In this paper, convection heat transfer of Al2O3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. For each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. The governing equations in...

The disposal of Waste Activated Sludge is a major problem. The paper presents several disposal routes. The ultimate steps in these routes are indirect drying and subsequent incineration. Although the design of the indirect dryers is straightforward from a required heat input, operating temperature difference between sludge bed and heating medium and the heat transfer coefficient, this coefficie...

In modeling heat transfer in gas-solid processing systems, five interphase thermal processes are to be considered: gas-particle, gas-wall, particle-particle, particle-wall and wall-environment. In systems with intensive motion of particles, the particle-particle and particle-wall heat transfers occur through inter-particle and particle-wall collisions so that both experimental and modeling stud...

The optimal shape of a two dimensional turbulator above an isothermal flat plate is found by using numerical simulation. The turbulent boundary layer over the flat plate was disrupted at various situations by inserting a quadrilateral bar where the boundary layer thickness kept more than three times greater than the insert\'s height. As a result, the overall heat transfer coefficient of the wal...

in this work, three-dimensional turbulent forced convection flow through a b-type section pipe, which porous material inserted at the bottom wall, is investigated numerically. the b-type section pipe are used in cooling systems, such as cars’ radiators. the main purpose of this research is to enhance heat transfer and to reduce the scales of such systems. the governing equations are formulated ...

The Chinese high temperature gas-cooled reactor pebble bed module (HTR-PM) demonstration project has attracted increasing attention. In order to support the project, a large-scale heat transfer test facility has been constructed for pebble bed effective thermal conductivity measurement over the whole temperature range (0~1600 ◦C). Based on different heat transfer mechanisms in the randomly pack...

in this study, thermal performance of a cylindrical heat pipe is investigated numerically. three different types of water based nanofluids, namely (al2o3+water), (diamond+water) and (multi-wall carbon nano tube (mwcnt) +water) have been used. the influence of using the simple nanofluids and mwcnt nanofluid on the heat pipe characteristics such as liquid velocity, pressure profile, temperature p...

The transient preheating process of a regenerative oxidation bed placed in a coal mine methane thermal reverse-flow reactor is numerically investigated in this paper. The regenerative oxidation bed is heated by the burned gas which is generated from a burner and is distributed through manifolds, which is modeled in a three-dimensional, unsteady state and laminar flow system, and is assumed as a...