In this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. The inner and outer cylinders are kept at constanttemperature Ti and To respectively, where Ti>To. The annular space is filled with Alumina-water nanofluid.The governing equations with the corresponded boundary conditions in the polar coord...

Entropy generation for natural convection in a partitioned cavity, with adiabatic horizontal and isothermally cooled vertical walls, is studied numerically by both a FORTRAN code and the commercially available CFD-ACE software. Effects of the Rayleigh number, the position of the heated partition, and the dimensionless temperature difference on the local and average entropy generation rate are i...

This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%-0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigate...

In this article, entropy generation on viscous nanofluid through a horizontal Riga plate has been examined. The present flow problem consists of continuity, linear momentum, thermal energy, and nanoparticle concentration equation which are simplified with the help of Oberbeck-Boussinesq approximation. The resulting highly nonlinear coupled partial differential equations are solved numerically b...

Navier-Stokes simulations of three-dimensional flow and augmented convection in a channel with symmetric, transverse grooves on two opposite walls were performed for 180 <Re<1600 using the spectral element technique. A series of flow transitions was observed as the Reynolds number was increased, from steady two-dimensional flow, to traveling two and three-dimensional wave structures, and finall...

Numerical investigation of heat transfer over a backward facing step (BFS), using nanofluids is presented. Different volume fractions of nanoparticles are presented in the base fluid besides different type of nanoparticles have been used. The finite volume technique is used to solve the momentum and energy equations. The distribution of Nusselt number at the top and the bottom walls of the BFS ...

The attention of the present paper is focused on the intensive heat removal with arrays of impinging jets. Three jet configurations are tested which involve variation of geometric parameters such as nozzle shape, diameter and nozzle-tonozzle spacing and impingement distance and of flow rate. The convective heat transfer coefficient is measured with infrared thermography applied to the heatedthi...

The combined effects of Soret and Dufour on an unsteady mixed convection magnetohydrodynamics heat and mass transfer in a micropolar fluid saturated Darcian porous medium in the presence of thermal radiation, heat generation, Ohmic heating and chemical reaction have been investigated. The transformed boundary layer equations are solved numerically by applying Keller-box method. Comparison of nu...