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total: 82
Search results for: CFD, DEM, FLUID FLOW, FRACTURE, HYDRO-FRACKING, MESO-SCALE, ROCK
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Optimization of hydrodynamic vortex separator for removal of sand particles from storm water by computational fluid dynamics
PublicationStorm water treatment has been gradually acknowledged for the removal of pollutants from urban areas using the hydro cyclone separation technique. The separation efficiency of the hydrodynamic vortex separator (HDVS) is a complex phenomenon. With the aim enhance the separation potency of HDVS for storm runoff to get rid of sand particles, the HDVS with different structural configurations was studied by computational fluid dynamics....
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A new open-source software developed for numerical simulations usingdiscrete modeling methods
PublicationThe purpose of this work is to present the development of an open-source software based on a discrete description of matter applied to study the behavior of geomaterials. This software uses Object Oriented Programming techniques, and its methodology design uses three different methods, which are the Discrete Element Method (DEM) [F. Donzé, S.A. Magnier, Formulation of a three-dimensional numerical model of brittle behavior, Geophys....
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Pin Angle Thermal Effects on Friction Stir Welding of AA5058 Aluminum Alloy: CFD Simulation and Experimental Validation
PublicationThe friction stir welding (FSW) of tool pin geometry plays a critical role in the final properties of the produced joint. The tool pin geometry directly affects the generation of heat and the flow of internal materials during the FSW process. The effects of the FSW tool pin angle on heat generation and internal flow have not been quantitatively investigated in detail. In this manuscript, a validated Computational Fluid Dynamic...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublicationThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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Scale effect in the self-propulsion prediction for Ultra Large Container Ship with contra-rotating propellers
PublicationThis article addresses the problem of the scale effect for an Ultra Large Container Ship (ULCS) with a novel twin-crp-pod propulsion system. Twin-crp-pod steering-propulsion arrangement is an innovative solution that gains from three well-known systems: twin-propeller, contra-rotating propellers and pod propulsors. It is expected that applying the twin-crp-pod system to the analysed Ultra Large Container Ship will increase propulsion...
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Design Equation for Stirring Fluid by a Stream Pump in a Circulating Tank
PublicationA circulating tank is a very useful theoretical scheme for many fluid-flow objects in several branches of engineering. The motion of the fluid in such objects can be induced in different ways. A stream pump provides an especially interesting possibility; however, the quantitative description of such devices shows some shortcomings. Such a device is analogous to a jet pump, thus has similar advantages (simplicity of construction,...
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Effects of Noncontact Shoulder Tool Velocities on Friction Stir Joining of Polyamide 6 (PA6)
PublicationIn this study, the effects of the traverse and rotational velocities of the noncontact shoulder tool on the heat generation and heated flux during the friction stir joining of high-density polyamide 6 (PA6) polymer were investigated. The computational fluid dynamics (CFD) method was employed to simulate the thermomechanical phenomena during the friction stir joining (FSJ) process of PA6. A developed model was used to consider the...
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On the internal efficiency of a turbine stage: classical and CFD definitions
PublicationAlmost entire fleet of steam turbines in Poland was designed between 1950 – 1980 with the use of the so-called zero dimensional (0D) calculation tools. For several years, design and modernization of the turbines occur in assistance with the state of the art methods that describe working fluid flow field based on 3D models and CFD codes. This cooperation between 0D and 3D codes requires exchange of overall, integral information...
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HYDROGEN PRODUCTION PERFORMANCE IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF NI3AL
PublicationThe main aim of the following paper is mathematical modelling for momentum, heat and mass transfer, which is accompanied by chemical surface reactions of the flow of the mixture helium and methanol. The thermocatalytic devices used for decomposition of hydrocarbons incorporate vertical microchannels coupling at the ends and heated to 500 oC at the walls. The results of the experiment were compared with CFD calculations to calibrate...
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PROPELLER INVESTIGATIONS BY MEANS OF NUMERICAL SIMULATION
PublicationThe analyses of hydroacoustics are of high interest at the moment due to strong impact of hydroacoustic phenomena on marine environment; the noises, generated e.g. by marine traffic, may be harmful for sea life. The analyses presented here are focused on one of main sources of noises generated by ships, i.e. cavitating propeller. The goal of the work is the assessment of the cavitation phenomenon, carried out with the standard...
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DETERMINATION OF THE AERODYNAMIC DRAG OF PNEUMATIC LIFE RAFTS AS A FACTOR FOR INCREASING THE RELIABILITY OF RESCUE OPERATIONS
PublicationEnsuring the safety of ship crews at sea is of the utmost importance. Life rafts are one of the basic components of any seagoing vessel and ensuring their stability is an important component of maritime research. This study concerns the determination of the aerodynamic drag coefficients of pneumatic life rafts in a full range of wind speed and directions. The drag coefficients are based on full-scale experimental studies and numerical...
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Experimental study on the selected aspects of bow thruster generated flow field at ship zero-speed conditions
PublicationThe paper presents the results of experimental study on the interaction between the bow thrusters understood as the flow field changes generated by bow tunnel thruster in deep water conditions operated as a single and twin units. The research was limited to zero-speed case for the ship dead in the water. The influence of the hull form and jet spread between the neighbouring thrusters for several combinations of the applied bow...
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CFD COUPLING OF VOF MODEL WITH ARRHENIUS EQUATION FOR ANALYSIS OF LASER-INDUCED THERMAL DEACTIVATION OF E. COLI
PublicationUnderstanding bacterial deactivation at the micro-scale, particularly with E. coli, is crucial for advancing microbiology and has promising applications in biomedical research. In this research contribution, we investigate the thermal inactivation of E. coli bacteria using gold nanoparticles irradiated by a green 1-W laser within a microfluidic chamber. The microfluidic device comprises a fluidic chamber filled with a thin film...
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Example of Using Particle Swarm Optimization Algorithm with Nelder–Mead Method for Flow Improvement in Axial Last Stage of Gas–Steam Turbine
PublicationThis article focuses principally on the comparison baseline and the optimized flow efficiency of the final stage of an axial turbine operating on a gas–steam mixture by applying a hybrid Nelder– Mead and the particle swarm optimization method. Optimization algorithms are combined with CFD calculations to determine the flowpaths and thermodynamic parameters. The working fluid in this study is a mixture of steam and gas produced...
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Mathematical modeling of hydrogen production performance in thermocatalytic reactor based on the intermetallic phase of Ni3Al
PublicationThe main goal of the following work is to adjust mathematical modelling for mass transfer, to specific conditions resulting from presence of chemical surface reactions in the flow of the mixture consisting of helium and methanol. The thermocatalytic devices used for decomposition of organic compounds incorporate microchannels coupled at the ends and heated to 500 oC at the walls regions. The results of the experiment were compared...
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Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method
PublicationPurpose The goal of this study was to develop a complete workflow allowing for conducting computational fluid dynam- ics (CFD) simulation of airflow through the upper airways based on computed tomography (CT) and cone-beam computed tomography (CBCT) studies of individual adult patients. Methods This study is based on CT images of 16 patients. Image processing and model generation of the human nasal cavity and paranasal sinuses...
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Modeling of entrained flow steam gasification of sewage sludge
PublicationProper management of sewage sludge becomes increasingly problematic due to legal requirements aiming at diminishing environmental impact, as well as rationalizing the utilization from the point of view of logistics. Steam gasification of sewage sludge can result in very good quality of the producer gas. So far, the works have been focused on the gasification in fixed bed gasifiers. However, this does not allow to take full advantage...
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Deformable model of a butterfly in motion on the example of Attacus atlas
PublicationInsect wings can undergo significant chordwise (camber) as well as spanwise (twist) deformation during flapping flight but the effect of these deformations is not well understood. The shape and size of butterfly wings leads to particularly large wing deformations, making them an ideal test case for investigation of these effects. High-speed videogrammetry was used to capture the wing kinematics and deformations. The movements of...
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Investigation of the thermal effects in water-lubricated journal bearings with axial grooves
PublicationWater-lubricated hydrodynamic journal bearings are frequently applied as stern tube bearings due to their advantages over other bearing types. They are environmentally friendly, can operate without sealings and in conditions of low friction losses. The most popular are bearings with open axial grooves, which require, for proper operation, forced axial flow of the lubricating water. Correctly designed and operated stern tube bearings...
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Experimental and numerical investigation of mercury removal from flue gas by sorbent polymer composite
PublicationThis paper presents an experimental and numerical investigation of the performance of a sorbent polymer composite (SPC) material used for removing mercury from the flue gases in a full-scale industrial installation. The investigated material is an attractive alternative to activated carbon, which is commonly used for this purpose. While the application of the SPC is characterized by high capital expenditures, this technology offers...
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Natural radioactivity of solid and liquid phases from shale oil and gas prospection in Pomerania
PublicationIonizing radiation intensity data and estimation of equivalent absorbed dose from solid and liquid samples from prospection of shale gas and oil at selected sites in Pomerania are presented. Naturally occurring radioactive materials (NORM) are associated with geological formations or fluids and can be enhanced during oil and gas production. They appear in e.g. drilling cuttings, flow back water, produced water, scale and sludge....
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Spatial aspects of urban air quality management: Estimating the impact of micro-scale urban form on pollution dispersion
PublicationUrban planning and design solutions affect urban ventilation conditions, thus mitigating the effects of atmospheric pollution. However, these findings are not being implemented in the planning practice to a sufficient extent, partly due to the lack of specific guidelines. Moreover, many urban air quality monitoring (AQM) sites have low represnentativeness and thus do not provide comprehensive data for effective urban air pollution control...
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Effect of Pin Shape on Thermal History of Aluminum-Steel Friction Stir Welded Joint: Computational Fluid Dynamic Modeling and Validation
PublicationThis article studied the effects of pin angle on heat generation and temperature distribution during friction stir welding (FSW) of AA1100 aluminum alloy and St-14 low carbon steel. A validated computational fluid dynamics (CFD) model was implemented to simulate the FSW process. Scanning electron microscopy (SEM) was employed in order to investigate internal materials’ flow. Simulation results revealed that the mechanical work...
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Constrained aerodynamic shape optimization using neural networks and sequential sampling
PublicationAerodynamic shape optimization (ASO) involves computational fluid dynamics (CFD)-based search for an optimal aerodynamic shape such as airfoils and wings. Gradient-based optimization (GBO) with adjoints can be used efficiently to solve ASO problems with many design variables, but problems with many constraints can still be challenging. The recently created efficient global optimization algorithm with neural network (NN)-based prediction...
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The retrofitting of ships by applying retractable bow hydrofoils: a case study
PublicationIncreasing environmental requirements and a relatively long ship life of 30 years mean more attention is needed to retrofit existing ships. One possibility is using hydrofoils to reduce the ship’s resistance and improve comfort and safety in rough sea conditions. This study investigates the influence of retractable bow hydrofoils on the seakeeping performance and operational conditions of a selected case study vessel (V-shaped...
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Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography–Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase
PublicationThis study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO2) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO2 without addition of cosolvent in ultrahigh performance supercritical fluid chromatography–mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono-...
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Effect of annealing temperature on slurry erosion resistance of ferritic X10CrAlSi18 steel
PublicationIn the present work, the slurry erosion tests were carried out to investigate the influence of heat treatment on slurry erosion process of ferritic X10CrAlSi18 stainless steel using a slurry pot test rig. X10CrAlSi18 stainless steel was tested in as-received condition and after annealing at three different temperatures: 600°C, 800°C and 1000°C. Degradation of materials due to slurry erosion depends on many factors connected with...
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The use of constructed wetlands for the treatment of industrial wastewater
PublicationConstructed wetlands are characterized by specific conditions enabling simultaneous various physical and biochemical processes. This is the result of specific environment for the growth of microorganisms and hydro-phytes (aquatic and semiaquatic plants) which are capable of living in aerobic, anaerobic and facultative anaerobic conditions. Their interaction contributes to the intensification of oxidation and reduction responsible...
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The protocol for using elastic wall model in modeling blood flow within human artery
PublicationMedical diagnostic tools will play a major role in the future for an effective patient treatment and reduction their mortality, related to the cardiovascular system diseases (CVDs). There is an urgent need for developing diagnostic procedure to be robust, reliable, accurate and efficient, in the framework of a paradigm shift. Application of numerical techniques is seen as a perspective tool for such purpose. Nevertheless, existing...
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Review of Selected Methods for Prediction of Added Resistance in Following Waves
PublicationThe added resistance in waves is a mean value of non-linear, second order reaction of a ship to incoming waves. In the beginning of the 20th century, the experimental methods for investigation of ship hydrodynamics at model scale were developed. They allowed the evaluation of added resistance by measurements in irregular waves (directly) or by measurements in regular waves (in-direct method). The main goal was to find more precise...
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Multi-objective optimization of the cavitation generation unit structure of an advanced rotational hydrodynamic cavitation reactor
PublicationHydrodynamic cavitation (HC) has been widely considered a promising technique for industrial-scale process intensifications. The effectiveness of HC is determined by the performance of hydrodynamic cavitation reactors (HCRs). The advanced rotational HCRs (ARHCRs) proposed recently have shown superior performance in various applications, while the research on the structural optimization is still absent. The present study, for the...
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On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings
PublicationJournal Menu About this Journal Abstracting and Indexing Aims and Scope Article Processing Charges Articles in Press Author Guidelines Bibliographic Information Citations to this Journal Contact Information Editorial Board Editorial Workflow Free eTOC Alerts Publication Ethics Submit a Manuscript Table of Contents Abstract Full-Text PDF Full-Text HTML...