The no slip effect causes the fluid near the surface of the plate to be

# The no slip effect causes the fluid near the surface

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The no-slip effect causes the fluid near the surface of the plate to be subjected to largeshear forces. These shear forces lead to a local rotation of the fluid particles, known asvorticity of the fluid field. It turns out that this vorticity is advected by the upward flowaway from the plate. At this point in the course, we do not yet have the mathematicaltools needed to understand and verify this effect, so we will just accept it as an experi-mental fact. The part of the flow field above the plate where there are strong shear stressin the fluid is known asthe boundary layer.
fluid mechanics chapter 4 lecture notesCopyright©Wayne Hacker 2015. All rights reserved.47The fluid far from the plate will barely be affected by the vorticity shedding off of theplate. The shear forces outside the boundary layer in the flow field are typically non-existent, or at least small enough that they can be ignored. We refer to this region asthe free-flow field. This vorticity-free region surrounding the plate is typically classifiedas a region of irrotational flow (no vorticity).The boundary between the boundary layer and the free-stream is known as the edgeof boundary layer, and is mathematically denoted byy=δ(x), wherexrepresents thedistance downstream of the leading edge (see figure below).