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Search results for: MCREYNOLDS CONSTANTS.
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Discrete-continuous optimisation of an axial flow blood pump
PublicationThis paper presents results of discrete-continuous optimisation of an axial flow blood pump. Evolution Strategies (ES) are used as a global optimisation method in order to localise the optimal solution in relatively short time. The whole optimisation process is fully automated. This also applies to geometry modelling. Numerical simulations of the flow inside the pump is performed by means of the Reynolds-Average Navier-Stokes...
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Thermodynamic and geometrical characteristics of mixed convection heat transfer in the shell and coil tube heat exchanger with baffles
PublicationThe article presents passive heat transfer enhancement method in the form of baffles to increase the energy efficiency of the shell coil heat exchanger. Conducted literature review shows that, despite numer- ous studies, there is little work on the intensification of heat transfer at the shell side. Most of the work focuses on the impact of geometrical parameters of the coil itself. This article successfully proves that it is possible...
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The Discrete-Continuous, Global Optimisation of an Axial Flow Blood Pump
PublicationThis paper presents the results of the discrete-continuous optimisation of an axial flow blood pump. Differential evolution (DE) is used as a global optimisation method in order to localise the optimal solution in a relatively short time. The whole optimisation process is fully automated. This also applies to geometry modelling. Numerical simulations of the flow inside the pump are performed by means of the Reynolds-Average Navier-Stokes...
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The assessment of metrological properties of segmental orifice based on simulations and experiments
PublicationSegmental orifices are often used to measure flows of heterogeneous mixtures, especially in flow meters in the power industry, for example. The orifice (with module m= 0.25) was installed in a stainless-steel pipe with internal diameter of 50 mm, placed in a hydraulic water system. The research was performed for Reynolds numbers ranging from 9,000 to 17,000. The flow characteristics of this orifice obtained based on simulation...
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Analysis of magnetic field distribution inside ferromagnetic thin shells during degaussing process
PublicationAnalysis of the demagnetization of a large ferromagnetic object like a ship, was conducted. The approximate mathematical model in the form of a long cylindrical shell of constant magnetic permeability was applied. The discrete degaussing winding was assumed and the current density and magnetic flux density distribution in the ferromagnetic shell wall were determined. Based on the frequential and temporal analysis the recommended...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K09A - full-run
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K09 - pre-run
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K05
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K08
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K02
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K06
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K07
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15,...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K03
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K04
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180...
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VIbration monitoring in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K01
Open Research DataVIbration monitoring in reciprocating siding friction tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180...
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Structure elucidation of carbamoylo-β-lactam diastereoisomers by ROESY and NOESY experiments
PublicationRecently we have focused in the problem of preparation of carbamoylo-β-lactams as a result of oxidative cyclization of malonyl enamides. In our experiments we obtain mixture of two main β-lactam products: as a result of subsequent elimination and a second as a product of substitution. All of the produced β-lactams have trans configuration what was confirmed by 1H coupling constants. However id should be stressed that in the case...
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Damian Rosiak dr inż.
PeopleEducation 2010–2014: Gdansk University of Technology, Chemical Faculty (Eng.) field of study: biotechnology specialty: drug biotechnology 2014–2015: Gdansk University of Technology, Chemical Faculty (M.Sc.) field of study: biotechnology specialty: drug biotechnology 2015–2020: Gdansk University of Technology, Department of Inorganic Chemistry (Ph.D.) discipline: chemical sciences specialty: inorganic chemistry Scientific...
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Measurements of relative frequency instability
PublicationFrequency constancy can be determined by the change in time for the subsequent periods. The article shows that classical the method of digital period measurement is not suitable for the measurement process. Therefore, a method using an integrating circuit is being proposed. Errors in the measurement of the given method have been analyzed.
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Magnetizabilities of relativistic hydrogenlike atoms in some arbitrary discrete energy eigenstates
PublicationWe present the results of numerical calculations of magnetizability of the relativistic hydrogenlike atoms. Exploiting the analytical formula for $\chi$ we have found the values of the magnetizability for the ground state and for the first and the second set of excited states of the atom. The results for ions with the atomic number $0
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A study of the photoelectron spectra of α-tetrahydrofurfuryl alcohol over the outer valence energy region (9–25 eV)
PublicationPhotoelectron spectra of α-tetrahydrofurfuryl alcohol (THFA) molecules, the threshold spectrum and spectra for constant photoelectron energies, have been measured over the photon energy range 9–25 eV. Analysis of the photoelectron spectra has allowed overlapping photoionization bands to be separated, tentatively assigned and their vertical photoionization energies to be determined. These energies are compared with existing theoretical...
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The AFM micrographs of gold nanoparticles on silicon substrate
Open Research DataThe dataset contains the first approach towards AFM topographic imaging of gold nanoparticles synthesized and immobilized on the silicon surface. Measurements were made in the semi-contact mode on the NTEGRA Prima device, manufactured by NT-MDT. Scans were performed with amplitude detection at an operating value of 60% of the free oscillation amplitude....
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Estimation of Conservative Contaminant Travel Time through Vadose Zone Based on Transient and Steady Flow Approaches
PublicationEstimation of contaminant travel time through the vadose zone is needed for assessing groundwater vulnerability to pollution, planning monitoring and remediation activities or predicting the effect of land use change or climate change on groundwater quality. The travel time can be obtained from numerical simulations of transient flow and transport in the unsaturated soil profile, which typically require a large amount of data and...
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Influence of silver-core gold-shell nanoparticle parameters on the variation of surface-enhanced Raman spectra
PublicationThe detection of molecules by surface-enhanced Raman spectroscopy (SERS) is dependent on the nanomaterial used to induce the enhancement effect. This depends on a variety of parameters of the substrate such as the metal used for their creation, their shape, size and size distribution, concentration, as well as the parameters of the solution, such as packing of the nanoparticles, the complexity of the sample, the solvent, etc. It...
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Stable nanoconjugates of transferrin with alloyed quaternary nanocrystals Ag–In–Zn–S as a biological entity for tumor recognition
PublicationOne way to limit the negative effects of anti-tumor drugs on healthy cells is targeted therapy employing functionalized drug carriers. Here we present a biocompatible and stable nanoconjugate of transferrin anchored to Ag-In-Zn-S quantum dots modified with 11-mercaptoundecanoic acid (Tf-QD) as a drug carrier versus typical anticancer drug, doxorubicin. Detailed investigations of Tf-QD nanoconjugates without and with doxorubicin...
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Some Aspects of Shear Behavior of Soft Soil–Concrete Interfaces and Its Consequences in Pile Shaft Friction Modeling
PublicationThis paper examines the stiffness degradation and interface failure load on soft soil–concrete interface. The friction behavior and its variability is investigated. The direct shear tests under constant normal load were used to establish parameters to hyperbolic interface model which provided a good approximation of the data from instrumented piles. Four instrumented piles were used to obtain reference soil–concrete interface behavior....
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Novel microstrip low-pass filters with fractal defected ground structures
PublicationIn this study, three microstrip low-pass filters (LPFs) containing fractal-shaped defected ground structures have been designed and manufactured. To improve the performance of microstrip LPF, cascades of inductively coupled fractal resonators have been applied. Simultaneously, to achieve relatively constant microstrip impedance resulting in essentially low reflection losses, a modification of the strip geometry has been introduced....
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On-Line Partitioning for On-Line Scheduling with Resource Conflicts
PublicationWithin this paper, we consider the problem of on-line partitioning the sequence of jobs which are competing for non-sharable resources. As a result of partitioning we get the subsets of jobs that form separate instances of the on-line scheduling problem. The objective is to generate a partition into the minimum number of instances such that the response time of any job in each instance is bounded by a given constant. Our research...
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The σ-phase superconductors Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9
PublicationWe show that the previously unreported ternary σ phases Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9 are both superconductors with Tc values of approximately 1.9 K. The superconducting transitions were characterized through temperature-dependent magnetic susceptibility, electrical resistance, and specific heat measurements. The Sommerfeld constants, γ, for Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9 are 89(1) mJ mol-f.u.−1K−2 and 86(1) mJ mol-f.u.−1K−2...
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Simultaneous Removal of Al, Cu and Zn Ions from Aqueous Solutions Using Ion and Precipitate Flotation Methods
PublicationThis paper presents the results of investigations concerning the simultaneous removal of Al(III), Cu(II), and Zn(II) from dilute aqueous solutions using ion and precipitate flotation methods. The effects of initial solution pH, surface active substance concentration, and the gas velocity on the flotations’ efficiency and course are studied. Experimental results are discussed in terms of physicochemical aspects related to aqueous...
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Mineral and Organic Matter Constituents in Weak Interfaces in Shales
PublicationThis paper identifies formation interfaces that would appear to be "weak interfaces", in the Jurassic, Early- Cretaceous Vaca Muerta formation, in the Neuquén Basin, Argentina. Significant distribution of the weak interfaces was observed including contacts between volcanic ash layers of varying thicknesses, calcite-filled veins, and contacts between lithology changes, such as between argillaceous mudstone and mottled carbonates....
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Dead-Time Effect Compensation Based on Additional Phase Current Measurements
PublicationThis paper proposes a new method of dead-time effect compensation. The proposed solution is based on additional phase current measurements realized by analog-to-digital converters. These measurements are carried out at the time instants specified by a pulsewidth-modulation (PWM) strategy. This makes it possible to estimate inverter currents at the commutation instants and, finally, to estimate the voltage error caused by dead time. This...
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Effect of Nb and Al on in vitro dissolution behavior and structure of Na2O-MgO CaO-P2O5 glasses
PublicationIn vitro dissolution, structure, and thermal properties of the glass series Na2O-MgOsingle bondCaOsingle bondNb2O5 -Al2O3-P2O5 were studied. The dissolution behavior in phosphate-buffered saline (PBS) confirmed the potential bioactive properties of tested glasses. The dissolution process was found to depend on the Al, Nb, and Mg contents. Al, respectively, suppresses the Nb and accelerates the Mg release process from the glasses....
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Study on Strategy in University Laboratory Class Teaching
PublicationLaboratory teaching is a critical way to ensure the effective input of techniques in engineering learning. Laboratory teaching not only contributes to improving course quality but also helps enrich comprehensive engineering application ability. However, there are some typical problems in current university laboratory teaching, such as rigid and isolated course design, outdated contents and materials, and not encouraging innovation...
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ANALIZA POSTAW INTERNAUTÓW WOBEC MARKI W MEDIACH SPOŁECZNOŚCIOWYCH
PublicationCelem opracowania jest ukazanie roli, jaką odgrywają media społecznościowe i wypowiedzi internautów w kształtowaniu wizerunku marki wśród użytkowników Sieci. Artykuł prezentuje także wyniki obserwacji aktywności polskich internautów dotyczące jednej z polskich marek spożywczych. Internauci zamieszczają w Internecie różnorodne treści powiązane pośrednio lub bezpośrednio z markami. Zadaniem organizacji, podobnie jak w przypadku pozostałych...
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A new approach to active noise and vibration control - [Part II: unknown frequency case]
PublicationThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly timevarying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. It is not assumed that a...
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Fuel systems of high power stationary engine
PublicationThe use of alternative fuels and, in the future, synthetic fuels has forced changes in the design of fuel supply systems in internal combustion engines. When operating a stationary engine at constant load, the possibility of using lean fuel mixtures appears. The selection of a precise operating mixture ignition system requires changes in traditional fuel systems. The article presents the current designs of fuel supply systems and...
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Research on the wear evenness of the tool in flat lapping
PublicationIn this paper, the dimensionless distribution of the material removal stock and the trajectories of abrasive grains cutting in single-sided lapping process are presented. They were numerically simulated based on the tribological model and kinematics equations. It can be observed that the trajectories geometry of single abrasive as well the velocities have a great influence on the final geometrical deviation. During machining, the...
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Sulfur compounds: Gas chromatography
PublicationSulfur compounds, due to their properties, are responsible for the damage of our environment. For this reason sulfur containing compounds are of constant concern in many fields. Gas chromatography (GC), due to combination of separation capability and sensitive detection is a prime technique for the analysis of thes compounds in various matrices. The chapter rewies general problems of the determination of these compounds by GC and...
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A study of the electronic states of pyrimidine by electron energy loss spectroscopy
PublicationThe electron energy loss spectra were measured in pyrimidine at the constant electron residual energy varied from 15 meV to 10 eV and in the scattering angle range 0–180°. The spectra were analysed applying an iteration fitting procedure to resolve the energy loss bands corresponding to excitation of the electronic states of pyrimidine. The vertical excitation energies of the singlet states of pyrimidine and of a number of the...
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Influence of the Square Wave Voltage on Dynamical Properties of a Flat Voltammetric Electrode in the Time Domain by the Electrochemical Reversible Reaction
PublicationIn this article there is a presentation of the analysis of the polarizing voltage shape influencing dynamic properties of voltammetric electrodes when on their surface reversible reaction takes place in the time domain. The electrode polarization with linearly increasing voltage and with a square component, was analyzed. The analysis that were conducted showed that the voltammetric electrode behaves like a first order transducer....
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Errors of a Linear Current Approximation in High-Speed PMSM Drives
PublicationCurrent sampling techniques and predictive algorithms used in the digital control of electric drives rely on a simple mathematical model that assumes linear current changes upon constant supplying voltages. This paper identifies rotor movement as a factor that makes this assumption invalid when the rotor covers an angular distance of a few tens of degrees during the control interval duration. The errors of the linear current approximation...
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Small rov to detection and identification of dangerous underwater objects
PublicationA small unmanned underwater vehicle (UUV) to inspection of an undersea space is presented in the paper. Its behavior is controlled by a trained pilot. Correct detection and identification of targets depends on vehicle'sprecise displacement along a predefined route. Nowadays, the UUVs are equipped with an automatic control system to execute some basic maneuvers without constant human interventions. Hence, in the paper, an autopilot...
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Reaction quotients of reforming reactions for SOFC and SOFC with LSCNT layer fueled by biogas mixture at 750 C - longterm
Open Research DataThe dataset contains the calculated reaction quotients of reforming reactions for the SOFC and SOFC with LSCNT layer (La0.27Sr0.54Ce0.09Ni0.1Ti0.9O3-s) fueled by synthetic biogas mixture (60:40 CH4:CO2). The outlet concentration of the gases from SOFC were measured using novel FTIR-based unit.
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Forming of the gap in tendon sutures with the Kessler suture
Open Research DataThe main objective of the all study was to assess the load capacity of a new implant device for knotless tendon anastomosis. During this series of experiments the gap formation process between the fronts of the connected tendons was observed. Tendons from fresh swine legs (commercially available) served as the biological material. The tendon juncture...
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Navier number and transition to turbulence
PublicationThe motivation behind this article is to explain a role of the Navier number (Na -dimensionless slip-length) in prediction of closures for laminar to turbulent transition undergoing via eddies detachment from the slip layer in nano-cannals. Additionally the role of the Navier number Na in universal modeling of phenomenon of enhanced mass flow rate reported in micro- and nano-channels has been explained. The Na number should be...
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An advanced Thermal-FSI approach to flow heating/cooling
PublicationActually, two-way thermal-energy exchange between working fluid and solid material of a casing is a leading problem for modern – semi automatic – design techniques. Many questions should be solved, especially, the turbulent mode of thermal energy transport both in fluid and solid, should be re-examined and reformulated from the primary principles. In the present paper, a group of researchers from Energy Conversion Department of...
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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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Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublicationA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
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TIME-DOMAIN NUMERICAL EVALUATION OF SHIP RESISTANCE AND MOTION IN REGULAR WAVES BY USING THE CFD URANS METHOD
PublicationTaking into account the International Maritime Organisation’s (IMO) strategy to radically reduce the GHG emitted by the shipping industry towards zero emission operation, today's assessment of ship behaviour in waves, its seakeeping characteristics and resistance and their interrelation with fuel consumption and emissions are one of the most attended research subject. There are three methods to conduct this analysis, which are...
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Możliwości wydłużania krzywych przejściowych w układach geometrycznych torów
PublicationW pracy przedstawiono analizę problemu wydłużania krzywych przejściowych, wykorzystując do tego celu analityczną metodę projektowania. Podstawę analizy stanowiły obliczenia numeryczne przeprowadzone dla zestawu parametrów charakteryzujących standardowy układ geometryczny: krzywa przejściowa – łuk kołowy – krzywa przejściowa (w wersji niesymetrycznej). Ocenie poddano różnice rzędnych poziomych układu istniejącego oraz układu z...