Question

When the velocity at a point becomes zero, it refers to ___________

(a) slip condition

(b) no slip condition

(c) positive slip condition

(d) negative slip condition

This question was addressed to me in an interview for job.

This question is from Doublet Flow in section Inviscid & Incompressible Flow of Aerodynamics

Answer 1

Right choice is (b) no slip condition

The explanation is: At the boundary of solids, the velocity at a point becomes zero. Dirichlet’s condition is an example of no slip-condition. When the adhesive forces are stronger than cohesive force the particle does not move and hence no slip-condition occurs.