Search
Filters
total: 3537
-
Catalog
displaying 1000 best results Help
Search results for: fluid-solid interaction
-
Numerical investigation of multiphase blood flow coupled with lumped parameter model of outflow
PublicationPurpose The purpose of this paper is the application of the computational fluid dynamics model simulating the blood flow within the aorta of an eight-year-old patient with Coarctation of Aorta. Design/methodology/approach The numerical model, based on commercial code ANSYS Fluent, was built using the multifluid Euler–Euler approach with the interaction between the phases described by the kinetic theory of granular flow (KTGF). Findings A...
-
Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results
PublicationThe edge criteria for magnetic-fluid seals durability research are critical for the seal'stechnological usefulness. The magnetic fluid seal technology in water is much moredifficult technological problem in comparison to gas or vacuum environment. There isalways problem with immediate contact between magnetic fluid and the environmentaluninspected liquids. In the paper are presented ways of experiments definitions carried outwith...
-
Influence of Properties of Hydraulic Fluid on Pressure Peaks in Axial Piston Pumps’ Chambers
PublicationThe article concentrates on the research of the pressure peaks in a working chamber of an axial piston pump. The main focus of the article is the influence of fluid properties on the pressure peaks value. Experimental and analytical methods were used to determine the impact of the fluid density, viscosity, compressibility and aeration. The article describes the pressure peak generation process and explains the theoretical basis...
-
Performance Evaluation of Asphalt Binder Modified with Shear Thickening Fluid
PublicationThis paper aims at using a dilatant or shear thickening fluid (STF) [a non-Newtonian fluid consisting of particles of nano-silica suspended in a liquid medium, i.e., ethylene glycol (EG), which acts as a carrier fluid; proportion 40:60] as additive or modifier of bitumen in order to enhance its viscoelastic properties. A commonly-used performance grading (PG) system, storage stability test, and different conventional and rheological...
-
Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
-
Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
-
Vortex flow caused by periodic and aperiodic sound in a relaxing maxwell fluid
PublicationThis paper concerns the description of vortex flow generated by periodic and aperiodic sound in relaxing Maxwell fluid. The analysis is based on governing equation of vorticity mode, which is a result of decomposition of the hydrodynamic equations for fluid flow with relaxation and thermal conductivity into acoustical and non-acoustical parts. The equation governing vorticity mode uses only instantaneous, not averaged over sound...
-
Thermal analysis of Magnetohydrodynamics (MHD) Casson fluid with suspended Iron (II, III) oxide-aluminum oxide-titanium dioxide ternary-hybrid nanostructures
PublicationThis study is carried out to enhance and analyze the thermal performance of non-Newtonian Casson fluid by immersing Ternary hybrid nanoparticles Fe3O4-Al2O3-TiO2 uniformly. To model the behaviour of such complex phenomena mathematically, a system of complex transport differential equations is developed by utilizing a non-Fourier heat transfer model for energy transport. The non-dimensional system of transport equations involving...
-
Life tests of a rotary single-stage magnetic-fluid seal for shipbuilding applications
PublicationUse of the magnetic fluid seal technology in water is much more difficult technological problem in comparisonto gas or vacuum environment. Some seals constructed up to time been are designed as hybrid, two stagesealing structures with shields or mechanical seals used as protection measures to the magnetic fluid seal.Anyway, there is always problem with immediate contact between magnetic fluid and the environmentalliquid. In the...
-
generation of the vorticity mode by sound in a bingham plastic
PublicationThis study investigates interaction between acoustic and non-acoustic modes, such as vorticity mode,in some class of a non-newtonian fluid called Bingham plastic. The instantaneous equations describinginteraction between different modes are derived. The attention is paid to the nonlinear effects in the fieldof intense sound. The resulting equations which describe dynamics of both sound and the vorticity modeapply to both periodic...
-
Thermal self-action effects for acoustic beams containing fronts in a Maxwell relaxing fluid
PublicationThis paper examines the thermal self-action of acoustic beams in a Maxwell relaxing fluid. This type of thermal self-action differs from that in a Newtonian fluid and behaves differently depending on a ratio of sound period and time of thermodynamic relaxation. The self-action which relates to sound beams containing shock fronts is also discussed. In addition, stationary and non-stationary types of self-action are considered.
-
Piotr Jasiński prof. dr hab. inż.
PeoplePiotr Jasinski obtained MSc in electronics in 1992 from the Gdansk University of Technology (GUT), Poland. Working at GUT, he received PhD in 2000 and DSc in 2009. Between 2001 and 2004 Post Doctoral Fellow at Missouri University of Science and Technology, while between 2008 and 2010 an Assistant Research Professor. Currently is an Associate Professor at Gdansk University of Technology working in the field of electronics, biomedical...
-
FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS
PublicationThe article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions....
-
Effect of the Cavitation Generation Unit Structure on the Performance of an Advanced Hydrodynamic Cavitation Reactor for Process Intensifications
PublicationThe advanced rotational hydrodynamic cavitation reactors (ARHCRs) that appeared recently have shown obvious advantages compared with conventional devices in process intensifications. In ARHCRs, the cavitation generation unit (CGU) located on the rotor and stator basically determines their performance. For the first time, the present study investigated the effect of the CGU structure on the performance of a representative ARHCR...
-
Multi-stage magnetic-fluid seals for operating in water - life test procedure, test stand and research results. Part II Results of life tests of multi-stage magnetic - fluid seal operating in water
PublicationThe edge criteria for magnetic-fluid seals durability research were described in previous article [24] and now the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are:...
-
Insights Into Hydrodynamics of Spinning Fluids Reactor
PublicationSpinning fluids reactor (SFR) is one of the most efficient gas-liquid contacting system with high potential of application in many fields. The unique solution of SFR is the contacting of two spinning fluids which generated centrifugal force. The aim of this study was to investigate the pressure field distribution on the inner surface of reactors dispersing element. Obtained results confirm the high heterogeneity of the field pressure...
-
The Magnetic Fluid Seals Research Results vs. Kelvin-Helmholtz (K-H) instability and Preliminary Conclusions
PublicationIn the article a magnetic-fluid seals durability research and the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are: critical pressure, critical motion velocity and...
-
Effect of Laminar Pulsatile Fluid Flow on Separation of Volatile Organic Compounds from Aqueous Solution by a Hollow Fiber Membrane-Based Process
PublicationIn this study, a laminar pulsatile fluid flow was used for the separation of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) from aqueous solutions. Polyether sulfone hollow fiber membrane has been applied to this process. The effects of BTEX concentration, and feed and extraction flow rates were examined. It was found that the application of the pulsatile fluid flow with...
-
Effect of applied standard wood machining fluid on colour and chemical composition of the machined wood surface
PublicationAppropriate monitoring of wood machining processes is a key issue to ensure the expected quality of the processed wood, expected efficiency and minimize energy consumption of production processes. A new trend is the design of environmentally friendly machining fluids. In this paper, as a preliminary study in this field, the effect of applied standard wood machining fluid on changes in the colour and chemical composition of the...
-
A pore-scale thermo–hydro-mechanical model for particulate systems
PublicationA pore scale numerical method dedicated to the simulation of heat transfer and associated thermo–hydro-mechanical couplings in granular media is described. The proposed thermo–hydro-mechanical approach builds on an existing hydromechanical model that employs the discrete element method for simulating the mechanical behavior of dense sphere packings and combines it with the finite volume method for simulating pore space fluid flow...
-
Acoustic heating produced in the boundary layer
Publication: Instantaneous acoustic heating of a viscous fluid flow in a boundary layer is the subject of investigation. The governing equation of acoustic heating is derived by means of a special linear combination of conservation equations in the differential form, which reduces all acoustic terms in the linear part of the final equation but preserves terms belonging to the thermal mode. The procedure of decomposition is valid in a weakly...
-
Modelling hydraulic and capillary-driven two-phase fluid flow in unsaturated concretes at the meso-scale with a unique coupled DEM-CFD technique
PublicationThe goal of the research was to demonstrate the impact of thin porous interfacial transition zones (ITZs) between aggregates and cement matrix on fluid flow in unsaturated concrete caused by hydraulic/capillary pressure. To demonstrate this impact, a novel coupled approach to simulate the two-phase (water and moist air) flow of hydraulically and capillary-driven fluid in unsaturated concrete was developed. By merging the discrete...
-
Time fractional analysis of Casson fluid with application of novel hybrid fractional derivative operator
PublicationA new approach is used to investigate the analytical solutions of the mathematical fractional Casson fluid model that is described by the Constant Proportional Caputo fractional operator having non-local and singular kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, and the governing equations were then transformed in non-dimensional form. For the sake of generalized...
-
Pharmaceutical and forensic drug applications of chiral supercritical fluid chromatography
PublicationTHE SUPERCRITICAL FLUID IS AN EXCELLENT CHOICE AS THE CHROMATOGRAPHIC MOBILE PHASE BECAUSE IT ALLOWS RAPID SEPARATION WITH HIGH EFFICIENCY AND APPLICATIONS INVOLVING ENANTIORESOLUTION ARE COMMON. SUPERCRITICAL FLUID CHROMATOGRAPHY (SFC) IS INCREASINGLY USED FOR ANALYTICAL, SEMI-PREPARATIVE AND PREPARATIVE PURIFICATION OF CHIRAL COMPOUNDS, INCLUDING PRODUCTION OF ENANTIOMERS THAT ARE MAINLY ENCOUNTERED DURING DRUG DEVELOPMENT. SFC...
-
EXPERIMENTAL STUDY OF SURFACE ROUGHNESS EFFECT ONTHE RHEOLOGICAL BEHAVIOR OF MR FLUID
PublicationPaper presents the results of shear stress measurements of a commercial magnetorheological fluid using a plate-plate type geometry with a modified working surface. The purpose of the study was to determine the effect of changing the roughness of the measuring plate on the obtained shear stress results. Controlled shear rate tests and Magneto Sweep measurements were carried out for three MR fluid layer heights. The tests were...
-
Water-Lubricated Journal Bearings Marine Applications, Design, and Operational Problems and Solutions
PublicationWater-Lubricated Journal Bearings: Marine Applications, Design, and Operational Problems and Solutions provides cutting-edge design solutions, common problems and methods for avoiding them, and material selection considerations for the use of water-lubricated journal bearings in marine environments. These bearings have many advantages, including the absence of the potential for oil contamination. They are also sensitive, and their...
-
CFD analysis of fluid flow through the labyrinth seal
PublicationSteam and gas turbines are some of the fundamental means of power generation. The energy efficiency of the turbines, however, is not satisfactory. Ever since the start-up of the first turbine in the world, engineers have been striving for their increased efficiency. Multiple solutions to the problem of steam loss in an operating turbine are available. The use of seals is one of them. Empirical methods or numerical calculations...
-
Design and computational fluid dynamics analysis of the last stage of innovative gas-steam turbine
PublicationResearch regarding blade design and analysis of flow has been attracting interest for over a century. Meanwhile new concepts and design approaches were created and improved. Advancements in information technologies allowed to introduce computational fluid dynamics and computational flow mechanics. Currently a combination of mentioned methods is used for the design of turbine blades. These methods enabled us to improve flow efficiency...
-
Should we seek further improvement of fluid film bearings - what for and how?
PublicationFluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient. Large bearings supporting shafts of huge and important rotating machines constitute a special group of fluid film bearings since the reliability of crucial systems, like for example electro-energetic system, rely on their trouble-free operation. Large thrust bearings, apart from enormous...
-
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,...
-
INFORMATION ABOUT DYNAMICS OF THE SEA SURFACE AS A MEANS TO IMPROVE SAFETY OF THE UNMANNED VESSEL AT SEA
PublicationOne of the fundamental states of the sea surface is its heave. Despite of years of the intense scientific inquiry, no clear understanding of the influence of this aspect on the dynamics of the sea environment has emerged. The separation of two nearby fluid elements which one may observed for example as a free floating of small objects on the sea surface (rescuers on the rough sea or small research vessels) is caused by the interaction...
-
Numerical investigation on the performance of a small counter-rotating wind turbine
PublicationThe article presents the results of the investigation on the performance of a small counter-rotating wind turbine. The wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in the computational domain. A parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance...
-
NUMERICAL ANALYSIS OF SPECIES DIFFUSION AND METHANOL DECOMPOSITION IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF Ni3Al FOR LOW REYNOLDS NUMBERS
PublicationNumerical modelling of hydrogen production by means of methanol decomposition in a thermocatalytic reactor using corrugated foil made of the Ni3Al intermetallic phase is shown in the paper. Experimental results of the flow analysis of mixtures containing helium and methanol in a thermocatalytic reactor with microchannels were used for the initial calibration of the CFD calculations (calculations based on the Computational Fluid...
-
Solid State Phenomena
Journals -
An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublicationPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
-
Cavitation Erosion Resistance Influence of Material Properties
PublicationThe cavitation erosion is the phenomena that causes degradation of fluid flow machinery components due to repetitive implosion of cavitation bubbles adjacent to the solid surface. Cavitation erosion is a complex phenomenon, which includes not only hydrodynamic factors of liquid, but also properties of erodible material e.g. microstructure, hardness or Young modulus. In order to reduce the negative impact of erosion on machine components,...
-
Influence of Fluid Compressibility and Movements of the Swash Plate Axis of Rotation on the Volumetric Efficiency of Axial Piston Pumps
PublicationThis paper describes the design of a swash plate axial piston pump and the theoretical models describing the bulk modulus of aerated and non-aerated fluids. The dead space volume is defined and the influence of this volume and the fluid compressibility on the volumetric efficiency of the pump is considered. A displacement of the swash plate rotation axis is proposed to reduce the dead space volume for small swash plate swing angles....
-
Modeling and simulation of blood flow under the influence of radioactive materials having slip with MHD and nonlinear mixed convection
PublicationRadioactive materials are widely in industry, nuclear plants and medical treatments. Scientists and workers in these fields are mostly exposed to such materials, and adverse effects on blood and temperature profiles are observed. In this regard, objective of the current study is to model and simulate blood based nanofluid with three very important radioactive materials, named as Uranium dioxide (UO2), Thorium dioxide (ThO2) and...
-
Selection Of Optimal Working Fluid For Use With Hybrid Microchannel-Microjet Heat Exchanger
PublicationThe paper presents the investigation to find best suited working fluid for a microjet- microchannel cooling module. In which microjets are impinging into the microchannels and forming a liquid film on the impingement surface. This technology takes benefits from two very attractive heat removal techniques. When laminar jets are impinging on the surface have a very high kinetic energy at the stagnation point, also in microchannels...
-
DETERMINATION OF SURFACTANTS IN ENVIRONMENTAL SAMPLES - PART I. CATIONIC COMPOUNDS = Oznaczanie Surfaktantów W Próbkach Środowiskowych. Część I. Związki Kationowe
PublicationCompounds from the group of cationic surfactants are widely applied in household, industrial, cleaning, disinfectant, cosmetic and pharmaceutical products as their specific properties (antimicrobial, emulsifying, anticorrosion, softening). After use, cationic surfactants are disposed to wastewater-treatment plants and finally with effluent water to surface waters due to their incomplete degradation. Moreover, they can freely circulate...
-
Comparative analysis of the theoretical models of ideal propulsor, ideal fluid brake, ideal screw propeller and ideal axial wind turbine
PublicationThe article presents a detailed discussion of four different fluid dynamics devices.These devices are presented with all relevant mathematical formulae regarding the forces, the power and the efficiency. It is demonstrated that application of the Betz theorem to axial wind turbines is not correct and it underestimates the maximujm achievable efficiency. This conclusion is supported by numerical calculations.
-
NON-STATIONARY THERMAL SELF-ACTION OF ACOUSTIC BEAMS CONTAINING SHOCK FRONTS IN THERMOCONDUCTING FLUID
PublicationNon-stationary thermal self-action of a periodic or impulse acoustic beam containing shock fronts in a thermoconducting Newtonian fluid is studied. Self-focusing of a saw-tooth periodic and impulse sound is considered, as well as that of a solitary shock wave which propagates with the linear sound speed. The governing equations of the beam radius are derived. Numerical simulations reveal that the thermal conductivity weakens the...
-
MOBILITY OF SHALE DRILL CUTTINGS CONSTITUENTS
PublicationThis study focuses on the abundance and mobility of metals and trace elements from shale drill cuttings into the water, being the main component of hydraulic fracturing fluid. The relationship between composition of the shale rock and the potential element release during standard water-based leaching tests was characterized by means of X-Ray Fluorescence spectroscopy (XRF). The XRF analysis confirmed the assumption of shales constituents...
-
AeroSense Measurements: Wind Tunnel EPFL
Open Research DataData from wind tunnel tests of Aerosesne measurement system installed on NACA63418 at EPFL wind tunnel.
-
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...
-
A Computational Analysis of the Aerodynamic and Aeromechanical Behavior of a Thermo-Well for Steam Temperature Measurement in a Steam Turbine
PublicationThe goal of the paper is twofold: firstly, it presents computational fluid dynamics analysis for finding maximum unsteady flow forces (and their frequencies) acting on a thermo-well for measuring steam temperature in a steam turbine control stage and secondly, it presents computational solid dynamics analysis of possibility of entry into resonance of the thermowell structure. There have been analyzed two cases of flow with changing...
-
THE THERMODYNAMIC ANALYSIS OF THE SZEWALSKI HIERARCHIC VAPOUR CYCLE COOPERATED WITH THE SYSTEM OF HEAT RECOVERY
PublicationIn this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperated with the system of heat recovery from exhaust gases are presented. According to that purpose, the CFM (Computation Flow Mechanics [1,3]) approach has correctly been used. The whole system consists of the first traditional steam cycle, the second organic Rankine cycle (ORC) and system of heat recovery with use of water with temperature 90...
-
Effect of free water on the quasi‑static compression behavior of partially‑saturated concrete with a fully coupled DEM/CFD approach.
PublicationThe work aims to numerically investigate the quasi-static response of partially fluid-saturated concrete under two-dimensional uniaxial compression at the mesoscale. We investigated how the impact of free pore fluid content (water and gas) affected the quasi-static strength of concrete. The totally and partially fluid-saturated concrete behavior was simulated using an improved pore-scale hydro-mechanical model based on DEM/CFD....
-
Study of Slip Effects in Reverse Roll Coating Process Using Non-Isothermal Couple Stress Fluid
PublicationThe non-isothermal couple stress fluid inside a reverse roll coating geometry is considered. The slip condition is considered at the surfaces of the rolls. To develop the flow equations, the mathematical modelling is performed using conservation of momentum, mass, and energy. The LAT (lubrication approximation theory) is employed to simplify the equations. The closed form solution for velocity, temperature, and pressure gradient...
-
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...