_Traces | Perfect Electric Conductors (PEC)]]''': A perfect electric conductor (PEC) is a material with &epsilon;<sub>r</sub> = 1 and &sigma; = &infin;.
* '''[[Defining_Materials_in_EM.Cube#Defining_Dielectric_Materials | Dielectric/Magnetic Materials]]''': You can define dielectric materials with the relative permittivity &epsilon;<sub>r</sub> and electric conductivity &sigma; for electrostatic analysis or magnetic (permeable) materials with the relative permeability &mu;<sub>r</sub> for magnetostatic analysis.
 
[[Image:Info_icon.png|40px]] Click here for a general discussion of '''[[Defining Materials in EM.Cube]]'''.
 
{{Note| You can define any solid or surface object as a fixed-potential PEC object.}}
 
{{Note| Excluding surface and curve CAD objects, you can define any solid CAD object as a dielectric or magnetic material object.}}
 
=== Variety of Source Objects ===
 
EM.Ferma also offers the following types of source objects for excitation of your physical structure:
 
* '''[[#Using_Fixed-Potential_PEC_Objects_as_Voltage_Sources | Fixed-Potential PEC Objects]]'''
* '''Volume Charges''': For volume charge sources you need to specify a positive or negative charge density in C/m<sup>3</sup>. You can draw all kinds of solid CAD objects under this group.
* '''Volume Currents''': For volume current sources you need to specify a current density in A/m<sup>2</sup>. You can draw all kinds of solid CAD objects under this group. Note that current density is a vectorial quantity and has a magnitude and a unit direction vector.
* '''[[#Wire_Current_Sources | Wire Currents]]'''
* '''[[#Permanent_Magnets | Permanent Magnets]]'''
 
<table>
<tr>
<td> [[Image:Static3.png|thumb|330px| EM.Ferma's Charge Source dialog.]] </td>
<td> [[Image:Static5.png|thumb|330px| EM.Ferma's Volume Current Source dialog.]] </td>
</tr>
</table>
=== A Note on Material and Source Types in EM.Ferma ===
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