Flow and heat transfer of a slightly rarefied gas over a stretching surface

Abstract

The laminar boundary layer flow of an incompressible fluid past a stretching surface was first studied by Crane [1]. Subsequently; various aspects of the flow and heat transfer over a stretching surface have been examined by several investigators [2–11]. In all the above studies, the no-slip boundary conditions are used. In many applications, such as the biological system [12], the cooling of the electronic equipment and Micro-Electro-Mechanical systems (MEM) the fluid behavior might be treated as a rarefied gas [13]. Flow in a rarefied gas is characterized by the value of the Knudsen number Kn. When Kn = 0, the no-slip condition is valid and the continuum flow assumption works well for small Knudsen number Kn 10) the Navier-Stokes equations is not applicable and the kinetic theory of gases must be employed.