Records with Keyword: Computational Fluid Dynamics
Showing records 1 to 25 of 641. [First] Page: 1 2 3 4 5 Last
Reducing the Environmental and Economic Consequences of Installing an Underground Collector and Increasing User Comfort with a New Geometry and Installation Method
Ľubomíra Gabániová, Dušan Kudelas
February 10, 2024 (v1)
Keywords: Computational Fluid Dynamics, ground collector, heat extraction, renewable energy sources
The installation of ground collectors often has several disadvantages for the user, despite future benefits in more ecological heating, namely the need for a large space for installation, which increases costs, and can also cause inconvenience later, for example, by keeping snow on the surface for a longer time. The goal of this paper was to find out with the help of simulations in ANSYS whether a collector with a different geometry and arrangement (vertical spiral with diameters of 6, 8 and 10 m), which would be more comfortable, cheaper, and also friendlier to the environment, would achieve performance similar to the classic geometry—meander. The initial results are relatively favorable and prove that there is room for optimization and improvement in this field. Verification of network sensitivity in all cases is 8% or less. In the current situation of the energy crisis, it is necessary to look for the possibilities of using heat pumps in cities and metropolises. The new geometry cou... [more]
Design, Multi-Perspective Computational Investigations, and Experimental Correlational Studies on Conventional and Advanced Design Profile Modified Hybrid Wells Turbines Patched with Piezoelectric Vibrational Energy Harvester Devices for Coastal Regions
Janani Thangaraj, Senthil Kumar Madasamy, Parvathy Rajendran, Safiah Zulkifli, Rajkumar Rajapandi, Hussein A. Z. AL-bonsrulah, Beena Stanislaus Arputharaj, Hari Prasath Jeyaraj, Vijayanandh Raja
January 12, 2024 (v1)
Keywords: composite materials, Computational Fluid Dynamics, FEA, forced and free vibrations, FSI, hybrid energy, hydro-energy
This work primarily investigates the performance and structural integrity of the Wells turbines for power production in coastal locations and their associated unmanned vehicles. An innovative design procedure is imposed on the design stage of the Wells turbine and thus so seven different models are generated. In the first comprehensive investigation, these seven models underwent computational hydrodynamic analysis using ANSYS Fluent 17.2 for various coastal working environments such as hydro-fluid speeds of 0.34 m/s, 1.54 m/s, 12 m/s, and 23 m/s. After this primary investigation, the best-performing Wells turbine model has been imposed as the second comprehensive computational investigation for three unique design profiles. The imposed unique design profile is capable of enhancing the hydro-power by 15.19%. Two detailed, comprehensive investigations suggest the best Wells turbine for coastal location-based applications. Since the working environments are complicated, additional advance... [more]
Multiscale CFD Simulation of Multiphase Erosion Process in a Connecting Pipe of Industrial Polycrystalline Silicon Unit
Sheng Chen, Jiarui Shi, Jun Yuan, Meng He, Yongquan Li, Liyun Zhu, Juanbo Liu, Jiangyun Wang, Guoshan Xie
January 5, 2024 (v1)
Keywords: Computational Fluid Dynamics, energy-minimization multi-scale, erosion, multiphase, polycrystalline silicon
Severe erosion phenomena often occur in industrial polycrystalline silicon units, leading to hydrogen leakage accidents and affecting long-term operation. It is favorable to use a computational fluid dynamics (CFD) simulation with the dense discrete phase model (DDPM) and the sub-grid energy-minimization multi-scale (EMMS) drag model to improve the prediction accuracy of complex multiphase erosion phenomena in a connecting pipe of an industrial polycrystalline silicon unit. Furthermore, the effect of droplet the specularity coefficient on boundary conditions is thoroughly considered. The predicted erosion behaviors are consistent with industrial data. The effects of operations parameters were discussed with three-dimensional CFD simulation, including droplet size and hydrogen volume fraction on erosion behaviors. The results indicated that the non-uniform multiphase erosion flow behavior near the wall can be simulated accurately with the EMMS drag model in a coarse mesh. A suitable dro... [more]
Modeling of Oxidative Coupling of Methane for Manufacture of Olefins—Part I: CFD Simulations
Tahyná B. Fontoura, Normando J. C. De Jesus, José Carlos Pinto
January 5, 2024 (v1)
Keywords: Computational Fluid Dynamics, fixed-bed reactors, heat and mass transfer, Olefins, oxidative coupling of methane
This paper presents a comprehensive computational fluid dynamics (CFD) model for describing the oxidative coupling of methane (OCM) carried out in fixed-bed reactors for olefin production. Initially, a single pellet model was developed and implemented to describe the heat and mass transfer within the pellet and between the gaseous and solid phases. Subsequently, sensitivity analyses were performed to assess the impact of pellet arrangement and feed conditions on the heat and mass transfer rates, subsequently affecting concentration and temperature profiles. As indicated by the simulations, a high ethylene content could be obtained with the increase in the CH4/O2 ratio, aligning well with previous experimental studies. Furthermore, it was observed that pellet arrangement can significantly affect the reactor performance. Additionally, the behavior of temperature and concentration in the gaseous and solid phases can be very different, such that pseudo-homogeneous modeling approaches shoul... [more]
Homogeneous Field Measurement and Simulation Study of Injector Nozzle Internal Flow and Near-Field Spray
Ping Chen, Rongwu Xu, Zhenming Liu, Jingbin Liu, Xusheng Zhang
November 30, 2023 (v1)
Keywords: Computational Fluid Dynamics, diesel fuel injector, internal flow, near-field spray, X-ray phase contrast imaging
The homogeneous field measurement of internal flow and spray of internal combustion engine injector nozzles under high pressure has always been one of the difficulties in experimental research. In this paper, an actual-size aluminum alloy nozzle is designed, and the simultaneous measurement of internal flow and near-field spray is successfully realized with the help of synchrotron radiation X-ray phase contrast imaging technology under an injection pressure of 30~90 MPa. For a 0.25 mm aperture nozzle, different radii of the inlet corner can induce different cavitation layer thicknesses, and the measured flow section shrinkage ratio is 0.70. The flow characteristics in the nozzle are entirely connected to the jet characteristics, indicating a tight correlation between internal flow and jet morphology. Finally, the internal cavitation of the nozzle was studied by the CFD simulation, and the simulation results are in good agreement with the experiment.
Numerical Study on High Throughput and High Solid Particle Separation in Deterministic Lateral Displacement Microarrays
Maike S. Wullenweber, Jonathan Kottmeier, Ingo Kampen, Andreas Dietzel, Arno Kwade
September 21, 2023 (v1)
Keywords: Computational Fluid Dynamics, deterministic lateral displacement, discrete element method, high throughput, immersed boundary method, particle concentration, particle separation
Deterministic lateral displacement (DLD) is a high-resolution passive microfluidic separation method for separating micron-scale particles according to their size. Optimizing these microsystems for larger throughputs and particle concentrations is of interest for industrial applications. This study evaluates the limitations of the functionality of the DLD separation principle under these specific conditions. For this reason, different particle volume fractions (up to 11%) and volumetric flow rates (corresponding to Reynolds numbers up to 50) were varied within the DLD microsystem and tested in different combinations. Resolved two-way coupled computational fluid dynamics/discrete element method (CFD-DEM) simulations including spherical particles were performed. The results show a general increase in the critical diameter with increasing volume fraction and decreasing separation efficiency. The largest tested Reynolds number (Re = 50) results in the highest separation efficiency, particu... [more]
Mixing Characteristics and Parameter Effects on the Mixing Efficiency of High-Viscosity Solid−Liquid Mixtures under High-Intensity Acoustic Vibration
Xiaobin Zhan, Lei Yu, Yalong Jiang, Qiankun Jiang, Tielin Shi
September 21, 2023 (v1)
Keywords: acoustic vibration, Computational Fluid Dynamics, high viscosity, Mixing, multiphase flow
High-intensity acoustic vibration is a new technology for solving the problem of uniform dispersion of highly viscous materials. In this study, we investigate the mixing characteristics of high-viscosity solid−liquid phases under high-intensity acoustic vibration and explore the effect of vibration parameters on the mixing efficiency. A numerical simulation model of solid−liquid−gas multiphase flow, employing the volume of fluid (VOF) and discrete phase model (DPM), was developed and subsequently validated through experimental verification. The results show that the movement and deformation of the gas−liquid surface over the entire field are critical for achieving rapid and uniform mixing of the solid−liquid phases under acoustic vibration. Increasing the amplitude or frequency of vibration can intensify the movement and deformation of the free surface of gas and liquid, improve the mixing efficiency, and shorten the mixing time. Under the condition of constant acceleration, the mixing... [more]
Effect of Al2O3, SiO2, and ZnO Nanoparticle Concentrations Mixed with EG−Water on the Heat Transfer Characteristics through a Microchannel
Ibrahim Elbadawy, Fatemah Alali, Javad Farrokhi Derakhshandeh, Ali Dinc, Mohamed Abouelela, Wael Al-Kouz
August 3, 2023 (v1)
Keywords: Computational Fluid Dynamics, heat transfer characteristics, microchannels, nanofluids
Nanofluids have gained attention for their potential to solve overheating problems in various industries. They are a mixture of a base fluid and nanoparticles dispersed on the nanoscale. The nanoparticles can be metallic, ceramic, or carbon based, depending on the desired properties. While nanofluids offer advantages, challenges such as nanoparticle agglomeration, stability, and cost effectiveness remain. Nonetheless, ongoing research aims to fully harness the potential of nanofluids in addressing overheating issues and improving thermal management in different applications. The current study is concerned with the fluid flow and heat transfer characteristics of different nanofluids using different types of nanoparticles such as Al2O3, SiO2, and ZnO mixed with different base fluids. Pure water and ethylene glycol−water (EG−H2O) mixtures at different EG−H2O ratios (ψ = 0%, 10%, 30%, 40%) are used as the base fluid. Furthermore, a rectangular microchannel heat sink is used. Mesh independe... [more]
Numerical Study of the Effects of Roughness Coupled with Inclination on a Turbulent Flow around an Obstacle
Amine Brahimi, Redha Rebhi, Mounir Alliche
August 3, 2023 (v1)
Keywords: Computational Fluid Dynamics, forced convection, friction, Nusselt numbers, obstacle, roughness
In this study, we simulate the cooling of a microprocessor by thermal convection in three different shapes: a square, a trapezoidal, and a triangular shape. The latter is improved by a variety of types of roughness, including square roughness, triangular roughness Type 1, triangular roughness Type 2, and triangular roughness Type 3. The microprocessors are kept at a constant temperature, the air flow is constant, and the geometry is fixed. The physical phenomenon is simulated by the ANSYS software. The numerical results reported in this study cover the ranges of the obstacle’s angle of inclination, 0°≤θ≤45°, (square obstacles, θ=0°, trapezoidal obstacles, 0°<θ<45°, triangular obstacles, θ=45°) and Reynolds number, 2500≤Re≤10,000. The findings relate to streamlines, dynamic pressure (max), mean velocity, temperature field, mean Nusselt number (Nu/Nu0) profiles, local coefficient of friction (Cf/f0), mean coefficient of friction (f/f0) profiles, mean velocity field with roughness,... [more]
Heat-Induced Increase in LPG Pressure: Experimental and CFD Prediction Study
Thiago Fernandes Barbosa, Domingos Xavier Viegas, MohammadReza Modarres, Miguel Almeida
August 2, 2023 (v1)
Keywords: Computational Fluid Dynamics, LPG, multiphase, pressure, risk assessment, Simulation
Computational fluid dynamics (CFD) has become a widely used tool for predicting hazardous scenarios. The present study aimed to assess CFD prediction applied to LPG containers under heating. Thus, two cylinders, each filled with propane or butane, were experimentally exposed to fire, and the pressure increment was recorded. The results were compared with those provided by a CFD method (Ansys Fluent). The limitations of the method are discussed, and a trend in the error increment and its relation to the reduced temperature increment are presented. The results obtained show that the computational method had a good agreement, with a relative error of 19% at a reduced temperature equal to 2. Furthermore, the method had a better fit with heavier alkanes, as the butane was less influenced by temperature overestimation compared with propane.
Comparative Analysis of the Performance Characteristics of Butterfly and Pinch Valves
Khalid Alkhulaifi, Ali Alharbi, Mohsen Alardhi, Jasem Alrajhi, Hamad H. Almutairi
August 2, 2023 (v1)
Keywords: butterfly valve, Computational Fluid Dynamics, numerical analysis, pinch valve, throttle valve
Valves are important components in controlling the amount of fluid going to devices. One of these types is the butterfly valve (BFV) that adjusts the amount of flow by rotating the valve disk by means of its shafts which is usually located in the middle of the flow. Despite its common usage in various applications, the BFV is known to cause a high-pressure drop. Conversely, the pinch valve is another type of flow control device that uses a pinching mechanism to open and close the inner tube by pinching at different degrees. The absence of flow-controlling mechanisms in the flow path, such as the valve disk and its shaft, contribute to the minimal pressure drop in pinch valves. The high-pressure drop in BFVs and the minimal pressure drop in pinch valve flow make it worthwhile to investigate and compare their flow at all opening positions of the two valves. Therefore, this work numerically explores the potential of using the pinch valve as an alternative to the BFV in terms of its abilit... [more]
Analysis of the Shear Stresses in a Filling Line of Parenteral Products: The Role of Fittings
Camilla Moino, Bernadette Scutellà, Marco Bellini, Erwan Bourlès, Gianluca Boccardo, Roberto Pisano
July 7, 2023 (v1)
Keywords: Computational Fluid Dynamics, filling line, fittings, parenteral products, shear stress
Fill-finish of parenteral formulations represents a crucial step in the pharmaceutical industry that necessitates careful monitoring of product stability down the line. Shear stress and interfacial stress are two elements that threaten product stability, the respective contributions of which are still up for debate. This article focuses on the analysis of shear stress in the sampling phase of the filling line. Specifically, Computational Fluid Dynamics (CFD) simulations were employed to determine the shear stress distribution experienced by a protein-based parenteral drug as it passes through sampling fittings of various shapes under laminar and turbulent regime conditions. Rather than seeking the specific mechanism triggering the destabilization of a product, an attempt was made to analyze the fluid dynamics within these fittings and offer further understanding of the resulting shear stress. In addition, information was collected on the product path within the fittings, which allowed... [more]
Mathematical Modelling and CFD Simulation for Oxygen Removal in a Multi-Function Gas-Liquid Contactor
Mengdie Wang, Qianqian Nie, Guangyuan Xie, Zhongchao Tan, Hesheng Yu
July 7, 2023 (v1)
Keywords: Computational Fluid Dynamics, degassing, gas-liquid contactor, mass transfer, reactor modelling
This paper presents and compares the mathematical models and computational fluid dynamics (CFD) models for degassing of oxygen from water in a laboratory-scale multi-function gas-liquid contactor under various operating conditions. The optimum correlations of the overall volumetric liquid-phase mass transfer coefficient (kLa) are determined by the mathematical models of specific contactors. Both the continuous-reactor model and semi-batch model can evaluate the degassing efficiency with relative errors within ±13%. Similarly, CFD models agree with experimental data with relative errors of ±10% or less. Overall, the mathematical models are deemed easy to use in engineering practice to assist the selection of efficient contactors and determine their optimum operation parameters. The CFD models have a wider applicability, and directly provide the local mass transfer details, making it appropriate for harsh industrial scenarios where empirical correlations for important quantities are unav... [more]
Research on Wake Field Characteristics and Support Structure Interference of Horizontal Axis Tidal Stream Turbine
Jiayan Zhou, Huijuan Guo, Yuan Zheng, Zhi Zhang, Cong Yuan, Bin Liu
May 24, 2023 (v1)
Keywords: Computational Fluid Dynamics, horizontal axis tidal stream turbine, support structure, turbine power coefficient, wake flow
The harnessing and utilization of tidal current energy have emerged as prominent topics in scientific inquiry, due to their vast untapped resource potential, leading to numerous investigations into the efficacy of hydrokinetic turbines under various operational conditions. This paper delineates the wake field characteristics and performance of horizontal axis tidal stream turbines under the influence of support structures, using a comprehensively blade-resolved computational fluid dynamics (CFDs) model that employs Reynolds-averaged Navier−Stokes (RANS) equations in combination with the RNG k-ε turbulence model. To achieve this, the study utilized experimental tank tests and numerical simulations to investigate the distribution characteristics and recuperative principles of the turbine’s wake field. The velocity distribution and energy augmentation coefficient of the wake field showed strong agreement with the experimental results. To further assess the effect of support structures on... [more]
CFD Investigation of a Hybrid Wells Turbine with Passive Flow Control
Mohammad Nasim Uddin, Michael Atkinson, Frimpong Opoku
May 23, 2023 (v1)
Keywords: blade stall, Computational Fluid Dynamics, Gurney flap, RANS, turbulence, Wave Energy, Wells turbine
In the past decade, there has been renewed interest in wave energy harvesting utilizing oscillating water columns (OWC), one of the most well-studied wave energy harnessing technologies. In the OWC, pneumatic power from ocean waves is converted to mechanical energy by Wells turbines. It should be noted, however, that such turbines tend to perform poorly, have a limited operating range, and have low efficiency. In the present study, we incorporate a rectangular Gurney flap (GF) at the trailing edge (TE) of a Wells turbine consisting of hybrid airfoil (NACA 0015 and NACA 0025) blades with variable chord distribution along the span. This passive flow control mechanism was adopted to achieve increased power production by the Wells turbine. This study aimed to determine the aerodynamic performance of the variable chord turbine with GF compared to a turbine with a constant chord. By using ANSYS™ CFX, the three-dimensional, steady-state, incompressible Reynolds averaged Navier−Stokes (RANS) e... [more]
CFD Analysis of the Forced Airflow and Temperature Distribution in the Air-Conditioned Operator’s Cabin of the Stationary Rock Breaker in Underground Mine under Increasing Heat Flux
Adam Wróblewski, Arkadiusz Macek, Aleksandra Banasiewicz, Sebastian Gola, Maciej Zawiślak, Anna Janicka
May 23, 2023 (v1)
Keywords: cabin air conditioning analysis, cabin interior, Computational Fluid Dynamics, heat transfer, thermal hazard
The exploitation of natural resources is associated with many natural hazards. Currently, the copper ore deposits exploited in Polish mines are located at a depth of about 1200 m below the surface. The primary temperature of the rocks in the exploited areas reaches 48 ∘C, which constitutes a major source of heat flux to the mine air. However, another important source of heat is the machine plant, which mainly consists of machines powered by diesel engines. Following the results of in situ measurements, boundary conditions for a simulation were determined and a geometric model of the cabin was created. Furthermore, an average human model was created, whose radiative heat transfer was included in the analysis. Three cases were studied: the first covering the current state of thermal conditions, based on the measurement results, and two cases of forecast conditions. In the second case, the temperature of the conditioned air was determined, and in the third, the flow velocity required to e... [more]
Variable-Speed Propeller Turbine for Small Hydropower Applications
Eva Bílková, Jiří Souček, Martin Kantor, Roman Kubíček, Petr Nowak
May 23, 2023 (v1)
Keywords: axial propeller turbine, CAESES, Computational Fluid Dynamics, Optimization, tailor-made design, variable-speed
Standard technical solutions are not cost-effective for many small hydropower sites. This study aims to demonstrate the workflow for the tailor-made variable-speed axial propeller turbine and provide proof of this concept. The turbine is designed to meet the site’s specific space limitations and operating range needs. The runner shape is adjusted to the variable-speed operation and defined hydraulic profile using a parametric geometry model and CFD-based optimization. The variable-speed propeller turbine shows excellent flow control while keeping the mechanical design simple. The tailor-made approach minimizes construction costs using existing structures and is highly suitable for mini-hydropower applications. The prototype—an atypical turbine designed for highly restricted space and installed on-site—serves as proof of the concept. The findings on the design of axial variable-speed turbines are presented.
Numerical Simulation of Nonlinear Processes in the “Thruster—Downhole Motor—Bit” System While Extended Reach Well Drilling
Andrey A. Kunshin, George V. Buslaev, Matthias Reich, Dmitriy S. Ulyanov, Dmitriy I. Sidorkin
May 23, 2023 (v1)
Keywords: Computational Fluid Dynamics, downhole hydraulic thrusting device, drilling efficiency, ERD wells, PDC bits, vibration reduction, weight on the bit
The relevance of the application of hydraulic thruster technology is determined by the technological limitations of drilling both vertical and horizontal wells. The existing experimental studies confirm the effectiveness of the technology, but its widespread implementation is hindered by the lack of scientific foundations for its operation in combination with a downhole motor and bit. Our research methodology includes methods for analyzing scientific and technical information as well as methods of numerical modeling using programming languages and ready-made software packages for CFD calculations. Verification of the simulation results was carried out on the basis of the experimental field studies previously conducted with the participation of the authors of the article. This article presents the results of the analysis of the current state of the problem and computer physical and mathematical modeling of the work of the thruster together with the bit and downhole motor when drilling a... [more]
Power Output Optimisation via Arranging Gas Flow Channels for Low-Temperature Polymer Electrolyte Membrane Fuel Cell (PEMFC) for Hydrogen-Powered Vehicles
James Chilver-Stainer, Anas F. A. Elbarghthi, Chuang Wen, Mi Tian
May 23, 2023 (v1)
Keywords: Computational Fluid Dynamics, fuel cell, gas flow channel, Hydrogen, hydrogen-powered vehicle, micro porous layer, optimal configuration, polymer electrolyte membrane, power output
As we move away from internal combustion engines to tackle climate change, the importance of hydrogen-powered vehicles and polymer electrolyte membrane fuel cell (PEMFC) technology has dramatically increased. In the present study, we aimed to determine the optimal configuration for the power output of a PEMFC system using computational fluid dynamics (CFD) modelling to analyse variations of the primary serpentine design of gas flow channels. This helps improve efficiency and save on valuable materials used, reducing potential carbon emissions from the production of hydrogen vehicles. Different numbers of serpentine gas channels were represented with various spacing between them, within the defined CFD model, to optimise the gas channel geometry. The results show that the optimum configuration was found to have 11 serpentine channels with a spacing of 3.25 mm. In this optimum configuration, the ratio between the channel width, channel spacing, and serpentine channel length was found to... [more]
Heat Transfer Coefficient Distribution—A Review of Calculation Methods
Piotr Duda
May 23, 2023 (v1)
Keywords: Computational Fluid Dynamics, heat and mass transfer analogy, inverse heat conduction, local HTC, temperature measurement
Determination of the heat transfer coefficient (HTC) distribution is important during the design and operation of many devices in microelectronics, construction, the car industry, drilling, the power industry and research on nuclear fusion. The first part of the manuscript shows works describing how a change in the coefficient affects the operation of devices. Next, various methods of determining the coefficient are presented. The most common method to determine the HTC is the use of Newton’s law of cooling. If this method cannot be applied directly, there are other methods that can be found in the open literature. They use analytical formulations, the lumped thermal capacity assumption, the 1D unsteady heat conduction equation for a semi-infinite wall, the fin model, energy conservation and the analogy between heat and mass transfer. The HTC distribution can also be calculated by means of computational fluid dynamics (CFD) modelling if all boundary conditions with fluid and solid prop... [more]
3D Transient CFD Simulation of an In-Vessel Loss-of-Coolant Accident in the EU DEMO WCLL Breeding Blanket
Mauro Sprò, Antonio Froio, Andrea Zappatore
May 23, 2023 (v1)
Keywords: Computational Fluid Dynamics, EU DEMO, LOCA, nuclear fusion, two-phase flow, WCLL
The in-vessel Loss-of-Coolant Accident (LOCA) is one of the design basis accidents in the design of the EU DEMO tokamak fusion reactor. System-level codes are typically employed to analyse the evolution of these transients. However, being based on a lumped approach, they are unable to quantify localised quantities of interest, such as local pressure peaks on the vacuum vessel walls, to which the failure criteria are linked. To calculate local quantities, the 3D nature of the phenomenon needs to be considered. In this work, a 3D transient model of the in-vessel LOCA from a water-cooled blanket is developed. The model is implemented in the commercial CFD software STAR-CCM+. It simulates the propagation of the water jet in the vessel from the beginning of the accident, thus accounting for the phase change of the water, i.e., from the pressurised liquid phase to the vapour phase inside the vessel, being the latter at a much lower pressure than in the blanket coolant pipes. Due to the large... [more]
CFD Evaluation of Thermal Conditioning in a House of Social Interest with a Solar Chimney Arrangement in Guanajuato, Mexico
Sergio Rodriguez Miranda, G. O. Gamboa, Marco Antonio Zamora-Antuñano, Neín Farrera-Vázquez, Raúl García-García
April 28, 2023 (v1)
Keywords: Computational Fluid Dynamics, Simulation, solar chimney, thermal comfort
The aim of using electromechanical air conditioning in buildings is to maintain thermal comfort for its occupants; however, this type of air conditioning represents 40% of the total energy consumption of a building, generating economic and environmental impacts, because fossil fuels are the main source of energy. To reduce the use of electromechanical conditioning, it is possible to take advantage of the climatic conditions of the region to improve its performance. Due to the small number of works that quantitatively support measures aimed at improving the thermal behavior of houses in an integral way and the growth of mass construction in Mexico, in the present work, a solar chimney is incorporated in a typical type of social interest housing in Guanajuato. The incorporation of the solar chimney was simulated by using computational fluid dynamics (CFD) using ANSYS and evaluated by ASHRAE Standard 55-2017. The selected arrangement induces air flow inside without the need for external f... [more]
Influence of Impeller and Mixing Tank Shapes on the Solid−Liquid Mixing Characteristics of Vanadium-Bearing Shale Based on the DEM-VOF Method
Yue Hu, Yimin Zhang, Nannan Xue, Qiushi Zheng
April 28, 2023 (v1)
Keywords: Computational Fluid Dynamics, DEM-VOF coupling method, mixing tank, vanadium shale
The mixing tank is important equipment for industrial applications in the wet vanadium extraction process, but in practice, there are problems, such as uneven mixing of minerals. In this study, the effect of different types of impellers and different mixing tank structures on the suspended mass of particles was simulated using the discrete element method and volume of fluid method (DEM-VOF). The simulation results show that the round-bottomed tank performed mixing better than the flat-bottomed tank at different particle densities, and the flat-bottomed tank was prone to particle stratification and other phenomena. The round-bottomed mixing tank could better improve the solid−liquid suspension effect. In this study, the coefficient of variation σ was introduced to characterize the suspended mass of particles. By monitoring the σ value, it was found that the blade pitch angle 45 (BPA45) had the best mixing uniformity in the inclined pitched blade turbine (PBT). As the PBT impeller pitch... [more]
Wind Turbine Blade-Tip Optimization: A Systemic Computational Approach
Panagiotis Zouboulis, Elias P. Koumoulos, Anna Karatza
April 28, 2023 (v1)
Keywords: 3D printing, additive manufacturing, blade tip, bladelet, Computational Fluid Dynamics, Optimization, topology, wind energy
Curved bladelets on wind turbine blades play an important role in improving the performance and efficiency of wind turbines. Implementing such features on the tip of wind turbine blades can improve their overall aerodynamic characteristics by reducing turbulence and loading without hindering lift generation and overall efficiency, thus leading to increased energy capture and reduced costs over the life of the turbine. Subjecting the integrated blade tip to optimization procedures can maximize its beneficial contribution to the assembly in general. Within this context, a systemic workflow is proposed for the optimization of a curved bladelet implemented on a wind turbine blade. The approach receives input in the form of an initial tip geometry and performs improvements in two distinct stages. Firstly, shape optimization is performed directly on the outer shape to enhance its aerodynamic properties. Subsequently, the topology of its interior structure is refined to decrease its mass whil... [more]
Study and Validation of a Novel Grouting Clamp Type Deepwater Oilfield Pipeline Repair Method Based on Computational Fluid Dynamics
Yuliang Lu, Dongtao Liu, Xinjie Wei, Qiaogang Xiao, Jiming Song, Yajun Yu
April 28, 2023 (v1)
Keywords: Computational Fluid Dynamics, deepwater field, numerical simulation, pipeline repair, plugging agent
In order to handle the corrosion of underwater production pipe sinks in deepwater oil fields, a non-solid phase silicone plugging agent, an external clamp, and an underwater injection tool are combined in this paper’s innovative pipeline repair technique proposal. The optimal main agent to curing the agent ratio for non-solid phase silicone plugging agents was found to be 100:25, which was achieved through an experimental examination of the curing process. The compressive and cementing strength changes in the curd plugging agent were disclosed by testing and evaluating the mechanical behavior of the plugging agent. In addition, the limits of the compressive and cementing strength were found to be 143 MPa and 11.6 MPa, respectively. Based on this, a computational-fluid-dynamics(CFD)-based analytical approach of the complicated flow field in a deep sea environment on the eroding impact of a plugging agent was developed. Through numerical simulation testing, the mathematical relationship... [more]
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