How Do I Set Up My Problem?
FlexPDE reads a text script that describes in readable language the characteristics of the problem to be solved. In simple applications, the script can be very simple. Complex applications may require much more familiarity with the abilities of FlexPDE.
In the following discussion, we will begin with the simpler features of FlexPDE and gradually introduce more complex features as we proceed.
FlexPDE has a built-in editor with which you can construct your problem script. You can edit the script, run it, edit it some more, and run it again until the result satisfies your needs. You can save the script for later use or as a base for later modifications.
The easiest way to begin a problem setup is to copy a similar problem that already exists.
Whether you start fresh or copy an existing file, there are five basic parts to be defined:
|•||Define the variables and equations|
|•||Define the domain|
|•||Define the material parameters|
|•||Define the boundary conditions|
|•||Specify the graphical output.|
These steps will be described in the following sections. We will use a simple 2D heatflow problem as an example, and start by building the script from the most basic elements of FlexPDE. In later sections, we will elaborate the script, and address the more advanced capabilities of FlexPDE in an evolutionary manner. 3D applications rely heavily on 2D concepts, and will be discussed in a separate chapter.
Note: We will make no attempt in the following to describe all the options that are available to the user at any point, but try to keep the concept clear by illustrating the most common forms. The full range of options is detailed in the FlexPDE Problem Descriptor Reference. Many will also be addressed in subsequent topics.