30 research outputs found

    Wind tunnel tests of wind action on an aquaporine model exhibit

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    In the paper, wind tunnel tests of wind action on an aquaporine model exhibit performed in a boundary layer wind tunnel of the Wind Engineery Laboratury at the Cracow University of Technology have been presented. In the experiments, most of the similarity criteria elaborated specially for this purpose have been fulfilled. Moreover, safety assessments of the exhibit with respect to a strong wind action have been done

    Stosunki si艂 i moment贸w si艂 jako kryteria podobie艅stwa dynamicznego r贸偶nych zjawisk wyst臋puj膮cych w in偶ynierii wiatrowej, in偶ynierii 艣niegowej i dynamice p艂yn贸w

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    The work concerns dynamic similarity criteria of various phenomena occur-ring in wind engineering, snow engineering and fl uid dynamics derived from ratios of forces and forces moments affecting these phenomena. Derived and analyzed in part II dynamic similarity criteria, mainly concern the following unsteady problems of periodic, quasi-perio-dic and turbulent character: 1. Vibrations of a solid in a stationary and moving fl uid; 2. Snow particles/fl akes/clusters breaking off the outer layer of the snow deposit; 3. Rotating turbines, propellers or screw propellersPraca dotyczy kryteri贸w podobie艅stwa dynamicznego r贸偶nych zjawisk wyst臋puj膮cych w in偶ynierii wiatrowej, in偶ynierii 艣niegowej i dynamice p艂yn贸w wyprowa-dzonych ze stosunk贸w si艂 i moment贸w si艂 wp艂ywaj膮cych na te zjawiska. Wyprowadzonei analizowane w cz臋艣ci II kryteria podobie艅stwa dynamicznego dotycz膮 g艂贸wnie nast臋puj膮-cych zagadnie艅 nieustalonych o charakterze okresowym, quasi-okresowym i turbulentnym: 1. Drga艅 cia艂a sta艂ego w nieruchomym lub ruchomym p艂ynie; 2. Odrywania si臋 cz膮stek/p艂at-k贸w/klastr贸w 艣niegowych z wierzchniej warstwy z艂o偶a 艣niegu; 3. Wiruj膮cych turbin, 艣migie艂lub 艣rub okr臋towych

    Stosunki si艂 i moment贸w si艂 jako kryteria podobie艅stwa dynamicznego r贸偶nych zjawisk wyst臋puj膮cych w in偶ynierii wiatrowej, in偶ynierii 艣niegowej i dynamice p艂yn贸w

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    The work concerns dynamic similarity criteria of various phenomena occur-ring in wind engineering, snow engineering and fl uid dynamics derived from ratios of forces and forces moments affecting these phenomena. Derived and analyzed in part II dynamic similarity criteria, mainly concern the following unsteady problems of periodic, quasi-perio-dic and turbulent character: 1. Vibrations of a solid in a stationary and moving fl uid; 2. Snow particles/fl akes/clusters breaking off the outer layer of the snow deposit; 3. Rotating turbines, propellers or screw propellersPraca dotyczy kryteri贸w podobie艅stwa dynamicznego r贸偶nych zjawisk wyst臋puj膮cych w in偶ynierii wiatrowej, in偶ynierii 艣niegowej i dynamice p艂yn贸w wyprowa-dzonych ze stosunk贸w si艂 i moment贸w si艂 wp艂ywaj膮cych na te zjawiska. Wyprowadzonei analizowane w cz臋艣ci II kryteria podobie艅stwa dynamicznego dotycz膮 g艂贸wnie nast臋puj膮-cych zagadnie艅 nieustalonych o charakterze okresowym, quasi-okresowym i turbulentnym: 1. Drga艅 cia艂a sta艂ego w nieruchomym lub ruchomym p艂ynie; 2. Odrywania si臋 cz膮stek/p艂at-k贸w/klastr贸w 艣niegowych z wierzchniej warstwy z艂o偶a 艣niegu; 3. Wiruj膮cych turbin, 艣migie艂lub 艣rub okr臋towych

    Comparison of determination methods of vibration鈥檚 damping coefficients for complex structures

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    The purpose of this paper is to present methods of vibrations damping coefficient determination. The methods, such as collocation method, two energetic methods and half-power bandwidth method concern composite structures. The verification of methods has been taken into account in this work. Two real compound models and two numerical models have been created. Time series of vibrations of these models have been measured and calculated. The comparison of four methods has been made on the basis of obtained results.The purpose of this paper is to present methods of vibrations damping coefficient determination. The methods, such as collocation method, two energetic methods and half-power bandwidth method concern composite structures. The verification of methods has been taken into account in this work. Two real compound models and two numerical models have been created. Time series of vibrations of these models have been measured and calculated. The comparison of four methods has been made on the basis of obtained results

    Badania modelowe w tunelu aerodynamicznym wirnik贸w wiatrowych typu Magnusa o poziomej osi obrotu

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    The paper presents results of wind tunnel tests of horizontal axis wind  rotors of Magnus type. Firstly, measurements of aerodynamic side (lift) force and aerodynamic drag on rotating cylinder attached to horizontal aerodynamic balance were performed. Secondly, the model of single-blade rotor with counterbalance was tested.Praca przedstawia wyniki bada艅 eksperymentalnych w tunelu aerodynamicznym wirnik贸w typu Magnusa o poziomej osi obrotu. Najpierw przeprowadzono pomiary aerodynamicznej si艂y bocznej (no艣nej) oraz oporu aerodynamicznego na wiruj膮cym walcu do艂膮czonym do wagi aerodynamicznej. Nast臋pnie wykonano badania wirnika jedno艂opatowego z przeciwwag膮.&nbsp

    Badania modeli aeroelastycznych przewod贸w linii wysokiego napi臋cia dla r贸偶nych przypadk贸w ich o艣nie偶enia i oblodzenia

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    In the first part of this paper, similarity criteria were elaborated for investiga-tions of aeroelastic sectional models of high voltage line wires. These criteria consider wire vibrations caused by aeroelastic phenomena: vortex excitation, wake galloping and interfer-ence between the wires causing vibration in aerodynamic trace of other wires. Second part of the paper describes the tests conducted in Wind Engineering Laboratory of Cracow Univer-sity of Technology. The subject of this set of tests was identifi cation of aeroelastic vibrations caused by aeroelastic interference of wires, mainly determination of critical velocity of wires galloping and wake galloping for selected cases of snow and ice covers on the wires.W pierwszej cz臋艣ci pracy wyprowadzono kryteria podobie艅stwa dla bada艅modeli aeroelastycznych odwzorowuj膮cych przewody linii wysokiego napi臋cia. Kryteria te uwzgl臋dniaj膮 drgania przewod贸w przy wyst臋powaniu zjawisk aeroelastycznych: wzbudzenia wirowego, galopowania oraz interferencji i drgania w 艣ladzie aerodynamicznym innych prze-wod贸w. Druga cz臋艣膰 pracy przedstawia przeprowadzone w Laboratorium In偶ynierii Wiatrowej Politechniki Krakowskiej badania modeli aeroelastycznych wi膮zki trzech przewod贸w linii wy-sokiego napi臋cia. Badania te mia艂y na celu identyfi kacj臋 drga艅 aeroelastycznych spowodowa-nych wzajemn膮 interferencj膮 przewod贸w, a w szczeg贸lno艣ci wyznaczenie pr臋dko艣ci krytycznej dla galopowania przewod贸w dla wybranych przypadk贸w o艣nie偶enia i oblodzenia przewod贸w

    Badania modelowe w tunelu aerodynamicznym prawid艂owo艣ci dzia艂ania ci膮g贸w w przewodach kominowych w budynku w zabudowie zwartej

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    The paper deals with model investigations on wind pressure distributions on walls and roof of a tenement house in compact development of Cracow centre. The tests were performed in a boundary layer wind tunnel at the Cracow University of Technology for eight wind directions. Two situations were tested: 1. Before realization of a superstructure  on the adjacent building; 2. After realization of the superstructure. Investigations results were used for evaluation of correct work of chimneys and ventilations draughts of the building.Praca dotyczy bada艅 modelowych, na podstawie kt贸rej wyznaczono rozk艂ady ci艣nie艅 wiatru na 艣cianach i dachu kamienicy w zabudowie zwartej w centrum Krakowa. Badania przeprowadzono w tunelu aerodynamicznym Politechniki Krakowskiej dla o艣miu kierunk贸w natarcia wiatru. Rozwa偶ono dwie sytuacje pomiarowe: 1. Przed wykonaniem nadbudowy na s膮siednim budynku; 2. Po wykonaniu tej nadbudowy. Wyniki bada艅 pos艂u偶y艂y do oceny prawid艂owo艣ci dzia艂ania ci膮g贸w kominowych i wentylacyjnych  przedmiotowego budynku.&nbsp

    Analysis of aerodynamic interference between a high-rise building and its immediate city surroundings

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    This paper summarizes results of wind tunnel tests of a high-rise building placed in Warsaw city centre. Aerodynamic laboratory studies were accomplished in a boundary layer wind tunnel. The main objective of the research was to determine the distribution of the mean wind pressure coefficient over the building鈥檚 external surfaces as affected by the aerodynamic interference between the structure and its immediate city surroundings. Interference coefficients of wind pressure and global wind forces acting upon the surfaces of the building walls and roof were calculated. The aerodynamic studies showed a significant influence of objects located nearby on the wind load that the high-rise building structure surfaces are subjected to

    An acoustic study of the auditorium hall to be located in the proposed building of the Applied Acoustics Laboratory of Cracow University of Technology

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    This paper presents an acoustic study of the auditorium hall located in the proposed building of the Applied Acoustics Laboratory of Cracow University of Technology. The study shows a comparative analysis of two solutions to the acoustic adaptation of this room. The aim of this study was to demonstrate that with a given room shape and finishing materials, it is possible to optimize the sound quality of the interior through changes to some architectural details, for example, by the adequate formation and arrangement of finishing elements

    Wind tunnel tests of acoustic panels

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    The paper summarizes the wind tunnel tests of original acoustic panels located on the block buildings roofs near edge of building roof and walls. Performed investigations had two main goals: 1. Verification of resistance of the panels at their connecting members at high air flow velocities; 2. Determination the set of aerodynamic force coefficients, obtained from measured wind pressure distribution on the fa莽ade panel surfaces in two opposite wind directions, was the main aim of the work
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