The effects of blowing and suction on free convection boundary layers on vertical surfaces with prescribed heat flux

Abstract

The effects that blowing and suction have on the free convection boundary layer on a vertical surface with a given surface heat flux are considered. Similarity equations are derived first, their solution being dependent on the wall flux exponent n and a dimensionless transpiration parameter y, (as well as on the Prandtl number). The range of existence of solutions is considered, with it being shown that solutions exist only for n > -1 for blowing, whereas they exist for all n > n o for suction, where n o < -1 and depends on y. The solutions for strong suction and blowing are derived. In the latter case the asymptotic structure is found to be different for n in the three ranges -1 < n < -, -< n < , n > -. Results are then obtained for the non-similarity problem of constant heat flux with a constant transpiration velocity. Solutions valid for large distances from the leading edge for both suction and blowing are derived.

Mixed convection boundary layer flow over a permeable vertical surface with prescribed wall heat flux

“…Injection or withdrawal of fluid through a porous bounding heated or cooled wall is of general interest in practical problems involving film cooling, control of boundary layers etc. This can lead to enhanced heating (or cooling) of the system and can help to delay the transition from laminar flow (see Chaudhary and Merkin [11]). …”

Role of suction/injection on steady fully developed mixed convection flow in a vertical parallel plate microchannel

“…Injection or withdrawal of fluid through porous heated or cooled surface is of general interest in practical problems involving film cooling, control of boundary layers, etc. This can lead to enhanced heating (or cooling) of the system and can help to delay the transition from laminar flow [25].…”

Stagnation-point flow and mass transfer with chemical reaction past a permeable stretching/shrinking sheet

“…We investigate the skin friction and the mass transfer characteristics at the solid-fluid interface in the presence of chemical reaction. Chaudhary and Merkin [12] studied the injection of fluid through a porous bounding heated or cooled wall is of general interest in practical problems involving film cooling, control of boundary layer and so on. This can lead to enhance heating (or cooling) of the system and can help delay transition from laminar to turbulent flow.…”