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Search results for: WIND TURBINE, OFFSHORE, FEA, MODAL ANALYSIS, DYNAMIC COUPLING, SENSITIVITY ANALYSIS, DESIGN OF EXPERIMENT, RESPONSE SURFACE METHOD.
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Modal FEM Analysis of Ferrite Resonant Structures
PublicationThe finite-element method (FEM) is applied for modal analysis of ferrite-loaded spherical resonators. To improve the efficiency of the numerical calculations, the body-of-revolution (BOR) technique is utilized. Due to the frequency-dependent ferrite permeability, FEM leads to a nonlinear eigenvalue problem that is challenging to solve. To this end, Beyn’s method is proposed. The effectiveness of the proposed approach is confirmed...
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Material Parameters Identification of Historic Lighthouse Based on Operational Modal Analysis
PublicationIn the present paper, the identification of the material parameters of a masonry lighthouse is discussed. A fully non-invasive method was selected, in which the material properties were determined via numerical model validation applied to the first pair of natural frequencies and their related mode shapes, determined experimentally. The exact structural model was built by means of the finite element method. To obtain experimental...
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AN EXPERIMENTAL AND NUMERICAL STUDY ON THE PERFORMANCE OF AN INNOVATIVE VERTICAL-AXIS WIND TURBINE
PublicationThis paper introduces the innovative modification of the Savonius wind turbine being able to significantly increase efficiency in comparison with the classic design. This innovative design is equipped with a stator directing the flow. The presence of the stator increases the active surface area and generates higher torques acting on a shaft. Additionally, it makes it possible to take better advantage of wind energy and compensate...
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Modal Reduction and Analysis of Gyroscopic Systems
PublicationThe paper introduces the method of the modal reduction of systems that experience the Coriolis acceleration or gyroscopic effect component. In such cases corresponding system equations are non-self-adjoined. To solve the problem modal reduced model is built up for the system without Coriolis acceleration or gyroscopic effect terms. These phenomena are included by application of any lumping technique. Hence, the final reduced model...
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Control of the wind turbine generator
PublicationWind power system consists of two main parts: wind turbine and electrical generator. Wind turbine converts the energy of the flowing air into mechanical energy, next generator converts this energy into electrical energy that is sent to the power system. These two processes should be realized with maximum efficiency and the following requirements for the control system can be formulated: opti-mal wind power conversion, compensation...
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Composite sandwich footbridge—measured dynamic response vs. FEA
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Flow Analysis of a Kaplan Turbine
PublicationThis monograph is a guide to a method of experimental and numerical flow investigations for Kaplan - type turbines. The numerical calculations were compared with the test results of the model Kaplan turbine. The tests were carried out on the model test rig in the Gdańsk University of Technology. The turbine has been thoroughly experimentally investigated, resulting in the identification of optimum setting combination of the stator...
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Design analysis of combined gas-vapour micro power plant with 30 kW air turbine
PublicationThe article presents basic results of the design analysis of a combined gas-vapour micro power plant with a waste-heat boiler without exhaust reheat, working in the vapour section in the Organic Rankine Cycle (ORC) system. The analysis concerned working media most frequently used in those types of power plants and planned to be used in future. The object of the analysis was a micro power plant with a 30 kW gas (air) turbine for...
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Design analysis of combined gas-vapour micro power plant with 30 kW air turbine
PublicationThe article presents basic results of the design analysis of a combined gas-vapour micro power plant with a waste-heat boiler without exhaust reheat, working in the vapour section in the Organic Rankine Cycle (ORC) system. The analysis concerned working media most frequently used in those types of power plants and planned to be used in future. The object of the analysis was a micro power plant with a 30 kW gas (air) turbine for...
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Investigation of the aerodynamics of an innovative verticalaxis wind turbine
PublicationThis paper presents a preliminary three dimensional analysis of the transient aerodynamic phenomena occurring in the innovative modification of classic Savonius wind turbine. An attempt to explain the increased efficiency of the innovative design in comparison with the traditional solution is undertaken. Several vorticity measures such as enstrophy, absolute helicity and the integral of the velocity gradient tensor second invariant...
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A higher order transversely deformable shell-type spectral finite element for dynamic analysis of isotropic structures
PublicationThis paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various...
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Dynamic analysis of the impact of the wind spectrum according to the theory of Davenport for lightweight structures of the roof in sports hall Czyzyna in Cracow.
PublicationThe main aim of this analysis is to characterize numerical simulations connected with modeling dynamic influence of wind on the lightweight structures of the roof in sports hall – “Czyżyna”. This hall is built in Cracow. The article also involves the proposals of the solutions connected with dynamic influence of the wind – Davenport’s method has been used. These proposals have not been taken into consideration at the detailed engineering...
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Modal Analysis of a Steel Radial Gate Exposed to Different Water Levels
PublicationWith the increase in water retention needs and planned river regulation, it might be important to investigate the dynamic resistance of vulnerable elements of hydroelectric power plants, including steel water locks. The most frequent dynamic loads affecting hydroengineering structures in Poland include vibrations caused by heavy road and railway traffic, piling works and mining tremors. More destructive dynamic loads, including...
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Sensitivity analysis of critical forces of trusses with side bracing
PublicationThe present research is devoted to the study of out-of-plane buckling of trusses with elastic side bracing. Inthis paper, a sensitivity analysis of critical buckling loads of a truss due to bracing stiffness is carried out. A method based on the sensitivity analysis for the determination of the threshold bracing stiffness conditionfor full bracing of a truss is proposed. The influence lines of the unit change of the bracing stiffness...
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Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis
PublicationOur analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress-strain...
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Investigation of the Aerodynamics of an Innovative Vertical-Axis Wind Turbine
PublicationThe paper presents the results of an experimental investigation and a three dimensional numerical analysis of the transient aerodynamic phenomena occurring in the innovative modification of classic Savonius wind turbine. An attempt to explain the increased efficiency of the innovative design a comparison with the traditional solution is undertaken. A vorticity measure based on the integral of the velocity gradient tensor second...
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ANALYSIS OF WORKING CONDITIONS OF BEARINGS NO.1 & NO.2 OF TURBINE 13K200 AND DESIGN DEVELOPMENT OF NEW BEARINGS FOR THE TURBINE AFTER RETROFITTING
PublicationThe main goal of the work consisted of preparing an analysis of working conditions of bearings No.1 and No.2 in the existing turbine 13K200, as well as designing geometries of new bearings which would allow for their proper functioning in the turbine following its retrofitting (work under higher load).
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Polynomial description of dynamic impedance spectrogram—introduction to a new impedance analysis method
PublicationThis paper presents a polynomial description of spectrograms obtained using Dynamic Electrochemical Impedance Spectroscopy. A method to fit the polynomial degree correctly is discussed. A simple electrical system of a diode connected in parallel with a capacitor was used for testing. Dynamic impedance measurements during potentiodynamic polarization were conducted. This paper presents an alternative analysis method that allows...
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DESIGN ANALYSIS OF HYBRID GAS TURBINE - FUEL CELL POWER PLANT IN STATIONARY AND MARINE APPLICATIONS
PublicationThe paper concerns design analysis of a hybrid gas turbine power plant with a fuel cell (stack). The aim of this work was to find the most favorable variant of the medium capacity (approximately 50 MW) hybrid system. In the article, computational analysis of two variants of such a system was carried out. The analysis let to calculate capacity, efficiency of both variants and other parameters like flu gas temperature. The paper...
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Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
PublicationCoaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating...
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Numerical modal analysis of a vertical rising steel water gate
PublicationVertical rising steel water gates are very common not only in Poland and Germany but also in other countries of the world. Their popularity is mainly attributed to their simplicity of construction, which makes their production process cheaper and faster when compared to other solutions. The aim of this paper is to conduct a numerical modal analysis to examine the eigenvalues and eigenmodes of a vertical rising steel gate. Two cases...
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The use of plate springs for preloading of a system of tapered roller bearings of a wind turbine gearbox
PublicationThe use of preloaded tapered roller bearings in wind turbine drive systems allows a transfer of load in the case of high variations of axial forces. The examined bearing system, a modification of a current design, consists of a pair of different sized bearings. Previous study showed the high sensitivity of tapered roller bearings on the existing radial interference. Dimensional tolerances used in the original design do not allow...
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An Innovative Floating System with a Savonius Rotor as a Horizontal-Axis Wind Turbine
PublicationIn this project, an innovative wind turbine was designed for a floating plant. A large Savonius rotor was replaced with a double-rotor wind turbine implemented as a horizontal-axis turbine. This double rotor was positioned on the tip of a thrust plate and fixed to the deck of a catamaran. Simple 2D numerical simulations were performed to confirm the effectiveness of the concept. An analysis of the floating system configuration...
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Differential analysis of dynamic immittance spectra
PublicationThis work presents a new approach to the analysis of immittance spectrograms of systems characterised by non-stationarity. The possibility of linking the evolution of the immittance response with changes in the parameters describing the system is achieved by introducing a spectrum in differential form. By using the above procedure, it becomes possible to separate elements with a dependence (or lack thereof) from an independent...
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Kinetic analysis of the stage for a high speed steam turbine
PublicationThis article analyzes possibilites of resonances within a control stage for a high speed steam turbine. This stage hase been based on assembling of a single blade to a rotating disk and increasing of rigidity of the system by using of a bandage. In the analysis will be nd a possiblity of resonance frequency, and mistuning by showing safety working ranges. The calculations have bean used the3D modal and harmonic analysis by the...
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Modal analysis of temporary steel grandstand equipped with different bracing systems
PublicationThe aim of this paper is to present the results of numerical analysis focused on temporary steel scaffolding grandstand. The investigation has been devoted to modal analysis where modes of free vibrations and corresponding natural frequencies have been estimated and compared. The structure was equipped with different types of stiffener members. One on them is a typical tubular stiffener, while the second one is spe-cially designed...
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Dynamic analysis of lightweight structure of the Viaduct Millau in France subjected to the wind fluctuations described by Karman’s and Davenport’s spectrum
PublicationThe article presents numerical simulations for wind impact modelling on the Millau Viaduct structure in France performed with two independent spectrum generation methods. The viaduct's construction in affected by strong forces, as it is situated in the Tarn river's valley. Thus, the loading coming from the wind cannot be modelled, the way it is in case of simple structures as static loading, but as a loading in a form of a spectrum...
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Wind resource assessment and energy yield prediction for the small wind turbine on the Szubieniczne Hill
PublicationThe goal of this study is to preliminary assess the wind resources on the Szubieniczne Hill in order to predict the annual energy production for planned small wind turbine. The analyzed site is located close to the Gdańsk University of Technology campus, in complex urban environment additionally surrendered by forested hills. The assessment is based on Computational Fluid Dynamics simulations which allow to evaluate the wind energy potential...
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Bisquare robust polynomial fitting method for dimple distortion minimization in surface quality analysis
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MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS
PublicationThe aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase...
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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...
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Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine
PublicationA small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performancehas been investigated numerically. Results of a parametric study have been presented in this paper.As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected.Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT).Simulations were carried out with Computational Fluids...
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Damage detection in turbine wind blades by vibration based methods
PublicationThe paper describes results of numerical simulation for damage localization in the composite coat of a wind turbine blade usingmodal parameters and a modern damage detection method (wavelet transform).
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Simulation of static response of thin walled bars with changed design parameters by means of second order sensitivity analysis.
PublicationZa pomocą analizy wrażliwości drugiego rzędu wyznaczono przybliżone wartości sił wewnętrznych i przemieszczeń pręta cienkościennego dla zmieniających się parametrów projektowych. W przykładzie numerycznym wyznaczono pierwszą i drugą wariację bimomentu w funkcji grubości półek skręcanego dwuteownika. Zbadano dokładność rozwiązania uzyskanego za pomocą analizy wrażliwości z rozwiązaniem ścisłym.
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Opitmalising Human Development Index with sensitivity analysis
PublicationResearch background: Composite indicators are commonly used not only to measure economic development, the standard of livin g, competitiveness, fairness, effectiveness but are also willingly implemented in to many different fields. How- ever, it seems that in most cases the variable weig hting procedure is avoided or erroneous since in most cases so-called “wights by belief” are...
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Heave Plates with Holes for Floating Offshore Wind Turbines
PublicationThe paper presents an innovative solution which is heave plates with holes. The long-known heave plates are designed to damp the heave motion of platforms. They are most often used for Spar platforms. The growing interest in this type of platform as supporting structures for offshore wind turbines makes it necessary to look for new solutions. Based on the available literature and the authors’ own research, it was concluded that...
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Real-time hybrid model of a wind turbine with doubly fed induction generator
PublicationIn recent years renewable sources have been dominating power system. The share of wind power in energy production increases year by year, which meets the need to protect the environment. Possibility of conducting, not only computer simulation, but also laboratory studies of wind turbine operation and impact on the power system and other power devices in laboratory conditions would be very useful. This article presents a method...
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Verification of algorithms determining wave loads on support structure of wind turbine
PublicationThe offshore wind turbines require determination of wave loads on their support structure. This structure is fixed and, therefore, this problem is reduced to solving only the diffraction problem, which is determined by Laplace equation and conditions on the following boundaries: on the support structure, on the sea free surface and on its bottom, and at infinity on free surface. The linear problem was applied to determine the wave...
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Life Cycle Analysis of Ecological Impacts of an Offshore and a Land-Based Wind Power Plant
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Comparison Analysis of Blade Life Cycles of Land-Based and Offshore Wind Power Plants
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Design of horizontal axis wind and water turbines
PublicationThe basic hydrodynamic principles of horizontal axis turbines are presented. Computational methods based on vortex theory for design of such turbines and for calculation of their hydro or aerodynamic characteristics are described in detail. These methods are applicable both to wind and water turbines. The influence of detailed turbine geometry on its characteristics is presented. Several practical computational examples of different...
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A Diagnostic Method Based on Deflection Analysis for Monitoring Post-elastic Response of Beams
PublicationA non-destructive diagnostic method based on deflection analysis for monitoring the post-elastic response of beams was developed, and a diagnostic indicator was proposed. The indicator was defined as the second moment of the normalised curvature function about the mid-span, where the curvature was computed from the normalised deflection function. Elastic reference values of the indicator were computed for simply supported beams...
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Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems
PublicationThis paper presents an overview of the DC link development and evolution dedicated to HVDC structure for connecting offshore wind power plants to onshore power systems. The growing demand for the green energy has forced investors in power industry to look for resources further out at sea. Hence, the development of power electronics and industrial engineering has enabled offshore wind farms to be situated further from the shore...
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Modal analysis of a fish-belly flap type of steel water gate
PublicationABSTRACT: The results of a modal analysis of the fish-belly flap type of steel water gate are presented in the paper. The analysis was conducted for a detailed numerical model of the structure using four-node quadrilateral shell elements. The study was focused on the examination of the influence of positioning of the flap gate and hydrostatic pressure of water on the eigenvalues and eigenmodes of the structure. The results of the study...
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MULTI-CRITERIA COMPARATIVE ANALYSIS OF THE USE OF SUBTRACTIVE AND ADDITIVE TECHNOLOGIES IN THE MANUFACTURING OF OFFSHORE MACHINERY COMPONENTS
PublicationThe dynamic development of additive manufacturing technologies, especially over the last few years, has increased the range of possible industrial applications of 3D printed elements. This is a consequence of the distinct advantages of additive techniques, which include the possibility of improving the mechanical strength of products and shortening lead times. Offshore industry is one of these promising areas for the application...
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Sensitivity analysis of flexural and torsional buckling loads of laminated columns
PublicationThe paper concerns first order sensitivity analysis of flexural and torsional bucklin g loads of axiallycompressed thin-walled columns with bisymmetric or axisymmetric cross-section made of unidirectional fibre-reinforcedlaminate. The first variation of critical loads versus some variations of the column material properties and cross-sectionaldimensions is derived. Numerical examples dealing with simply supported I-columns are...
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Multi-Criterial Design of Antennas with Tolerance Analysis Using Response-Feature Predictors
PublicationImperfect manufacturing is one of the factors affecting the performance of antenna systems. It is particularly important when design specifications are strict and leave a minimum leeway for a degradation caused by geometry or material parameter deviations from their nominal values. At the same time, conventional antenna design procedures routinely neglect to take the fabrication tolerances into account, which is mainly a result...
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Implementation of multicriteria decision analysis in design of experiment for dispersive liquid-liquid microextraction optimization for chlorophenols determination
PublicationA novel and efficient approach to optimization of extraction step prior the chromatographic determination of nine chlorinated phenols is described. It is based on the combination of design of experiments and multicriteria decision analysis. Such an approach is used to optimize dispersive liquid-liquid microextraction procedure for the determination of 9 chlorophenols in water samples. Three parameters are optimized – sample volume,...
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Improved Efficacy Behavioral Modeling of Microwave Circuits through Dimensionality Reduction and Fast Global Sensitivity Analysis
PublicationBehavioral models have garnered significant interest in the realm of high-frequency electronics. Their primary function is to substitute costly computational tools, notably electromagnetic (EM) analysis, for repetitive evaluations of the structure under consideration. These evaluations are often necessary for tasks like parameter tuning, statistical analysis, or multi-criterial design. However, constructing reliable surrogate models...
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Modal Analysis of Planar Elliptical Resonator Deposited on Unshielded Dielectric Slab
PublicationModal analysis of isolated open planar elliptical patch placed on dielectric slab is presented in the paper. It applies concept of Illuminating Modes which is formulated for the case of two-side opened structure. The current on patch is expanded in basis functions in form of Mathieu radial and angular functions. The spectrum of excited modes for exemplary planar resonators is presented and discussed using the concept of power of...