Showing papers on "Volumetric flow rate published in 2014"
TL;DR: In this paper, the concentration overpotential is modelled as a function of flow rate in an effort to determine an appropriate variable flow rate that can yield high system efficiency, along with the analysis of pressure losses and total pumping energy.
302 citations
TL;DR: In this article, a volume-of-fluid-based finite volume method was developed for simulating two-phase flow directly on micro-CT images of porous media and an analytical analysis of the relationship between the pore-scale forces and the Darcy-scale pressure drops was presented.
245 citations
TL;DR: In this article, an analytical study is performed on the entropy generation and heat transfer due to nanofluid flow in a flat plate solar collector, and the results are presented for constant mass flow rates ranging from 0.1 to 0.8 kg/s.
180 citations
TL;DR: In this article, nine flat-sheet commercially available hydrophobic PTFE membranes were used in desalination by direct contact membrane distillation and their characteristics were investigated under different operating conditions including feed temperature, feed flow rate, cold stream flow rate and feed concentration.
Abstract: In this study, nine flat-sheet commercially available hydrophobic PTFE membranes were used in desalination by direct contact membrane distillation and their characteristics were investigated under different operating conditions including feed temperature, feed flow rate, cold stream flow rate, and feed concentration. Membrane properties, i.e. pore size, thickness, support layer, and salt rejection were also studied. Moreover, membrane module designs including flow arrangements (co-current, counter-current and tangential) for process liquid and depth both on hot and cold sides were tested experimentally. Finally, the long-term performance of the selected membranes for direct contact membrane distillation as a stand-alone desalination process was investigated. The results indicated that increasing feed temperature, hot feed flow rate, and module depth on the cold side led to increase permeate flux. On the other hand, increasing membrane thickness and module depth on the hot side (at constant flow rate) had negative effects on the flux. The highest permeation flux and salt rejection was achieved when the membranes with a pore size of 0.22 μm were used in the cross-current follow arrangement of hot and cold streams. In addition, the requirements for support layer for a successful DCMD process has been extensively discussed.
155 citations
Patent•
18 Mar 2014TL;DR: In this paper, a gas distribution system, a gas-phase reactor system, and a method of using the gas distribution and the reactor system is described. But the authors do not discuss the use of the gas supply in the reaction chamber of the reactor.
Abstract: A gas distribution system, a reactor system including the gas distribution system, and method of using the gas distribution system and reactor system are disclosed. The gas distribution system can be used in gas-phase reactor systems to independently fine tune gas source locations and gas flow rates of reactants to a reaction chamber of the reactor systems.
142 citations
TL;DR: In this paper, the influence of heat and mass transfer on peristaltic flow in a non-uniform rectangular duct is studied under the consideration of long wavelength ( 0 ≪ λ → ∞ ) and low Reynolds number ( Re → 0 ).
142 citations
TL;DR: In this article, a helium plasma jet is generated by applying pulsed high voltage of 8kV with 10kV using a quartz tube with an inner diameter of 4mm.
Abstract: The atmospheric-pressure helium plasma jet is of emerging interest as a cutting-edge biomedical device for cancer treatment, wound healing and sterilization Reactive oxygen species such as OH and O radicals are considered to be major factors in the application of biological plasma In this study, density distribution, temporal behaviour and flux of OH and O radicals on a surface are measured using laser-induced fluorescence A helium plasma jet is generated by applying pulsed high voltage of 8 kV with 10 kHz using a quartz tube with an inner diameter of 4 mm To evaluate the relation between the surface condition and active species production, three surfaces are used: dry, wet and rat skin When the helium flow rate is 15 l min−1, radial distribution of OH density on the rat skin surface shows a maximum density of 12 × 1013 cm−3 at the centre of the plasma-mediated area, while O atom density shows a maximum of 10 × 1015 cm−3 at 20 mm radius from the centre of the plasma-mediated area Their densities in the effluent of the plasma jet are almost constant during the intervals of the discharge pulses because their lifetimes are longer than the pulse interval Their density distribution depends on the helium flow rate and the surface humidity With these results, OH and O production mechanisms in the plasma jet and their flux onto the surface are discussed
135 citations
TL;DR: A method that rapidly generates time-series reaction data from flow reactors by continuously manipulating the flow rate and reaction temperature has been developed and makes use of inline IR analysis and an automated microreactor system, which allowed for rapid and tight control of the operating conditions.
Abstract: Currently, kinetic data is either collected under steady-state conditions in flow or by generating time-series data in batch. Batch experiments are generally considered to be more suitable for the generation of kinetic data because of the ability to collect data from many time points in a single experiment. Now, a method that rapidly generates time-series reaction data from flow reactors by continuously manipulating the flow rate and reaction temperature has been developed. This approach makes use of inline IR analysis and an automated microreactor system, which allowed for rapid and tight control of the operating conditions. The conversion/residence time profiles at several temperatures were used to fit parameters to a kinetic model. This method requires significantly less time and a smaller amount of starting material compared to one-at-a-time flow experiments, and thus allows for the rapid generation of kinetic data.
129 citations
TL;DR: In this paper, the performance of a VRFB with flow fields is analyzed and compared with the performance without flow fields, and it is demonstrated that the battery with flow field has a higher discharge voltage at higher flow rates, but exhibits a larger pressure drop.
128 citations
TL;DR: In this paper, ellipsoidal particles were used to investigate the shape effect on granular flow in a cylindrical hopper and the results indicated that particle shape can make a significant effect on the flow pattern.
127 citations
TL;DR: In this article, a three-dimensional solid-fluid conjugated model is coupled with a simplified conjugate-gradient method to optimize the flow and heat transfer in a water-cooled, silicon-based double-layer microchannel heat sink (MCHS).
TL;DR: In this article, a liquid-liquid mass transfer between immiscible liquids using the system 1-butanol and water, with succinic acid as the mass transfer component, is presented.
TL;DR: In this article, a modified design of condenser (dehumidifier) is proposed in HDH process to evaluate the performance of the unit and the results show that the modified condenser design increases the condenser effectiveness to be about 0.71 while, for conventional type of 0.49.
01 May 2014
TL;DR: In this article, a liquid-liquid mass transfer between immiscible liquids using the system 1-butanol and water, with succinic acid as the mass transfer component, is presented.
Abstract: We address liquid–liquid mass transfer between immiscible liquids using the system 1-butanol and water, with succinic acid as the mass transfer component. Using this system we evaluate the influence of two-phase flow transitions from Taylor flow to stratified flow and further to dispersed flow at elevated flow rates. In addition, we address the scale-up behavior of mass transfer coefficients and the extraction efficiency by using reactors on the micro- and the milli-scale. Flow imaging enables us to identify the different flow regimes and to connect them to the trends observed in mass transfer, and the obtained results highlight the dependence of mass transfer on flow patterns. Furthermore, the results show that on the milli-scale fluid–structure interactions are driving the phase dispersion and interfacial mass transfer, and such a reactor design ensures straightforward scalability from the micro- to the milli-scale.
TL;DR: In this paper, a car radiator was used to enhance heat transfer with nanowders, and the results showed that the Nusselt number increased with volume flow rate and slightly increased with inlet temperature and volume concentration.
TL;DR: In this paper, the authors proposed a numerical model to simultaneously predict the fluid flow and heat transfer on both air-side and water-side of elliptical FTHE, and the results indicated that the axis ratio strongly interacts with air velocity and water volumetric flow rate.
TL;DR: In this paper, a hybrid solar desalination system consisting of a humidification-dehumidification unit and a single stage flashing evaporation unit was studied numerically, where the heat and mass transfer and flow field were modeled theoretically in two dimensions using the finite difference scheme.
TL;DR: In this article, the authors simulated turbulent and laminar flow heat transfer in nanofluids (Al2O3 particles in water and ethylene glycol-based fluid) passing through a flat tube in 3D using computational fluid dynamics (CFD) for single and two-phase approaches.
TL;DR: Molecular dynamics simulations of water flow in carbon, boron nitride, and silicon carbide nanotubes show that the flow enhancement depends on the tube's geometric characteristics and the solid-liquid interactions.
Abstract: The high water flow rates observed in carbon nanotubes (CNTs) have previously been attributed to the unfavorable energetic interaction between the liquid and the graphitic walls of the CNTs. This paper reports molecular dynamics simulations of water flow in carbon, boron nitride, and silicon carbide nanotubes that show the effect of the solid-liquid interactions on the fluid flow. Alongside an analytical model, these results show that the flow enhancement depends on the tube's geometric characteristics and the solid-liquid interactions.
TL;DR: In this article, the effect of film cooling thickness, flow rate, inlet temperature, and air wind speed on the stepped solar still daily productivity is studied. And the best combination was: film thickness from 2.5 × 10−4 to 5 × 5.8 × 4.3/s, and glass cover length from 2 to 2.8 m, cooling water volumetric flow rate from 4× 10−5 to 8.2 m.
TL;DR: In this paper, confocal microscopy was used to visualize the simultaneous flow of both a wetting and a nonwetting fluid through a model 3D porous medium, and it was shown that for small flow rates, both fluids flow through unchanging, distinct, connected 3D pathways; in contrast, at sufficiently large flow rates the non-wetting liquid is broken up into discrete ganglia.
Abstract: We use confocal microscopy to directly visualize the simultaneous flow of both a wetting and a non-wetting fluid through a model three-dimensional (3D) porous medium. We find that, for small flow rates, both fluids flow through unchanging, distinct, connected 3D pathways; in stark contrast, at sufficiently large flow rates, the non-wetting fluid is broken up into discrete ganglia. By performing experiments over a range of flow rates, using fluids of different viscosities, and with porous media having different geometries, we show that this transition can be characterized by a state diagram that depends on the capillary numbers of both fluids, suggesting that it is controlled by the competition between the viscous forces exerted on the flowing oil and the capillary forces at the pore scale. Our results thus help elucidate the diverse range of behaviors that arise in two-phase flow through a 3D porous medium.
01 Mar 2014
TL;DR: The ability to produce spherical poly(lactic-co-glycolic) acid (PLGA) particles with and without encapsulated active agent, with relative standard deviation not exceeding 15%, was demonstrated over a remarkably broad diameter range.
Abstract: This study reports on a methodology to control the size of polymer particles generated by the electrospray (ES) drying route, with emphasis on the generation of biodegradable polymer nanoparticles that are well suited for biomedical applications. The ability to produce spherical poly(lactic-co-glycolic) acid (PLGA) particles with and without encapsulated active agent, with relative standard deviation not exceeding 15%, was demonstrated over a remarkably broad (60 nm–2 μm) diameter range. By judiciously choosing ES parameters and solution properties, we can control the monodispersity and the size of the obtained particles, tailoring it to a specific application. The main parameters affecting particle size include solution electrical conductivity, flow rate and initial polymer volume fraction. Quasi-monodispersity at both the micro- and the more challenging nano-scale was achieved by avoiding Coulomb fission in the spray droplets, via entanglement of the polymer chains within the droplets rather than by charge neutralization. Guiding principles in the formulation of the solutions to satisfy a multiplicity of constraints are provided along with an extensive database of “recipes”.
TL;DR: In this article, three nanofluids comprising of aluminum oxide, copper oxide and silicon dioxide nanoparticles in ethylene glycol and water mixture have been studied theoretically to compare their performance in a compact minichannel plate heat exchanger (PHE).
TL;DR: In this article, a comparative study of the hydrodynamics of the serpentine and interdigitated flow fields has been performed, and the results show that the pressure drop in the inter-digitated field is less than that in the serranine field for the same flow rate.
Abstract: Electrolyte flow distribution is an important factor that contributes to the performance of the overall efficiency of a redox flow battery system. In the present paper, a comparative study of the hydrodynamics of the serpentine and interdigitated flow fields has been performed. Ex situ experiments were conducted using the two flow fields in conditions typical of flow battery applications. Limited in situ testing has also been conducted. These bring out the surprising result that the pressure drop in the interdigitated flow field is less than that in the serpentine for the same flow rate. Computational fluid dynamics studies show strong under-the-rib convection in the reaction zone exists in both flow fields but with a shorter residence time in case of the interdigitated. It is posited that this may explain the superior electrochemical performance of cells with interdigitated flow fields.
TL;DR: In this article, the authors present a macroscopic model of a typical PEMFC-like RFB electrode-flow field design, which is a layered system comprised of a single passage of a serpentine flow channel and a parallel underlying porous electrode (or porous layer).
TL;DR: In this paper, a predictive model is developed for the estimation of the temperature polarization coefficient across the membrane taking into consideration the simultaneous heat and mass transfer phenomena, which can be used to estimate the local flux and local temperature polarization coefficients as opposed to the methods used by others which estimate the TPC, using the average bulk temperatures.
TL;DR: In this article, the effects of the groove shape on the flow characteristics through computational fluid dynamics (CFD) and experimental investigations are clarified by comparing the computational results with the experimental data, and the discharge coefficient as a function of groove geometry, flow condition, fitting coefficients and its stable value is deduced.
TL;DR: In this paper, an air-breathing direct formic acid membraneless microfluidic fuel cell using graphite cylinder arrays as the anode is proposed and the three dimensional anode volumetrically extends the reactive surface area and improves fuel utilization.
TL;DR: In this article, two sets of experiments were carried out to further investigate the flow of emulsion in consolidated sandstone core plugs, and the pore-scale dynamics has been shown to depend on local capillary number and emulsion drop size.