The use of an artificial roughness on a surface of absorber plate is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. This paper presents a comparison of parameters that enhance the heat transfer coefficient thus efficiency ofa solar air heater for different artificially roughened geometries for the Reynolds number from 2500 -18000. Th...

Experimental investigations has been done to find out the heat transfer characteristics and friction factor of water based Al2O3 nanofluids as a coolant in  brazed plate heat exchanger. Plate heat exchanger either use horizontally or vertically. The base plate of the plate heat exchanger was kept inclined at (0⁰, 30⁰ ,60⁰, 90⁰). The experimentation have been done on the two different concentrat...

Nanofluids are the new generation way to enhance thermal properties of common fluids. The potential of nanofluidshave made them very useful in different heat transfer applications. In this paper, the injection velocity effects on copper nanofluids over permeable stretching/shrining surfaces are analysed in stagnation–point flow. Nanofluids are under the influence of magnetic field. The PDE gove...

the subjects of heat transfer and cooling system are very important topics in the internal combustion engines (ice). in modern cooling systems, low weight, small size and high compactness are the critical designing criteria that requires heat transfer enhancement. boiling phenomenon which is occurred in the water jacket of the ice is one of the methods to increase heat transfer in the coolant s...

A neural network correlation, RAD-NNET, is developed to simulate the realistic effect of non-gray radiative absorption by a homogeneous mixture of combustion gases (CO2 and H2O) and soot using numerical data generated by RADCAL. RAD-NNET is then applied to assess the accuracy of some commonly accepted approximate approaches to evaluate radiative heat transfer in three-dimensional non-gray media...

Many test handlers process semiconductor devices in trays which must be rapidly heated or cooled by a forced air flow to a desired test temperature and then back to ambient temperature. This paper describes a new design feature for testhandler tray that significantly increases the rate of convective heat transfer to the tray and the devices in the tray. The improved tray incorporates lateral ri...

In this work time dependent heat transfer flow through a kerosene based ferrofluid is considered. The flow is in a cylindrical geometry with the height and diameter of 10 mm. Computational fluid dynamics was used to simulate the system. In CFD simulations mixture model was applied to describe the behavior of the magnetic particles. A uniform magnetic field with different strengths and direction...

In this paper, Turbulent mixed convective heat transfer of water and Al2O3 nanofluid has been numerically studied in a horizontal tube under non-uniform heat flux on the upper wall and insulation in the lower wall using mixture model. For the discretization of governing equations, the second-order upstream difference scheme and finite volume method were used. The coupling of pressure and veloci...

In this paper, free convection flow and heat transfer of nanofluids of differently-shaped nano-sized particles over a vertical plate at very low and high Prandtl numbers are analyzed.  The governing systems of nonlinear partial differential equations of the flow and heat transfer processes are converted to systems of nonlinear ordinary differential equation through similarity transformations. T...

A comprossiblo finite voluinc fortuulalioii for largo eddy simulation IWLS been exleiuled to solve a variety of (lows by using dynamic subgrid-scale stress model and dynamic Prandtl number model. The basic features of this finite volume fornmlatioii include a dual time stepping approach with time derivative preconditioning, an implicit low-upper symtiietric Gauss-Seidel scheme, multiblock frame...