most of river engineering problems are complicated and need to be analyzed by three dimensional models of flow and sediment transport. considering the fact that computers and numerical methods with great ability of flow and sediment transport simulation are developing quickly, using numerical modeling by engineers is inevitable. nevertheless, before application, numerical models need to be veri...

Most of river engineering problems are complicated and need to be analyzed by three dimensional models of flow and sediment transport. Considering the fact that computers and numerical methods with great ability of flow and sediment transport simulation are developing quickly, using numerical modeling by engineers is inevitable. Nevertheless, before application, numerical models need to be veri...

a numerical study of 3d electrokinetic flows through micromixers was performed. the micromixers considered here consisted of heterogeneous rectangular microchannels with prescribed patterns of zeta-potential at their walls. numerical simulation of electroosmotic flows within heterogeneous channels requires solution of the navier-stokes, ernest-plank and species concentration equations. it is kn...

A numerical study of 3D electrokinetic flows through micromixers was performed. The micromixers considered here consisted of heterogeneous rectangular microchannels with prescribed patterns of zeta-potential at their walls. Numerical simulation of electroosmotic flows within heterogeneous channels requires solution of the Navier-Stokes, Ernest-Plank and species concentration equations. It is kn...

The efficiency and economical performance of sewer systems is an essential issue in urban drainage. The need for sewers to carry sediment has been recognized for many years. One of the main problems in designing sewerage systems is the sediment deposition. Sedimentation in sewers occurs regularly according to the alternating natural flow. The present study investigates the hydraulic characteris...

local scouring around bridge piers is a natural phenomenon caused by the erosive process of flowing stream on alluvial beds. the 3d flow field around bridge piers interacting with the bed materials increases complexity of local scour process. the local scour depth develops in accelerated flows and if it is not predicted correctly, the bottom level of local scour hole will exceed the original le...

in the present paper, a 3d numerical model has been applied to predict the flow hydrodynamics around power intakes within the dez dam reservoir. the dez dam is a 203 m high, double arch concrete dam which is constructed by italians in 1962. since then, sedimentation in reservoirhas continued and since the dam does not have bottom outlet, the reservoir bed level is raising by a rate of about 2.5...

one of the most concerning issues for researchers is to predict the shape and dimensions of the scour pit nearhydraulic structures such as the base of bridges, weirs, valves and stilling basins due to both financial and humanhazards induced by destruction of the structure. as the scour issue has its own complexity in relation to themultiplicity of effecting factors on it, in this study therefor...

numerical investigation of 3d electrokinetic mixing through micromixer has performed both qualitatively and quantitatively. in order to reduce numerical expenses of 3d flows, we implement the helmholtz-smoluchowski method for the numerical modeling of electroosmotic flows. according to the previous study of electrokinetic mixing inside the heterogeneous microchannels, existence of the vortexes ...

mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. in this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numeri...