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Records with Subject: Modelling and Simulations
Showing records 1 to 25 of 512. [First] Page: 1 2 3 4 5 Last
Investigation of Plume Offset Characteristics in Bubble Columns by Euler−Euler Simulation
Yixuan Cheng, Qiong Zhang, Pan Jiang, Kaidi Zhang, Wei Wei
October 26, 2020 (v1)
Keywords: bubble, bubble plume, Computational Fluid Dynamics, gas–liquid flow, oscillation and offset characteristic
Based on low-cost and easy to enlarge, the bubble column device has been widely concerned in chemical industry. This paper focuses on bubble plumes in laboratory-scale three-dimensional rectangular air-water columns. Static behavior has been investigated in many experiments and simulations, and our present investigations consider the dynamic behavior of bubble plume offset in three dimensions. The investigations are conducted with a set of closure models by the Euler−Euler approach, and subsequently, literature data for rectangular bubble columns are analyzed for comparison purposes. Moreover, the transient evolution characteristics of the bubble plume in the bubble column and the gas phase distribution in sections are introduced, and the offset characteristics and the oscillation period of the plume are analyzed. In addition, the distributions of the vector diagram of velocity and vortex intensity in the domain are given. The effects of different fluxes and column aspect ratios on bub... [more]
Mathematical Modeling and Stability Analysis of a Two-Phase Biosystem
Milen Borisov, Neli Dimitrova, Ivan Simeonov
October 26, 2020 (v1)
Keywords: anaerobic digestion, equilibrium points, Hydrogen, mathematical model, methane, numerical simulation, stability analysis, two-phases process
We propose a new mathematical model describing a biotechnological process of simultaneous production of hydrogen and methane by anaerobic digestion. The process is carried out in two connected continuously stirred bioreactors. The proposed model is developed by adapting and reducing the well known Anaerobic Digester Model No 1 (ADM1). Mathematical analysis of the model is carried out, involving existence and uniqueness of positive and uniformly bounded solutions, computation of equilibrium points, investigation of their local stability with respect to practically important input parameters. Existence of maxima of the input−output static characteristics with respect to hydrogen and methane is established. Numerical simulations using a specially elaborated web-based software environment are presented to demonstrate the dynamic behavior of the model solutions.
Dust Suppression Analysis of a New Spiral Hopper Using CFD-DEM Simulations and Experiments
Jianming Yuan, Chenglong Jin, Fangping Ye, Zhihui Hu, Huozhi Chen
October 26, 2020 (v1)
Keywords: CFD-DEM coupling, dust suppression, experiment, spiral hopper
A new dust suppression hopper with a spiral guide plate embedded in the conventional hopper is proposed for the dust suppression of hopper transfer processes in this article. The Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) coupling numerical method is used to investigate the particle motion and flow field distribution of the hopper transfer process. The experiment is undertaken to determine dust suppression performance. The results show that the maximum particle velocity for the spiral hopper is dropped by 1.6 m/s compared to the conventional hopper, which means the collision of the particles and the spiral hopper is weakened. The axial airflow velocity of the spiral is reduced. In addition, the maximum dust concentration of the spiral hopper inlet is reduced by 56.9% due to the impact velocity of particles is small, and the secondary fugitive dust is controlled inside a semi-closed space formed by the spiral guide plate. It is thus concluded that the spiral hopper p... [more]
Mathematical Model Describing HIV Infection with Time-Delayed CD4 T-Cell Activation
Hernán Darío Toro-Zapata, Carlos Andrés Trujillo-Salazar, Edwin Mauricio Carranza-Mayorga
October 26, 2020 (v1)
Keywords: delay differential equations, HIV, immune system, mathematical model
A mathematical model composed of two non-linear differential equations that describe the population dynamics of CD4 T-cells in the human immune system, as well as viral HIV viral load, is proposed. The invariance region is determined, classical equilibrium stability analysis is performed by using the basic reproduction number, and numerical simulations are carried out to illustrate stability results. Thereafter, the model is modified with a delay term, describing the time required for CD4 T-cell immunological activation. This generates a two-dimensional integro-differential system, which is transformed into a system with three ordinary differential equations. For the new model, equilibriums are determined, their local stability is examined, and results are studied by way of numerical simulation.
Compartment Model of Mixing in a Bubble Trap and Its Impact on Chromatographic Separations
Jürgen Beck, William Heymann, Eric von Lieres, Rainer Hahn
October 26, 2020 (v1)
Keywords: extra-column dispersion, Fluid Dynamics, mechanistic modelling, peak broadening, preparative chromatography
Chromatography equipment includes hold-up volumes that are external to the packed bed and usually not considered in the development of chromatography models. These volumes can substantially contribute to band-broadening in the system and deteriorate the predicted performance. We selected a bubble trap of a pilot scale chromatography system as an example for a hold-up volume with a non-standard mixing behavior. In a worst-case scenario, the bubble trap is not properly flushed before elution, thus causing the significant band-broadening of the elution peak. We showed that the mixing of buffers with different densities in the bubble trap device can be accurately modeled using a simple compartment model. The model was calibrated at a wide range of flow rates and salt concentrations. The simulations were performed using the open-source software CADET, and all scripts and data are published with this manuscript. The results illustrate the importance of including external holdup volumes in ch... [more]
Finite Element Analysis on Bingham−Papanastasiou Viscoplastic Flow in a Channel with Circular/Square Obstacles: A Comparative Benchmarking
Asif Mehmood, Waqar A. Khan, Rashid Mahmood, Khalil Ur Rehman
October 26, 2020 (v1)
Keywords: Bingham fluid, drag and lift coefficients, LBB-stable finite element pair, yield stress
A CFD (computational fluid dynamics) analysis was carried out for the Bingham viscoplastic fluid flow simulations around cylinders of circular and square shapes. The governing equations in space were discretized with the finite element approach via a weak formulation and utilizing Ladyzhenskaya−Babuška−Brezzi-stable pair Q 2 / P 1 disc for approximation of the velocity and pressure profiles. The discrete non-linear system was linearized through Newton’s method, and a direct linear solver was iterated as an inner core solver. The study predicts the functional dependence and impact of Bingham number, B n , on the drag coefficient and lift coefficient. The effect of the shape of an obstacle is also provided by providing comparative data for the hydrodynamic forces with the published results.
Modeling the Effect of Channel Tapering on the Pressure Drop and Flow Distribution Characteristics of Interdigitated Flow Fields in Redox Flow Batteries
Pablo A. García-Salaberri, Tugba Ceren Gokoglan, Santiago E. Ibáñez, Ertan Agar, Marcos Vera
October 26, 2020 (v1)
Keywords: channel tapering, flow distribution, interdigitated flow field, lubrication theory, Modelling, pressure drop, redox flow battery
Optimization of flow fields in redox flow batteries can increase performance and efficiency, while reducing cost. Therefore, there is a need to establish a fundamental understanding on the connection between flow fields, electrolyte flow management and electrode properties. In this work, the flow distribution and pressure drop characteristics of interdigitated flow fields with constant and tapered cross-sections are examined numerically and experimentally. Two simplified 2D along-the-channel models are used: (1) a CFD model, which includes the channels and the porous electrode, with Darcy’s viscous resistance as a momentum sink term in the latter; and (2) a semi-analytical model, which uses Darcy’s law to describe the 2D flow in the electrode and lubrication theory to describe the 1D Poiseuille flow in the channels, with the 2D and 1D sub-models coupled at the channel/electrode interfaces. The predictions of the models are compared between them and with experimental data. The results s... [more]
Experimental and Numerical Investigation of the Air Side Heat Transfer of a Finned Tubes Heat Exchanger
Máté Petrik, Gábor Szepesi
October 26, 2020 (v1)
Keywords: Computational Fluid Dynamics, finned tube, heat transfer
The heat transfer was experimentally and numerically studied in this article. Characteristics of circular fins over a bent tube at different tube orientations and air velocities were investigated, and then compared with analytical results from the literature. For the experimental investigation, a simple setup was compiled inside of a wind tunnel, where the velocity and the inlet temperature of the air; the volume flow rate; and the inlet and outlet temperatures of the water were measured. Three different orientations were investigated with the set-up: the bent tube in line with the air flow with the same and opposite water inlet positions, and the bent tube perpendicular to the air flow. According to the results, the position has a significant effect on the heat transfer coefficient. A numerical study was also performed in accordance with the measurements in ANSYS-CFX computational fluid dynamics (CFD) software. The results of the CFD showed an acceptable correlation with the results o... [more]
On the Impacts of Pre-Heated Natural Gas Injection in Blast Furnaces
Tyamo Okosun, Samuel Nielson, John D’Alessio, Shamik Ray, Stuart Street, Chenn Zhou
October 26, 2020 (v1)
Keywords: blast furnace, combustion, Computational Fluid Dynamics, fuel injection, Natural Gas, numerical simulation, RAFT
During recent years, there has been great interest in exploring the potential for high-rate natural gas (NG) injection in North American blast furnaces (BFs) due to the fuel’s relatively low cost, operational advantages, and reduced carbon footprint. However, it is well documented that increasing NG injection rates results in declining raceway flame temperatures (a quenching effect on the furnace, so to speak), with the end result of a functional limit on the maximum injection rate that can be used while maintaining stable operation. Computational fluid dynamics (CFD) models of the BF raceway and shaft regions developed by Purdue University Northwest’s (PNW) Center for Innovation through Visualization and Simulation (CIVS) have been applied to simulate multi-phase reacting flow in industry blast furnaces with the aim of exploring the use of pre-heated NG as a method of widening the BF operating window. Simulations predicted that pre-heated NG injection could increase the flow of sensib... [more]
A Detailed Mathematical Model for Evaluation of Solid Oxide Fuel Cells Performance Degradation
Mina Naeini, James S. Cotton, Thomas A. Adams II
October 14, 2020 (v1)
Keywords: Degradation rate, Long-term performance, Optimal operation, SOFCs
The performance of Solid Oxide Fuel Cells (SOFCs) degrades due to various reactions. Lack of a general model based on these reactions that predicts SOFCs long-time performance with few assumptions, limits commercialization of SOFCs. In this work, a detailed mathematical model is constructed to evaluate SOFCs long-term performance with regard to operating conditions. Most of the reactions that greatly deteriorates SOFCs components; such as Ni coarsening and oxidation, anode pore diameter changes, deterioration of anode conductivity and electrolyte conductivity, and sulfur poisoning are considered in this model to ensure that it yields reliable and precise results. A broad literature survey indicated that previously developed models only account for a part of these reactions and hence they do not provide accurate results. Rest of the models, on the other hand, are regression models that have been fitted to experimental data and thus are valid in a limited range of operating parameters.... [more]
Modelling of a Single Passage Air PV/T Solar Collector: Experimental and Simulation Design
Noran Nur Wahida Khalili, Mahmod Othman, Mohd Nazari Abu Bakar, Lazim Abdullah
October 6, 2020 (v1)
Keywords: 1D steady-state, photovoltaic/thermal, single pass, solar collector
The hybrid photovoltaic/thermal solar collector has attracted research attention for more than five decades. Its capability to produce thermal energy simultaneously with electrical energy is considered attractive since it provides higher total efficiency than stand-alone photovoltaic or thermal systems separately. This paper describes theoretical and experimental studies of a finned single pass air-type photovoltaic/thermal (PV/T) solar collector. The performance of the system is calculated based on one dimensional (1D) steady-state analysis using one dimensional energy balance equations, where simulation was carried out using MATLAB. Experiments were carried out to observe the performance of the solar collector under changes in air mass flow rate. Experimental values on photovoltaic panel temperature and air temperature on both air inlet and outlet, together with the ambient temperature and solar radiation were measured. The simulation results were validated against the results obtain... [more]
Dynamic Characteristics and Wall Effects of Bubble Bursting in Gas-Liquid-Solid Three-Phase Particle Flow
Jianfei Lu, Tong Wang, Lin Li, Zichao Yin, Ronghui Wang, Xinghua Fan, Dapeng Tan
October 6, 2020 (v1)
Keywords: bubble burst, gas-liquid-solid three-phase particle flow, micro-jet, PLIC-VOF, wall effect
The bubble bursting process existing in the particle flow is a complex gas-liquid-solid three-phase coupling dynamic problem. The bubble bursting mechanism, including dynamic characteristics and wall effects, is not clear. To address the above matters, we present a modeling method for the piecewise linear interface calculation-volume of fluid (PLIC-VOF) based bubble burst. The bubble bursting process near or on the wall is analyzed to reveal the dynamic characteristics of bubble bursting and obtain the effect of a bubble bursting on the surrounding flow field. Then a particle image velocimetry (PIV) based self-developed experimental observation platform is established, and the effectiveness of the proposed method is verified. Research results indicate that, in the high-speed turbulent environment, a large pressure difference existed in the bubble tail, which induces the bubble burst to occur; the distance between the wall and the bubble decreases; the higher the flow velocity is, the l... [more]
Geological Risk Calculation through Probability of Success (PoS), Applied to Radioactive Waste Disposal in Deep Wells: A Conceptual Study in the Pre-Neogene Basement in the Northern Croatia
Tomislav Malvić, Maria Alzira Pimenta Dinis, Josipa Velić, Jasenka Sremac, Josip Ivšinović, Marija Bošnjak, Uroš Barudžija, Želimir Veinović, Hélder Fernando Pedrosa e Sousa
October 6, 2020 (v1)
Keywords: geological risk, northern Croatia, pre-Neogene basement, probability of success (PoS), radioactive waste disposal
The basic principles of geological risk calculation through probability of success (PoS) are mostly applied to numerical estimation of additional hydrocarbon existence in proven reservoirs or potential hydrocarbon discoveries in selected geological regional subsurface volumes. It can be adapted and validated for a comprehensive input dataset collected in the selected petroleum province, by dividing up geological events into several probability categories and classes. Such methodology has been widely developed in the last decades in the Croatian subsurface—mostly in the Croatian Pannonian Basin System (CPBS). Through the adaptation of geological categories, it was also applied in hybrid, i.e., stochastic, models developed in the CPBS (Drava Depression), mostly for inclusion of porosity values. As the robustness of this methodology is very high, it was also modified to estimate the influence of water-flooding in increasing oil recovery in some proven Neogene sandstone reservoirs in the C... [more]
Physical and Mathematical Modelling of Mass Transfer in Ladles due to Bottom Gas Stirring: A Review
Alberto N. Conejo
October 6, 2020 (v1)
Keywords: kinetic models, mass transfer coefficient, mathematical modeling, mixing time, physical modeling
Steelmaking involves high-temperature processing. At high temperatures mass transport is usually the rate limiting step. In steelmaking there are several mass transport phenomena occurring simultaneously such as melting and dissolution of additions, decarburization, refining (De-P and De-S), etc. In ladle metallurgy, refining is one of the most important operations. To improve the rate of mass transfer bottom gas injection is applied. In the past, most relationships between the mass transfer coefficient (mtc) and gas injection have been associated with stirring energy as the dominant variable. The current review analyzes a broad range of physical and mathematical modeling investigations to expose that a large number of variables contribute to define the final value of the mtc. Since bottom gas injection attempts to improve mixing phenomena in the whole slag/steel system, our current knowledge shows limitations to improve mixing conditions in both phases simultaneously. Nevertheless, so... [more]
Application of Combined Developments in Processes and Models to the Determination of Hot Metal Temperature in BOF Steelmaking
José Díaz, Francisco Javier Fernández
September 23, 2020 (v1)
Keywords: ARIMA, BOF converter, carbon footprint, data-driven modelling, infrared thermometry, law-driven modelling, MARS, steelmaking, temperature forecasting, time series forecasting
Nowadays, the steel industry is seeking to reduce its carbon footprint without affecting productivity or profitability. This challenge needs to be supported by continuous improvements in equipment, methods, sensors and models. The present work exposes how the combined development of processes and models (CDPM) has been applied to the improvement of hot metal temperature determination. The synergies that arise when both sides of this research are simultaneously approached are evidenced. A workflow that takes into account the CDPM approach is proposed. First, a thermal model of the process is developed, making it possible to identify that hot metal temperature is a key lever for carbon footprint reduction. Then, three main alternatives for hot metal temperature determination are compared: infrared thermometry, time-series forecasting and machine learning prediction. Despite considering only few process variables, machine learning techniques succeed in extracting relevant information from... [more]
Condensate-Banking Removal and Gas-Production Enhancement Using Thermochemical Injection: A Field-Scale Simulation
Amjed Hassan, Mohamed Abdalla, Mohamed Mahmoud, Guenther Glatz, Abdulaziz Al-Majed, Ayman Al-Nakhli
September 23, 2020 (v1)
Keywords: field-scale simulation, gas recovery, thermochemical treatment, tight reservoirs
Condensate-liquid accumulation in the vicinity of a well is known to curtail gas production up to 80%. Numerous approaches are employed to mitigate condensate banking and improve gas productivity. In this work, a field-scale simulation is presented for condensate damage removal in tight reservoirs using a thermochemical treatment strategy where heat and pressure are generated in situ. The impact of thermochemical injection on the gas recovery is also elucidated. A compositional simulator was utilized to assess the effectiveness of the suggested treatment on reducing the condensate damage and, thereby, improve the gas recovery. Compared to the base case, represented by an industry-standard gas injection strategy, simulation studies suggest a significantly improved hydrocarbon recovery performance upon thermochemical treatment of the near-wellbore zone. For the scenarios investigated, the application of thermochemicals allowed for an extension of the production plateau from 104 days, as... [more]
Linking CFD and Kinetic Models in Anaerobic Digestion Using a Compartmental Model Approach
Yohannis Mitiku Tobo, Jan Bartacek, Ingmar Nopens
September 23, 2020 (v1)
Keywords: ADM1, CM, Computational Fluid Dynamics, kinetics, non-Newtonian fluid, spatial variation
Understanding mixing behavior and its impact on conversion processes is essential for the operational stability and conversion efficiency of anaerobic digestion (AD). Mathematical modelling is a powerful tool to achieve this. Direct linkage of Computational Fluid Dynamics (CFD) and the kinetic model is, however, computationally expensive, given the stiffness of the kinetic model. Therefore, this paper proposes a compartmental model (CM) approach, which is derived from a converged CFD solution to understand the performance of AD under non-ideal mixing conditions and with spatial variation of substrates, biomass, pH, and specific biogas and methane production. To quantify the effect of non-uniformity on the reactor performance, the CM implements the Anaerobic Digestion Model 1 (ADM1) in each compartment. It is demonstrated that the performance and spatial variation of the biochemical process in a CM are significantly different from a continuously stirred tank reactor (CSTR) assumption. H... [more]
3D Integrated Modeling of Supersonic Coherent Jet Penetration and Decarburization in EAF Refining Process
Yuchao Chen, Armin K. Silaen, Chenn Q. Zhou
September 23, 2020 (v1)
Keywords: Computational Fluid Dynamics, decarburization, EAF, steel refining, supersonic coherent jet
The present study proposes a complete 3D integrated model to simulate the top-blown supersonic coherent jet decarburization in the electric arc furnace (EAF) refining process. The 3D integrated model avoids the direct simulation of the supersonic coherent jet interacting with the liquid steel bath and provides a feasible way to simulate the decarburization in the liquid steel-oxygen two-phase reacting flow system with acceptable computational time. The model can be used to dynamically predict the details of the molten bath, including 3D distribution of in-bath substances, flow characteristics and bath temperature and provide a basis for optimizing the decarburization rate or other required parameters during the refining process.
Performance Assessment of SWRO Spiral-Wound Membrane Modules with Different Feed Spacer Dimensions
A. Ruiz-García, I. Nuez
September 15, 2020 (v1)
Keywords: desalination, feed spacers, membrane performance, permeability coefficients, reverse osmosis, seawater
Reverse osmosis is the leading process in seawater desalination. However, it is still an energy intensive technology. Feed spacer geometry design is a key factor in reverse osmosis spiral wound membrane module performance. Correlations obtained from experimental work and computational fluid dynamics modeling were used in a computational tool to simulate the impact of different feed spacer geometries in seawater reverse osmosis spiral wound membrane modules with different permeability coefficients in pressure vessels with 6, 7 and 8 elements. The aim of this work was to carry out a comparative analysis of the effect of different feed spacer geometries in combination with the water and solute permeability coefficients on seawater reverse osmosis spiral wound membrane modules performance. The results showed a higher impact of feed spacer geometries in the membrane with the highest production (highest water permeability coefficient). It was also found that the impact of feed spacer geometr... [more]
A Fractal-Based Correlation for Time-Dependent Surface Diffusivity in Porous Adsorbents
Vassilis J. Inglezakis, Marco Balsamo, Fabio Montagnaro
September 15, 2020 (v1)
Keywords: Adsorption, fractal-like dynamics, hindered diffusion, hopping, surface diffusivity, zeolites
Fluid−solid adsorption processes are mostly governed by the adsorbate transport in the solid phase and surface diffusion is often the limiting step of the overall process in microporous materials such as zeolites. This work starts from a concise review of concepts and models for surface transport and variable surface diffusivity. It emerges that the phenomenon of hindered surface diffusion for monolayer adsorption, which is common in zeolites, and models able to fit a non-monotonic trend of surface diffusivity against adsorbate solid phase concentration, have received limited attention. This work contributes to the literature of hindered diffusion by formulating a time-dependent equation for surface diffusivity based on fractal dynamics concepts. The proposed equation takes into account the contributions of both fractal-like diffusion (a time-decreasing term) and hopping diffusion (a time-increasing term). The equation is discussed and numerically analyzed to testify its ability to rep... [more]
Air-Forced Flow in Proton Exchange Membrane Fuel Cells: Calculation of Fan-Induced Friction in Open-Cathode Conduits with Virtual Roughness
Dejan Brkić, Pavel Praks
September 15, 2020 (v1)
Keywords: Colebrook equation, flow friction factor, Fuel Cells, numerically stabile solution, open-cathode, pressure drop, roughness, symbolic regression
Measurements of pressure drop during experiments with fan-induced air flow in the open-cathode proton exchange membrane fuel cells (PEMFCs) show that flow friction in its open-cathode side follows logarithmic law similar to Colebrook’s model for flow through pipes. The stable symbolic regression model for both laminar and turbulent flow presented in this article correlates air flow and pressure drop as a function of the variable flow friction factor which further depends on the Reynolds number and the virtual roughness. To follow the measured data, virtual inner roughness related to the mesh of conduits of fuel cell used in the mentioned experiment is 0.03086, whereas for pipes, real physical roughness of their inner pipe surface goes practically from 0 to 0.05. Numerical experiments indicate that the novel approximation of the Wright-ω function reduced the computational time from half of a minute to fragments of a second. The relative error of the estimated friction flow factor is les... [more]
Accuracy Assessment of RANS Predictions of Active Flow Control for Hydrofoil Cavitation
Chandra Shekhar Pant, Yann Delorme, Steven Frankel
August 29, 2020 (v1)
Keywords: cavitation control, hydrodynamic performance, OpenFOAM
In this work, we numerically investigate the cavitating flow on the scaled-down 2D model of guided vanes. Furthermore, the effects of wall injection on both the cavitation and on the hydrodynamic performance of the guided vane are studied. The numerical simulations are performed using OpenFOAM v1906. We used a 2D k- ω SST model for modeling the turbulence in the present set of simulations. We studied the flow for two angles of attack, viz. 3 ∘ and 9 ∘ . For the 3 ∘ angle of attack, the present numerical work is in good agreement with the previous experimental work, but for the larger angle of attack, because of flow separation, the present simulations do not capture the flow correctly.
Considering the Diffusive Effects of Cavitation in a Homogeneous Mixture Model
Yanghui Ye, Cong Dong, Zhiguo Zhang, Yangyang Liang
August 29, 2020 (v1)
Keywords: cavitation, constant-transfer coefficient, diffusion, homogeneous mixture
Homogeneous mixture models are widely used to predict the hydrodynamic cavitation. In this study, the constant-transfer coefficient model is implemented into a homogeneous cavitation model to predict the heat and mass diffusion. Modifications are made to the average bubble temperature and the Peclet number for thermal diffusivity in the constant-transfer coefficient model. The evolutions of a spherical bubble triggered by negative pressure pulse are simulated to evaluate the prediction of heat and mass diffusion by the homogeneous model. The evolutions of three bubbles inside a rectangular tube are simulated, which show good accuracy of the homogeneous model for multibubbles in stationary liquid.
An Analytical Model to Predict the Effects of Suspended Solids in Injected Water on the Oil Displacement Efficiency during Waterflooding
Slavko Nesic, Anatoly Zolotukhin, Vladimir Mitrovic, Dragan Govedarica, Afshin Davarpanah
August 29, 2020 (v1)
Keywords: formation damage, oil displacement, suspended solids, waterflooding
Suspended solids in the injection water cause impairment of water injectivity during waterflooding operations. Suspended solids affect reservoir properties and decrease the permeability of reservoir rocks causing an increase of injection pressure and a decrease in water injectivity. Removal of all suspended solids from injection water is an expensive and economically unfeasible process. To minimize the effects of suspended solids to the formation, it is necessary to determine an impairment mechanism of suspended solids on oil displacement and, therefore, optimize the water treatment process. In this paper, an analytical model that describes the relationship between injection water quality and impairment mechanisms on oil displacement is presented. A formation impairment was calculated, introducing the parameter called impairment ratio, which represents the ratio between suspended solids and pore size distribution of reservoir rock. Based on the impairment ratio, decreases in porosity a... [more]
Numerical Modeling and Analysis of the Performance of an Aluminum-Air Battery with Alkaline Electrolyte
Jiadong Xie, Pan He, Ruijie Zhao, Jianhong Yang
August 29, 2020 (v1)
Keywords: aluminum-air battery, battery performance, electrochemistry, fuel cell, numerical simulation
A numerical model is created to simulate the discharge performance of aluminum-air batteries (AABs) with alkaline electrolyte. The discharge voltage and power density, as a function of the discharge current density, are predicted for the modeled AAB and compared with experimental measurements. A good agreement between model and experiment is found. The effect of various model parameters on the battery performance is studied by adjusting the parameters within a suitable range. The results show that electrolyte thickness is a key factor that can strongly increase the power density and the corresponding current density as the electrolyte thickness decreases. The peak of power density is increased by a factor of two if the electrolyte thickness is reduced from 7 mm to 3 mm. The alkaline concentration is also an important factor, since both the voltage and power density curves are significantly raised as the NaOH concentration is increased from 1 to 4 mol/L. The partial oxygen pressure play... [more]
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