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Search results for: NUMERICAL ANALYSIS
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Estimation of the uncertainty of the LEM CV 3-500 transducers processing function
PublicationThe paper presents the methodology for estimating uncertainty of a voltage transducer processing function based on the example of LEM CV 3-500 transducer. The analysis was performed using the method based on the GUM Guide propagation of uncertainty law and the Monte Carlo numerical method. The article also presents a comparative analysis of the results of a voltage measurement evaluation done using the Monte Carlo simulation method,...
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Computational analysis of an infinite magneto-thermoelastic solid periodically dispersed with varying heat flow based on non-local Moore–Gibson–Thompson approach
PublicationIn this investigation, a computational analysis is conducted to study a magneto-thermoelastic problem for an isotropic perfectly conducting half-space medium. The medium is subjected to a periodic heat flow in the presence of a continuous longitude magnetic field. Based on Moore–Gibson–Thompson equation, a new generalized model has been investigated to address the considered problem. The introduced model can be formulated by combining...
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A novel sandwich footbridge - Practical application of laminated composites in bridge design and in situ measurements of static response
PublicationA novel sandwich composite footbridge is presented in the paper, as an example of practical application of laminated composites in civil engineering. The in situ static load tests of the footbridge before its acceptation for exploitation are shown and discussed. The results are compared with the corresponding ones from a numerical equivalent single layer model of the sandwich structure created within the framework of finite element...
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Dynamic effect of the vehicle passing under lightweight footbridge.
PublicationThe paper describes a numerical study of dynamic response of cable-stayed steel footbridge for a big lorry passing underneath. The footbridge is an existing object crossing Wolska street in Warsaw. The structural model of footbridge was verified by dynamic test loading. A numerical study of a vehicle passing under footbridge is presented. 2D and 3D incompressible flow fields are modeled using sliding mesh in transient CFD computation....
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Trees as a solar control measure for southern-oriented street frontages. Analysis of a selected street model for a humid continental climate
PublicationThe present study is aimed at the analysis of possibilities for shading southern frontage of street oriented along the E-W axis by the single row of trees, parallel to the southern elevations. The effectiveness of solar control shading was tested depending on the geometric relationships between trees and buildings. Numerical simulation analyses were conducted in Rhinoceros® program for the street located in humid continental climate...
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Hybrid geothermal-fossil power cycle analysis in a Polish setting with a focus on off-design performance and CO2 emissions reductions
PublicationGrowing demand for electricity due to economic development contributes to increased greenhouse gas production, especially CO2. However, emissions can be limited by enhancing the efficiency of primary energy conversion, such as integrating geothermal energy into coal-fired power plants. Therefore, this paper proposes replacing conventional feed-water heaters with geothermal preheaters to create a hybridized system. This study was...
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The influence of brace to chord rotational connection stiffness on stability of the truss
PublicationThe paper is devoted to the numerical analysis of the roof truss subjected to upward wind loading and braced at the tensioned top chord. The linear buckling analysis were performed for the beam and shell model of the structure. As the result the influence of rotational connection stiffness between the brace and the top chord on the truss stability was appointed. The biaxial strength testing machine was used to conduct the experimental...
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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Nonreciprocal Devices Utilizing Longitudinally Magnetized Ferrite Coupled Lines
PublicationThis chapter presents authors’ recent research on the nonreciprocal devices utilizing longitudinally magnetized ferrite coupled line (FCL) junction. The principle of operation of FCL junction is explained and the hybrid techniques of analysis are shown. Numerical and experimental results concerning the nonreciprocal devices utilizing the different configurations of FCL junctions are presented and discussed.
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Enhancement of the Brayton cycle efficiency by water or steam utilization
PublicationIn the paper, thermodynamic analysis of two modifications of a Brayton cycle into enhancement cycles with water/steam injection are discussed. The first one deals with a STIG modified system with both interstage compressed air cooling and air heating (heat regeneration) before combustion chamber. The second one, mainly devoted to higher steam/air ratio, is connected with separate steam production in a HRSG. The analysis has been...
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Improving Savonius rotor performance by shaping its blade edges
PublicationThe article presents the results of the numerical analysis of the flow inside the Savonius rotor. Particular at-tention has been paid to the vicinity of the blade gap in order to recognise the mechanisms controlling the flow in this area. The conclusions resulting from the analysis made the basis for an attempt to improve Savonius turbine performance via shaping rotor blade edges. The paper presents selected characteristic flow...
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An absorbing set for the Chialvo map
PublicationThe classical Chialvo model, introduced in 1995, is one of the most important models that describe single neuron dynamics. In order to conduct effective numerical analysis of this model, it is necessary to obtain a rigorous estimate for the maximal bounded invariant set. We discuss this problem, and we correct and improve the results obtained by Courbage and Nekorkin (2010). In particular, we provide an explicit formula for an...
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Numerical simulations of space-time conditional random fields of ground motions
PublicationArtykuł przedstawia metodę modelowania stochastycznego efektu propagacji fali sejsmicznej z wykorzystaniem przestrzenno-czasowej funkcji korelacji pola losowego trzęsienia ziemi. Metodę wykorzystano do generacji nieznanych historii czasowych trzęsienia w wybranych punktach na podstawie znanego rejestru w jednym miejscu. Wyniki pokazały, iż zastosowanie zaproponowanej metody prowadzi do relatywnie małych błędów symulacji.
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Numerical estimation of flood zones in the Vistula River valley, Warsaw, Poland
PublicationPrzedstawiono studium dotyczące wyznaczenia stref zagrożenia powodziowego dla miasta Warszawy wskutek wezbrań rzeki Wisły. Do oszacowania zasięgu stref wykorzystano matematyczny model ustalonego przepływu wolnozmiennego oraz numeryczny model terenu doliny rzeki. Do zobrazowania uzyskanych wyników zastosowano system GIS. Na podstawie uzyskanych wyników zidentyfikowano obszary miasta Warszawy narażone na ewentualną powódź oraz odcinki...
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Technical fabrics in costruction of large scale roofs - numerical and experimental aspects
PublicationDesigning and construction of textile hanging roofs is the challenging subject for engineers. This type of structure needs geometrically and very often also physically non-linear calculations. Due to different behaviour of two families of threads (warp and weft), which during deformation can change the angle between their directions, they require special constitutive modelling. Also the loading of hanging roofs is very special....
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Numerical Simulation of Electron Beam Welding Process of Inconel 706 Sheets
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Numerical modelling of water transport processes in partially-connected tidal basins
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A new insight into understanding the Crow and Champagne preferred mode: a numerical study
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Numerical and behavioral responses of waterfowl to the invasive American mink: A conservation paradox
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Representation of a built-up area in the numerical simulation of urban flash flooding
PublicationPrzedstawiono wyniki modelowania powodzi miejskiej przy pomocy dwuwymiarowych równań de Saint-Venanta. Równania rozwiązano metodą objętości skończonych. Zaprezentowano dwie techniki reprezentacji obszarów zabudowanych w numerycznej symulacji powodzi - bezpośrednie wykluczenie budynków z siatki numerycznej oraz zastąpienie grup budynków terenami o znacznie zwiększonej szortkości powierzchni. W celu oceny wykorzystanych metod wykonano...
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Numerical simulation of threshold-crossing problem for random fields of environmental contamination
PublicationCelem artykułu jest analiza szacowania prawdopodobieństwa, że pole losowe zanieczyszczeń nie przekracza pewnej wartości w danej dwuwymiarowej przestrzeni. W analizie wykorzystano metodę modelowania stochastycznego wykorzystując procedurę symulacji warunkowej. Opisany przykład praktycznego zastosowania metody dotyczy pola zanieczyszczenia metalami ciężkimi gruntu w regionie gdańskim.
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New method of processing heat treatment experiments with numerical simulation support
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Numerical investigation of the core eccentricity effect on wave propagation in embedded waveguide
PublicationThe paper presents results of theoretical and numerical investigation of guided wave propagation in two-layer bars with geometric imperfections in the form of eccentric location of steel core. Steel rod of diameter equal to 1 cm embedded in composite mortar-type cover with external diameter equal to 5 cm has been taken into consideration. Several different rods with variable size of eccentricity are analysed. Results for rods with...
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Numerical single-phase modeling of turbulent flow and heat transfer of nanofluids
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (6 000< Re < 12 000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with published experimental data.
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Thermal ablation modeling via the bioheat equation and its numerical treatment
PublicationThe phenomenon of thermal ablation is described by Pennes’ bioheat equation. This model is based on Newton’s law of cooling. Many approximate methods have been considered because of the importance of this issue. We propose an implicit numerical scheme which has better stability properties than other approaches.
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A method for the accurate numerical prediction of the tip vortices shed from hydrofoils
PublicationPraca przedstawia wyniki obliczeń numerycznych rozkładu wirowości i pól prędkości w przekrojach wirów wierzchołkowych generowanych przez płaty nośne. Obliczenia przeprowadzono przy pomocy nowej, wyspecjalizowanej metody dyskretyzacji obszaru przepływu. Rezultaty obliczeń porównano z wynikami pomiarów anemometrem laserowym za modelami płatów w tunelu kawitacyjnym. Porównanie to potwierdziło skuteczność nowej metody dyskretyzacji...
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The Numerical Comparison of Heat Transfer in a Coated and Fixed Bed of an Adsorption Chiller
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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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RMS-based damage detection in reinforced concrete beams: numerical simulations
PublicationImage-based damage detection methods using guided waves are well known and widely applied approaches in structural diagnostics. They are usually utilized in detection of surface damages or defects of plate-like structures. The article presents results of the study of applicability of imaging wave-based methods in detection in miniscule internal damage in the form of debonding. The investigations were carried out on numerical models...
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Entanglement of genuinely entangled subspaces and states: Exact, approximate, and numerical results
PublicationGenuinely entangled subspaces (GESs) are those subspaces of multipartite Hilbert spaces that consist only of genuinely multiparty entangled pure states. They are natural generalizations of the well-known notion of completely entangled subspaces, which by definition are void of fully product vectors. Entangled subspaces are an important tool of quantum information theory as they directly lead to constructions of entangled states,...
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A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
PublicationThe ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants...
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Numerical calculations of behaviour of ship double-bottom structure during grounding
PublicationIdeą projektu CORET jest dodanie do obecnej konstrukcji dna podwójnego statku specjalnych powłok polimerowo-betonowych w celu zwiększenia odporności na rozszczelnienie podczas kolizji, czy wejścia na mieliznę. Aby poprawnie zaprojektować te bariery ochronne konieczne jest przeprowadzenie symulacji numerycznej. Tworzenie modelu numerycznego konstrukcji podczas kolizji jest bardzo złożone i wymaga wykonania symulacji pomocniczych...
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Verification of geotechnical numerical simulations by model tests using PIV technique
PublicationPrzedstawiono metodykę i wyniki badań modelowych stateczności fundamentów bezpośrednich posadowionych w sąsiedztwie kątowych ścian oporowych. Dla takiego złożonego układu fundament - obciążenie - podłoże gruntowe wykonano badania modelowe w płaskim stanie odkształcenia na gruncie naturalnym i analogowym. Trajektorie i izopola przemieszczeń oraz progresywny rozwój kształtu i zasięgu powierzchni poślizgu określono techniką PIV.
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Numerical weather prediction - data fusion to GIS systems and potential applications
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Numerical simulations of transonic flow with film cooling and jet vortex generators
PublicationW pracy przedstawiono wyniki obliczeń przepływu transonicznego na stronie ssącej łopatki turbiny gazowej. Obliczenia wykonano dla geometrii komory pomiarowej w tunelu transonicznym IMP PAN, zaprojektowanej tak, aby odwzorować warunki przepływowe istniejące w palisadzie turbinowej. Przedstawiono wyniki obliczeń przepływu z zastosowaniem otworów chłodzących (film cooling) oraz strumieniowych generatorów wirów. Porównano je z danymi...
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Numerical Simulation of two dimensional flow past a bridge cross section
PublicationThis work presents some numerical results concerning application of CFD in civil engineering problems. Selected theoretical aspects of fluid mechanics are elucidated. In the second part of the paper a cross section of upper footbridge of the Bella Sky Hotel in Copenhagen is analysed numerically in the field of wind action.
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Experimental and numerical evaluation of mechanical behaviour of composite structural insulated panels
PublicationComposite structural insulated panels (CSIPs) are novel prefabricated elements for structural applications. Panels under consideration are made from glass-fibre reinforced magnesia cement boards as facesheets and expanded polystyrene foam (EPS) as a core. Quasi-static full-scale and model bending tests under monotonic loading were performed to recognize mechanical properties of CSIPs in flexure. In addition, tensile, compressive,...
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Experiments and numerical modeling of meat and bone meal pyrolysis in a rotary kiln
PublicationThe paper presents aspects of modelling the pyrolysis of meat and bone meal (MBM) in a rotary kiln. The pyrolysis of MBM produces a solid fraction which can be used as a fuel, a liquid fraction with potential chemical applications and a low heating value gas. The meat and bone meal pyrolysis was carried out at the temperature of 900 oC. Main features of experiments and numerical model of the pyrolysis were described. The model...
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Numerical modelling of moored floating structures using SPH. Preliminary results
PublicationThis article presents partial results of the works carried out under the research project "The development of the methodof modeling the dynamics of the floating (offshore) objects subjected to the environment influence", which aims at developing computational methods for modeling the dynamics of offshore structures.The article contains the description of the method of modeling the hydrodynamic impacts using SPH method and the description...
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Model research and numerical calculations of the buoy for capturing of the sea-waves energy
Publicationw pracy przedstawiono konstrukcję i zasadę działania modelu 1:5 boi do pozyskiwania energii fal morskich oraz wyniki badań eksperymentalnych prowadzonych w dużym basenie w Centrum techniki Okrętowej w Gdańsku.Ponadto przedstawiono numeryczny model obliczeniowy i wybrane wyniki symulacji zachowania się boi na fali regularnej.
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Numerical modeling of GPR field in damage detection of a reinforced concrete footbridge
PublicationThe paper presents a study on the use of the ground penetrating radar (GPR) method in diagnostics of a footbridge. It contains experimental investigations and numerical analyses of the electromagnetic field propagation using the finite difference time domain method (FDTD). The object of research was a reinforced concrete footbridge over a railway line. The calculations of the GPR field propagation were performed on a selected cross-section...
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Multi-core and Multiprocessor Implementation of Numerical Integration in Finite Element Method
PublicationThe paper presents techniques for accelerating a numerical integration process which appears in the Finite Element Method. The acceleration is achieved by taking advantages of multi-core and multiprocessor devices. It is shown that using multi-core implementation with OpenMP and a GPU acceleration using CUDA architecture allows one to achieve the speedups by a factor of 5 and 10 on a CPU and GPUs, respectively.
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Numerical simulation of screw displacement pile interaction with non-cohesive soil
PublicationA trial numerical simulation of screw displacement pile interaction with non-cohesive subsoil during the transfer of compression load. The simulation was carried out in an axisymmetric system. The technological phases of pile installation in the ground were numerically modelled using equivalent processes which provided similar effects to real technical actions. The results of the numerical calculations were verified by comparing...
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RADIATION OF HIGH INTENSITY SOUND BY CIRCULAR DISC BY MEANS OF THE NUMERICAL METHOD
PublicationThe main goal of this paper is to find sound pressure distribution radiated by the circular piezoelectric disc that vibrates with the finite amplitude. There has been presented the pressure distribution close to the radiating surface. Also it is shown the sound pressure distribution in the 3D form. The mathematic modeling was carried out on the base of the nonlinear acoustic equation with the proper boundary condition. The axial...
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Novel Analytic-Numerical Model of Free Convection: with Leading Edge Considered
PublicationA novel solution of the free convection boundary problem is represented in analytical form for velocity and temperature for an isothermal vertical plate, as an example. These fields are built as a Taylor Series in the x coordinate with coefficients as functions of the vertical coordinate (y). We restrict ourselves by cubic approximation for both functions. The basic Navier-Stokes and Fourier-Kirchhoff equations and boundary conditions...
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Numerical simulation of behaviour of thin-walled frames subjected to static loads
PublicationArtykuł poświęcony jest problemowi zachowania się ramy, zbudowanej z elementów cienkościennych o przekroju bisymetrycznym obciążonej momentem skręcającym.
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Some remarks about numerical conditioning of discrete time Riccati eqations.
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Numerical approximation of first order partial differential equations withdeviated variables.
PublicationKlasyczne rozwiązania nieliniowego zagadnienia Cauchy´ego określone na piramidzie Haara są aproksymowane za pomocą rozwiązań układów quasiliniowych równań różnicowych. Stabilność schematu różnicowego jest wykazana metodą porównawczą z zastosowaniem nieliniowych oszacowań typu Perrona dla danych funkcji. Podano przykłady numeryczne.
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Numerical contribution to the viscoelastic magnetic lubrication of human joint in periodic motion.
PublicationPraca przedstawia rozwiązania problemu smarowania stawów człowieka w układzie współrzędnych ortogonalnych krzywoliniowych dla ruchu nieustalonego okresowego w polu magnetycznym. Uwzględnia się lepkosprężyste właściwości cieczy synowialnej w trakcie smarowania
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Numerical modelling of elasto-viscoplastic Chaboche constitutive equations using MSC.Marc.
PublicationArtykuł omawia wykorzystanie specjalnej procedury UVSCPL umożliwiającej wprowadzenie do komercyjnego programu MSC.Marc sprężysto-lepkoplastycznych równań modelu Chaboche'a. Prezentuje szereg przykładów numerycznych, które potwierdzają poprawność zaproponowanej koncepcji analizy konstrukcji z wykorzystaniem rozpatrywanego prawa Chaboche'a ze zniszczeniem.