Numerical Investigation for the Laminar Flow Effects over Rough Surface

Abstract

Abstract In this paper, the heat transfer effect of rough surface in laminar flow is introduced by fully developed fields for solving the Navier–Stokes equations of incompressible flow in assuming two-dimension using the direction splitting method. Firstly, the algorithm of the incompressible Navier–Stokes equations with pressure correct is carried out. Secondly, the effects of pressure drop and heat transfer and are investigated and discussed in different rough surface elements which are configured with triangular and rectangular element. The Reynolds number, roughness element spacing, and roughness height are also considered as the factors which affect the heat transfer. The results indicate that the parallel present method reaches the stage of basically stable state rapidly and accurately. Compared with the smooth surface, the global performance of heat transfer is improved by the roughness surface since the pressure drop is lost. The effects of triangular element roughness surface on laminar flow and heat transfer are much stronger than rectangular element roughness surface when the spacing of the rough is changed. The flow over the triangular element roughness surface becomes stronger, which contributes to enhancement heat transfer meanwhile increase the pressure drop when the roughness height is higher.