I was trying to implement the Johnson-Champoux-Allard-Pride-Lafarge model, but I'm stuck because I didn't understand how to obtain the Static Viscous Tortuosity and the Static Thermal Tortuosity required in the mathematical formulation.
I did some research and I dind't find anything that could help me. I looked into the book Propagation of Sound in Porous Media by Jean F. Allard and Noureddine Atalla but the explanation about Static Viscous Tortuosity it's pretty short and a bit abstract to comprehend, and I didn't find anything around Static Thermal Tortuosity.
I was following the version of the mathematical formulation presented in the website APMR (Acoustical Porous Material Recipes).
If someone has any suggestion to how I figure it this problem out, please contact me.

Hello I'm Michael the developer of this small project that is just the implementation of some of the models that are use to find the sound absorption coefficient and I'm looking for help.
I implemented the models and so far so good. But I need help to validate that all implementations are correct. So, I need people to test the code, check for errors (within the mathematical formulations I implemented) and also suggest improvements to the project, models that could still be implemented, among other related things.
So, if you have tested the code, I ask you to leave your feedback below.