RMS Surface Roughness and Conductivity

Selecting the Hammerstad-Jensen model and specifying Conductor Surface Roughness options allows the PSI and SIwave solvers to use a more refined conductivity calculation. There are two types of conductor roughness models: Exponential (K_W) and Hammerstad (K_H). When you use one of these models, the user-specified RMS surface roughness value affects the calculation of metal conductivity, which changes according to the following equations:

Where:

• K can be K_H or K_W, the loss coefficients in the two models.
• s and h are the surface RMS roughness parameters.