I Is shear stress at the pipe wall the same for turbulent and laminar flows?

[A.T.]

do i see this not moving fluid with my naked eye? Yes

Compare the position of the right tip of the dyed fluid between 0.09 and 0.18. It very slowly moves left. You need longer experiments than just a few seconds.

If it has no thickness to be considered a layer how come i observe this so easily?

"No thickness" applies to the mathematical continuum model. In reality you have particles and surface irregularities of finite size.

 

[lost captain]

Compare the position of the right tip of the dyed fluid between 0.09 and 0.18. It very slowly moves left. You need longer experiments than just a few seconds.


"No thickness" applies to the mathematical continuum model. In reality you have particles and surface irregularities of finite size.

Okay thank you very much. Could you also answer me this: is the friction at the walls of the pipe applied at the moving layer on top of the no slip condition?