One of the effective methods to improve the thermal efficiency of solar collectors is using nanofluids as the coolant. The present study experimentally investigated the effect of SiO2/water nanofluid with 1% mass fraction on the performance of a symmetric collector, i.e. conical solar collector. The conical solar collector with 1 m2 area and normal to the earth was tested in Ahvaz, a city in th...

Shoulder geometry of tool plays an important role in friction-stir welding because it controls thermal interactions and heat generation. This work is proposed and developed a coupled rigid-viscoplastic numerical modeling based on computational fluid dynamics and finite element calculations aiming to understand these interactions. Model solves mass conservation, momentum, and energy equations in...

Unsteady slip-flow of second grade non-Newtonian electrically conducting fluid over an oscillating sheet has been considered and solved numerically. A second-order slip velocity model is used to predict the flow characteristic past the wall. With the assumption of infinite length in x-direction, velocity of the fluid can be assumed as a function of y and t, hence, with proper variable change pa...

a thermodynamic analysis of the counter flow wet cooling tower (cwct) in the steelmaking unit of the khuzestan steel company (ksc) is performed in this paper. we evaluated both energy and exergy formulations for analyzing the heat and mass transfer, exergy and second-law efficiency in this cooling tower. the lewis factor le f is an indication of the relative rates of heat and mass transfer in a...

in this research a flat plate solar air collector was investigated under direct solar radiation consisted of a slatted glass cover, perforated absorber aluminum sheets (porosity 0.0177, 0.0314 and absorber thickness of 2.5 mm). the effect of porosity on absorber efficiency of collector was evaluated. six levels of air mass flow rates (0.0056 to 0.0385 kg m-2 s-1) were adopted.average solar ener...