In order to present a new and high performance structure of PEM fuel cell and study the influence of the flow direction and distribution on the rate of reactants diffusion, three novel models of vertical reactant flow injection into the anode and cathode reaction area field have been introduced. They consist of one inlet and two inlets and also a continuous channel. The governing equations on t...

for non-darcy flow in submerged porous media a one- dimensional mathematical model has been developed. rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. in this research the focus was on the rockfill detention dams in submerged condition. the existence of overtopping rock...

1. introduction floods are among earth's most common and most destructive natural hazards. floods create geomorphic hazards via changes in sediment transport and channel configuration (e.g. channel width, lateral migration, planform changes, etc). in this context, floodplain zoning and its application in spatial planning is important in non- structural measures in order to reducing flood damage...

To simulate a new economical architecture for PEM fuel cell and investigate the effectiveness of the introduced structure on the performance, computational fluid dynamics (CFD) code is used to solve the equations for a single domain of the cell namely: the flow field, the mass conservation, the energy conservation, the species transport, and the electric/ionic fields under the assumptions of st...

In the current study, five different atomistic water models (AWMs) are implemented, In order to investigate the impact of AWMs treatment on the water velocity profile and density number. For this purpose, Molecular dynamics simulation (MDS) of Poiseuille flow in a nano-channel is conducted. Considered AWMs are SPC/E, TIP3P, TIP4P, TIP4PFQ and TIP5P. To assessment of the ability of each model in...

introduction: due to sensitiveness of flow to roughness coefficient (rc), selection of this coefficient is important in earth canals designing purposes. precision selection of this coefficient is necessary for design and operation of earthen canals purposes. overestimation of the actual amount of this coefficient will cause an underestimation for flow velocity. accordingly, sedimentation in the...

This paper applies an evolutionary algorithm, the particle swarm optimization (PSO), to design the optimum open channel section. Depth, channel side slope and bottom width are considered as the variables for rectangular, triangular and trapezoidal channels, respectively. The objective function is minimizing the construction cost of the channel section. MATLAB software is used for programming an...

Spacers are used in spiral wound and plate and frame membrane modules to create flow channels between adjacent membrane layers and mix fluid within the flow channel. Flow through the spacer has a significant beneficial impact on mixing and resulting mass transfer rates but is accompanied by an undesirable increase in pressure drop. Computational Fluid Dynamics (CFD) is a common tool used to eva...

In this research, a two-dimensional mathematical model using  turbulence model was developed in a rectangular channel with granular permeable bed. Finite volume method was used for numerical solution of governing equations. The equations considered are discretized using Hybrid difference scheme while applying SIMPLE algorithm to correct velocity components in the continuity equation. In the dev...