Ch1: Shear Stresses and Boundary Layers

[@captainamericawhyso5917]

Great video, sir. Thank you so much. I have a question though.
When we talk about friction in the pipe walls, is this friction between the non moving fluid that has zero velocity (no slip condition) and the pipe walls or is it between the non moving fluid and the moving fluid atop of it ?

[@eronbrayanaiolfi95]

What is the textbook that contains this example?

[@MrJaapjeAapje]

Hey guys! I'm working in research on a topic called 'organ-on-a-chip' which uses shear stress to mechanically stimulate cells. Currently I'm looking in depth at the physics side of this topic. However, based on this video and the 'no-slip condition' it seems to me like this mechanical stimulation is not achieved since the cells in my system are basically located at the place where the dye is injected to the wall, which stays put and does not experience flow/shear stress. Am I correct? Thanks

[@matthieulouise8323]

if y= -h, then du/dy should be +ve Sir. Don't you think so ?

[@kansaandre]

Thanks, great explanation!

[@Nacho1234]

Dear Casey, I think your du/dy is wrong since h should be squared, and so in (tau)xy

[@tome.34]

I think the error is at the sign of "3U/h". Should be positive if evaluated when y = - h

[@nastarantamjidi3917]

Thanks

[@shallah9920]

why is y=-h

[@caseyharwood5038]

The origin is defined mid-way between the two walls, so the upper wall is at y=h, the lower wall is at y=-h, and the center is at y=0.

[@shallah9920]

that makes sense, thank you