Micromixer is a significant component of microfluidics particularly in lab-on-chip applications so that there has been a growing need for design and fabrication of micromixers with a shorter length and higher efficiency. Despite most of the passive micromixers that suffer from long mixing path and complicated geometry to increase the efficiency, our novel design suggests a highly efficient micr...

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...

In this study, turbulent flow around a tube bundle in non-orthogonal grid is simulated using the Large Eddy Simulation (LES) technique and parallelization of fully coupled Navier – Stokes (NS) equations. To model the small eddies, the Smagorinsky and a mixed model was used. This model represents the effect of dissipation and the grid-scale and subgrid-scale interactions. The fully coupled NS eq...

The effect of the volume flow rate of the heat transfer fluid (air) on the thermal parameters of the solar air collector with a single air pass without using fins under the absorbing plate have been investigated experimentally and theoretically. We use a new design of solar air collector which aims to optimize these parameters in the region cited above. Our solar air collector was realized at t...

in this research, the effect of bubble surface area flux, sb, and particle size on flotation rate constant, k, of pyrite (fes2) particles was studied using bubble-particle interactions. the bubble-particle collision, attachment and detachment efficiencies were calculated under different flow regimes. the k increased with increase in the collision efficiency and decrease in the detachment effici...

in this investigation, the performance of a tower for absorption of sulphur dioxide gas into calcium carbonate solution has been studied. the trays had no downcomer and the tower itself was a scaled down pilot from industrial equipment. the industrial scale tower was used for clean up of 110000 m3/hr gas using 40 m3/hr alkaline solution. the study was composed of two parts. in the first section...

The aim of this work was to investigate effect of operational parameters on the photocatalytic degradation efficiency of a solution containing C. I. Basic Blue 41 BB41 in a recirculated rectangular photoreactor irradiated with a UV light. TiO_2 nano composite film was prepared via sol-gel dip coating method. The films were characterized by X-ray diffraction XRD, transmission electron microscopy...

In an axial flow machine, fluids flow condition, that is flow pattern in a rotating flow passage changes its form and magnitude by the hydraulic resistance to the fluid flow in flow passage. Effect of centrifugal force becomes stronger with the increase of hydraulic resistance, and the flow rate becomes smaller. And, in the comparison of fluids flow condition among different axial flow machines...

water distribution method based on the type of water conduits can be divided into two groups, namely, open and closed systems, while on the basis of the energy of the water flow, the two groups are gravity flow and pressurized flow. open channel type conveyance and distribution is achieved by gravity and includes channels made by embankment construction, excavation, or construction of prefabric...