velocity profile and Re.num.

perry

hi,there,

when I use projection method to solve the incompressible flow around a ideal plate without thickness(for some reasons,I use dimensional NSe!),I find a strange thing,as I change the incoming velocity or(and) the viscosity,and keep the same Res.number,the code donot give a same result,when running my code,I find,when enlarging the viscosity and velocity(the same Re.),iterations for the temperal speed needs many more times(same crit.for convergence),compared with that of small viscosity and small incoming velocity,and the later cannot capture velocity profile for boundary layer,why?

sorry,other questions,if you want to capture the velocity profile among the boundary layer correctly,at least how many grids should be filled among the boundary layer,according to the Re.number(e.g.Re=100)?and the distance for the nearest grid to the surface?

thank