Physical models pf pressure diffusion can be split into two categories: Newtonian and Rheological (non-Newtonian) based on the fluid stress model.
Mathematical mdoels of pressure diffusion can be split into three categories: Linear, Pseudo-linear and Non-linear.
Solvers for the above problems can be Numerical, Analytical or Hybrid.
Many popular 1DR solutions can be approximated by universal equation of 1DR pressure diffusion which has a big methodological value.
The simplest analytical solutions for pressure diffusion is captured by 1DL Linear-Drive Solution (LDS) and 1DR Line Source Solution (LSS)