Couette flow

Couette flow occurs when a fluid, like air or water, moves between two parallel surfaces, with one surface sliding tangentially relative to the other. Imagine a flat plate sliding over a stationary plate with a thin layer of fluid in between; the fluid near the moving plate is dragged along, creating a velocity gradient. This flow pattern is characterized by a steady, laminar movement where the fluid's speed gradually changes from zero at the stationary surface to the speed of the moving surface. Couette flow is fundamental in understanding shear stress and viscous behavior in fluids under controlled boundary conditions.