Dear sahilbhapkar30,
thank you for your question.
The functor dimension can be specified in line 50 and 77 of https://www.openlb.net/DoxyGen/html/d2/d41/latticePhysWallShearStress3D_8hh_source.html by modifying the last argument of the parent SuperLatticePhysF3D<T, DESCRIPTOR>(sLattice, converter, 1).
BR
Stephan