The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Seyed Soheil Mousavi Ajarostaghi - One of the best experts on this subject based on the ideXlab platform.
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Thermal mixing, cooling and entropy generation in a micromixer with a Porous Zone by the lattice Boltzmann method
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: Seyed Soheil Mousavi Ajarostaghi, Mojtaba Aghajani Delavar, Sébastien PoncetAbstract:Short transport paths with high surface to volume ratios in microfluidic devices have the potential to increase the heat transfer significantly. However, because of the very low Reynolds numbers reached in microchannel flows, it is difficult to achieve effective thermal mixing. Microfluidic mixing requires fast mixing process of low diffusivity fluids. To obtain a rapid thermal mixing in passive micromixers, a Porous block may be inserted to enhance the thermal performance. A 2D lattice Boltzmann thermal model is utilized here to investigate the thermal performance of a Y-micromixer with a Porous block. Different parameters of Porous block including its aspect ratio, its position, its porosity and its effective thermal conductivity are considered. The thermal mixing and cooling of two miscible fluids at 50 and 25 °C entering the micromixer are investigated in detail. The results show that the Porous block significantly improves the thermal mixing of both streams. Increasing the Porous block aspect ratio leads to better cooling, low entropy generation and high dimensionless entropy generation. It is also observed that thermal mixing and cooling performance increase by decreasing the effective thermal conductivity and porosity of the block, which causes a low entropy generation.
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Experiments on mist flow and heat transfer in a tube fitted with Porous media
International Journal of Thermal Sciences, 2019Co-Authors: Shahram Baragh, Hossein Shokouhmand, Seyed Soheil Mousavi AjarostaghiAbstract:Abstract The issues related to Porous media are more important in the design and analysis of heat exchangers. Reducing size of heat transfer devices for using of this media was led to be feasible of creating flow with smaller Reynolds numbers. In present study, an experimental investigation of air mist flow is carried out in tube which fitted with Porous media. The studied Porous region has different geometry. Also the effect of operating parameter like Reynolds number is analyzed. Results indicate that presence of Porous media leads that the thermal flux applied to walls of channel be transferred into fluid due to creating a uniform space and high conductivity of Porous media. Also, the results depicted that in comparison with the single-phase, mist cooling in Porous media can increase the heat transfer rate. Results show that combine these two method (Porous medium and mist flow) has significant effect on heat transfer enhancement. According to obtained results, at low Reynolds number with mist flow, the case that Porous Zone inserted adjacent to wall with 4 cm height has best thermal performance and at high Reynolds number with mist flow, highest thermal performance is belonging to the case that Porous Zone inserted at the center of the channel with 6 cm diameter. As a final result, between the all investigated models, the case that Porous Zone inserted at the center of the channel with 6 cm diameter with mist flow has the best heat transfer performance ratio with 24% improvement in comparison with clear channel.
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An experimental investigation on forced convection heat transfer of single-phase flow in a channel with different arrangements of Porous media
International Journal of Thermal Sciences, 2018Co-Authors: Shahram Baragh, Hossein Shokouhmand, Seyed Soheil Mousavi Ajarostaghi, Mohammad NikianAbstract:Abstract Nowadays, heat transfer in Porous Zone plays an important role in many industrial and modern applications. For this reason, issues related to Porous media are important in the design and analysis of heat exchangers. In this study, a single-phase flow of air in channel having circle cross-section with different arrangements of Porous media is experimentally studied. Changes in hydrodynamic parameters, improvement of heat transfer by Porous media in the channel as well as pressure drop resulted from Porous media are considered. Results from these experiments show that presence of Porous media leads that the thermal flux applied to walls of channel be transferred into fluid due to creating a uniform space and high conductivity of Porous media. Also, the mean temperature of the fluid increases and this leads to decrease temperature difference between channel wall and the mean temperature of the fluid. Because of the heat transfer coefficient has an inverse relationship with the temperature difference between the walls of the channel and the mean temperature of the fluid, the heat transfer coefficient increases. For investigation the heat transfers with pressure drop simultaneously, heat transfer performance ratio and heat transfer enhancement ratio are defined. The results of this study show that fully filled channel of Porous media has the best heat transfer enhancement (in both laminar and turbulent flows). In turbulent flow, channel with annulus shape Porous Zones (the Porous Zone inserted adjacent to wall) has the best thermal performance that means has the large value of heat transfer with low pressure drop.
Mohammed Amine Kendouci - One of the best experts on this subject based on the ideXlab platform.
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simulation of water filtration in Porous Zone based on darcy s law
Energy Procedia, 2013Co-Authors: Mohammed Amine Kendouci, Benali Kharroubi, Rachid Khelfaoui, Ali Bendida, Brahim Dennai, A MaazouziAbstract:Abstract Modeling of water filtration through a Porous Zone subjected to a steady flow with free surface. Under certain assumptions, it is possible to use a predictive process for understanding the mechanisms of filtration of water in a Porous Zone such as sand dune. The approach is based on the formulation of Darcy Porous Zone-grained. We examined the validity of Darcy model with the experimental results of a test bench realized in the laboratory. This work was done using the software Fluent family CFD (computational fluid dynamics), which is a commercial code programmed in C and based on the numerical method of finite volumes. For numerical modeling was used both CFD softwares: Gambit (the mesh) and Fluent (solver and postproceseur). Gambit and Fluent are software simulations for 2D or 3D fluid mechanics from the construction of the mesh with Gambit in solving Navier-Stokes equations and post-processing with Fluent. The experimental device used for the testing of filtration. The driver is a glass column of 5 cm diameter and 100 cm height and cylindrical shape. The effective height of the filter bed 60 cm, 30 cm is used for filtered water which is kept constant throughout the experiment, the results obtained noted that the difference between the experimental and simulated flow is order of 10-4. The results allow us to conclude that the filtration rate at operating pressure depends on the turbidity of the water directly affects the porosity of the filter and consequently its permeability.
Ilsoon Lee - One of the best experts on this subject based on the ideXlab platform.
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Development of Layered Multiscale Porous Thin Films by Tuning Deposition Time and Molecular Weight of Polyelectrolytes.
Macromolecular rapid communications, 2015Co-Authors: Oishi Sanyal, Andrew P. Izbicki, Ilsoon LeeAbstract:This work focuses on the design of Porous polymeric films with nano- and micro-sized pores existing in distinct Zones. The Porous thin films are fabricated by the post-treatment of layer-by-layer assembled poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA) multilayers. In order to improve the processing efficiency, the deposition time is shortened to ≈ 10 s. It is found that fine Porous structures can be created even by significantly reducing the processing time. The effect of using polyelectrolytes with widely different molecular weights is also studied. The pore size is increased by using high molecular weight PAH, while high molecular weight PAA minimizes the pore size to nanometer scale. Having gained a precise control over the pore size, layered multiscale Porous thin films are further built up with either a microsized Porous Zone on top of a nanosized Porous Zone or vice versa.
A Maazouzi - One of the best experts on this subject based on the ideXlab platform.
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simulation of water filtration in Porous Zone based on darcy s law
Energy Procedia, 2013Co-Authors: Mohammed Amine Kendouci, Benali Kharroubi, Rachid Khelfaoui, Ali Bendida, Brahim Dennai, A MaazouziAbstract:Abstract Modeling of water filtration through a Porous Zone subjected to a steady flow with free surface. Under certain assumptions, it is possible to use a predictive process for understanding the mechanisms of filtration of water in a Porous Zone such as sand dune. The approach is based on the formulation of Darcy Porous Zone-grained. We examined the validity of Darcy model with the experimental results of a test bench realized in the laboratory. This work was done using the software Fluent family CFD (computational fluid dynamics), which is a commercial code programmed in C and based on the numerical method of finite volumes. For numerical modeling was used both CFD softwares: Gambit (the mesh) and Fluent (solver and postproceseur). Gambit and Fluent are software simulations for 2D or 3D fluid mechanics from the construction of the mesh with Gambit in solving Navier-Stokes equations and post-processing with Fluent. The experimental device used for the testing of filtration. The driver is a glass column of 5 cm diameter and 100 cm height and cylindrical shape. The effective height of the filter bed 60 cm, 30 cm is used for filtered water which is kept constant throughout the experiment, the results obtained noted that the difference between the experimental and simulated flow is order of 10-4. The results allow us to conclude that the filtration rate at operating pressure depends on the turbidity of the water directly affects the porosity of the filter and consequently its permeability.
Mustafa M. Aral - One of the best experts on this subject based on the ideXlab platform.
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Effect of Porous Baffles on the Energy Performance of Contact Tanks in Water Treatment
Water, 2018Co-Authors: Mehmet Anil Kizilaslan, Ender Demirel, Mustafa M. AralAbstract:Three-dimensional numerical simulations are performed to evaluate the effect of Porous baffles on the efficiency of water treatment contact tanks. A second-order accurate numerical model is employed for the solutions of unsteady flow and tracer transport through the Porous baffles. The flow through the Porous medium is characterized while using the Darcy-Forchheimer relationship. Large Eddy Simulation (LES) model is used to simulate the instantaneous mixing of the tracer in the chambers of the contact tank. Three different porosities are considered to evaluate the effect of porosity on the hydraulic and mixing efficiencies of the contact tank. Simulated time-averaged flow field shows that Porous baffles that are placed at the entrance of each chamber could successfully mitigate short-circuiting and yield plug-flow conditions through the system for low porosities. Flow in the contact tank becomes laminar as the flow velocities decrease due to viscous effects and inertial resistance in the Porous Zone. For this case, the tracer is transported with bulk flow through the system and leaves the contact tank with a high peak seen in the Residence Time Distribution (RTD) plot. Porous layer increases the hydraulic efficiency of the conventional design from “poor” to “good” according to the baffling factor and increases the overall efficiency from “compromising” to “good” according to the AD index. Comparison of the performance of the Porous layer with the previously developed slot-baffle design shows that the slot-baffle design increases the efficiency of the tank with increasing dispersion effects, whereas the Porous design increases hydraulic efficiency and reduces the dispersion effects. While the Porous design reduces energy efficiency by 33% due to a drastic increase in drag in the flow through Porous Zone, the slot-baffle design increases the energy efficiency of the conventional design by 67%.