Nanofluids are stable suspensions of nanoparticles in conventional heat transfer fluids (base fluids) that exhibit better thermal characteristics compared to those of the base fluids. It is important to clarify various aspects of nanofluids behavior. In order to identify the thermal and hydrodynamic behavior of nanofluids flowing through non-circular ducts, in the present study the laminar flow...

entry region of a rectangular microchannel is investigated. The wall heat flux is peripherally constant and varies exponentially with respect to the axis of the microchannel. The flow is assumed to be hydrodynamically fully developed. The three-dimensional energy conservation equation is solved numerically for different aspect ratios. Surface interaction parameters consist of momentum accommoda...

In this paper conjugated heat transfer in thermal entrance region through the sinusoidal wavy channel has been investigated. The fluid flow is assumed to be laminar, steady state, incompressible, and hydrodynamically fully developed. A constant heat flux is assumed to be applied on the outer edge of the channel wall. In this study the governing equations including continuity, momentum and energ...

Heat transfer from the internal surfaces of a vertical pipe to the adjacent air gives rise to the air flow establishment within the pipe. With the aim of optimizing the convective air flow rate in a vertical pipe, the details of the flow and thermal fields were investigated in the present study. Conservation equations of mass, momentum, and energy were solved numerically using simple implicit f...

In this study, mixed convection heat transfer and local and global entropy generation in aventilated square cavity have been investigated numerically. The natural convection effect isachieved by a constant heat flux imposed at the bottom wall and cooled by injecting a coldfollow. In order to investigate the effect of port location, four different placementconfigurations of the inlet and outlet ...

A numerical study is carried out to investigate the laminar forced convection heat transfer from a circular cylinder. The fluid is assumed to be incompressible, the Reynolds number ranged from 0.1 to 1000, and the Prandtl number was equal to 0.7. The range of study includes heat transfer in creeping flow (Re40). The equations were discretized by a control-volume-based finite difference techniqu...

The effect of thermal and solutal buoyancy induced by a discrete source of heat and mass transfer in a square duct under the influence of magnetic field, especially at the turbulent regime for the first time is reported. Al2O3/water nanofluid is used with constant heat flux from three discrete heat sources. In the present study, the effects of Reynolds number (100 to 3000), particle volume frac...

an investigation on the thermal performance of the soil as geothermal heat energy storage medium has been conducted. the thermal characteristics of the soil storage and the heat transfer from a heat exchanger in the soil, surrounding and bottom surface will be discussed. this investigation forms a contribution to a project to realize such storage to be charged from a solar heating system. this ...