I simulate the turbulent flow in a horizontal pipe.
When I check the results and compare them with the experimental data, I see a huge deviation at the wall, in the middle of the pipe it matches perfectly. I use no-slip condition at the wall. I don’t know why velocity is not zero at the wall.
See the result: https://ibb.co/BtXXVgm
Is it because of grid resolution (currently I use N=80, the pipe diameter is 40mm and length 1500mm)?
Please share your thoughts.