Update PdfFieldInitializer
The lbm::PdfFieldInitializer uses cell-based variables (x|y|z, nx|ny|nz). This is problematic in simulations with refinement. A solution is to the cell-based variables to real variables, i.e. change nx to xsize (length).
The lbm::PdfFieldInitializer uses cell-based variables (x|y|z, nx|ny|nz). This is problematic in simulations with refinement. A solution is to the cell-based variables to real variables, i.e. change nx to xsize (length).