The Thermal Contact Resistance component models a heat transfer between two materials which have different thermal conductivities.
The following image illustrates an example of apparent contact area of two materials.
Because of the surface roughness of both materials, the actual contact area of two materials becomes spots of contact. The other areas are regarded as the void space filled by fluid such as air. The following image illustrates the mechanism of jointed surface in more detail.
Then heat flow of the contact of two materials is regarded as the following image. This component is based on this.
Using each option, you can control the apparent area size, area ratio, and the thickness of void space by real input signals.That makes it possible for you to change contact resistance value during simulation. For example, change by deformation of actual contact area size caused by joint pressure change.