Natural convection flow of viscous fluid over triangular wavy horizontal surface

•Triangular wavy surface is not yet considered in the literature for the boundary layer problems.•It is found that sinusoidal wavy surface can exhibit more heat as compared to triangular wavy surface.•The amplitude of the wavy surface plays an important role in enhancement of the heat transfer rate.•It is found difficult to accomplish numerical computations for higher values of amplitude of the wavy surface, i.e. when a > 1.5.

The purpose of this paper is to conduct a numerical study of natural convection flow along an irregular semi-infinite triangular wavy horizontal surface. Coordinate transformation is introduced to transform the boundary layer equations into a form which is more suitable for numerical integration. Implicit finite difference iterative numerical scheme is employed to produce solutions of the problem. Effect of wave amplitude is studied in detail. Important features of the flow field are discussed graphically in terms of skin friction, heat transfer rate, streamlines and isotherms. Although amplitude of the wavy surface play its role in enhancement in the heat transfer rate but it is found difficult to accomplish numerical computations for a > 1.5. Thus, it is concluded that heat liberation is more effective in sinusoidal wavy surface than in triangular surface.