Bödewadt flow and heat transfer over a stretching stationary disk

• Stretching causes reduction in the growth of boundary layer.
• Stretching gives rise to a rigid-body rotation of the most of the revolving fluid just above the disk.
• Stretching enhances both the skin friction at the wall and volume of fluid at the far field.
• Increasing stretching drastically lowers the thickness of thermal boundary layer,
• Stretching seems to play a significant role in the wall cooling processes.

The three-dimensional motion of flow due to the rotation of a viscous fluid at a sufficiently large distance from a stationary disk, the so-called classical Bödewadt boundary layer flow, is extended in this paper for the first time in the literature to the case where the stationary disk is permitted to uniformly stretch in the radial direction. The effects of such a stretching mechanism on the flow and heat characteristics are of present concern for this physical problem. A conventional transformation is shown to lead to a set of similarity equations which are coupled and highly nonlinear. It is found that the traditional Bödewadt boundary layer is greatly altered under the influence of radial stretching of the wall. As a consequence of reduction in the momentum boundary layer, the thickness of the thermal boundary layer is also observed to considerably decrease even for moderate strength of stretching. This outcome is prominently important from the technological point of view since the radial stretching may serve to cool down the system in practical applications.