ABSTRACT

Using the standard k-e and wall function models, a two-dimensional turbulent pipe flow was simulated with and without cavities. The Reynolds number was fixed at 40,000. The simulation was carried out using SIMPLE and second-order schemes. The linearized equations were solved using Gauss-Seidel method. 160,000 structured computational grids were used. Uncertainty was approximated through experimental validation and grid independence. Dimple concentration effect on flow and heat transfer characteristics was investigated. The simulation revealed circulation inside the cavities. Cavity boundaries were shown to contribute significantly towards turbulence production. Increase in cavity concentration was shown to enhance heat transfer with adverseeffect on pressure drop.