effect of methanol concentration and channel depth of bipolar plates on the performance of single direct methanol fuel cell was investigated experimentally. the membrane used in this experiment was nafion117. dimension of the single cell were 10cm 10 cm. methanol concentrations of 0.50, 1.0, 1.5, 2.0, 3.0 molar were used. channel depth of the bipolar plates were chosen to be 1.0, 1.5, 2.0 mm, a...

a numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. the continuity and momentum equations were solved first, assuming the wall reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. the results show that at constant inlet and...

most previous laboratory studies of local scour at bridge abutments were performed in rectangular channels in which the distributions of flow velocity and bed shear stress were considered uniform in the transverse direction. in reality however, bridge abutments are usually located in the floodplain zone of rivers where velocity and shear stress distributions are directly affected by the lat...

the study of flow in compound channels with vegetated floodplains is essential to assessing the development of the stage-discharge relationship and sediment and pollutant transport. the present study experimentally investigated mean flow and turbulence characteristics in a prismatic compound channel. the experimental program consisted of vegetated and non-vegetated floodplains with different re...

Experiments are conducted with a perfluorinated dielectric fluid, Fluorinert FC-77, to investigate the effects of channel width, depth, and aspect ratio on flow boiling heat transfer and flow patterns in microchannels. Experiments are performed for a fixed mass flux of 630 kg/ms with eleven different silicon test pieces containing parallel microchannels of widths ranging from 100 μm to 5850 μm ...

Heat transfer with liquid–vapor phase change in microchannels can support very high heat fluxes for use in applications such as the thermal management of high-performance electronics. However, the effects of channel cross-sectional dimensions on the two-phase heat transfer coefficient and pressure drop have not been investigated extensively. In the present work, experiments are conducted to inv...

In recent years, impinging streams have received increasing interest for their high efficiency in heat and mass transfer. This numerical study was conducted to investigate flow and heat transfer characteristics of one-way opposing jets of non-Newtonian fluids. Effects of Reynolds number impinging angle, momentum ratio and flow behavior index on mixing index were evaluated. The results showed im...