ModelingToolkitStandardLibrary: Thermal Components - creating physically representative components

[matthew-kapp]

Is your feature request related to a problem? Please describe.

I am not used to expressing my model using abstract constants (such as C, G, R, etc.) and am used to expressing my problem using physical constants (Nu, k, Cp, m, etc.). I believe many engineers can relate. Defining external functions to calculate these 'constants' is not practical as sometimes these 'constants' are a function of the material's temperature. I therefore need to modify most of the components, and these modifications might be relevant to other engineers.

Describe the solution you’d like

The change suggested would be to extend ThermalConductor and HeatCapacitor. Convection and radiation could be discussed next.

I believe that most engineering problems could be represented by the following geometries (combinations can be created by connecting together):

1. Flat plate
2. Cylinder
3. Sphere
4. Dome (probably special case of Sphere)

As an example, I would create ThermalCylinder which does the following:

1. Extends ThermalConductor and HeatCapacitor
2. Computes C and G based on density (rho), thermal conductivity (k), and dimensions (Di, Do, L)
3. Optional: Takes in a custom function for k = f(T)

I would then also do ThermalFlatPlate, ThermalSphere, and ThermalDome.