Have a question about Zou-He pressure boundary condition


I’m doing work about 2D flow in porous media. And I’m planning to construct simulation tool based on LBM.

To make pressure boundary condition, I’ve been reading " Qisu zou et al, On pressure and velocity boundary conditions for the lattice Boltzmann BGK model, Phys. Fluids 9 (6), 1997".

So, my question is
“To make inlet pressure value, Is it enough to use relationship between pressure and density?”

I mean, if I just use rho = p/(rho_0*c_s^2 ) relationship and get f_1, f_5, f_8 in inlet, is this right process to make inlet pressure BC?

I have some doubts because I saw some different method of Zou-He boundary condition using DIRICHLET boundary condition (in cylinder.m open source). And I thought DIRICHLET boundary condition in cyclinder.m seems only suitable for Poiseuille flow between parallel plate.

Thank you for your reading.