No-slip condition

In fluid dynamics, the no-slip condition is a boundary condition which enforces that at a solid boundary, a viscous fluid attains zero bulk velocity. This boundary condition was first proposed by Osborne Reynolds, who observed this behaviour while performing his influential pipe flow experiments.^[1] The form of this boundary condition is an example of a Dirichlet boundary condition.

In the majority of fluid flows relevant to fluids engineering, the no-slip condition is generally utilised at solid boundaries.^[2] This condition often fails for systems which exhibit non-Newtonian behaviour. Fluids which this condition fails includes common food-stuffs which contain a high fat content, such as mayonnaise or melted cheese.^[3]