Wyniki wyszukiwania - Biblioteka Nauki

1

Towards the Design of Low Noise Level Wind Turbines

100%

Chaja P. , Koronowicz T.

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2009

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tom Vol. 13, No 4

393-401

EN

According to the authors’ hypothesis generation of high intensity noise is caused by generation of vorticity structures inducing velocities that can be locally higher than the velocity of sound. The localization and magnitude of vorticity concentration can be precisely defined on the basis of a double layer vortex model. Knowing the localization and mechanism of generation of significantly high induced velocities, turbine blades can be shaped in such a way so as to decrease the concentration of vorticity in these zones. According to the hypothesis described in this paper, a modification of turbine blades at the design stage results in their quieter operation for higher loads and wind velocities. The authors base their hypothesis on the experience from design works concerning low noise ship propellers. The following paper focuses on these tasks.

2

Stanowisko do badania wirników turbin wiatrowych o poziomej osi obrotu

100%

Garbala K. , Mogielnicki K.

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2009

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tom T. 14, nr 4

32-37

PL

W pracy zaprezentowano stanowisko do badania parametrów i wskaźników pracy wirników turbin wiatrowych o poziomej osi obrotu. Przedstawiono budowę i specyfikację techniczną oraz omówiono możliwości badawcze tego stanowiska. Zamieszczono przykładowe badania trójłopatowego wirnika typu Clark-Y. Wirnik przebadano pod kątem parametrów i wskaźników pracy w funkcji zmiennego kąta natarcia łopat. Celem eksperymentu była optymalizacja danych nastawczych urządzenia dla efektywnego wykorzystania energii wiatru w obszarze badanej lokalizacji.

EN

This paper presents an experimental setup for research of parameters and work indicators of horizontal axis wind turbine. Moreover, it shows structure, specification and setup's investigative possibilities. There are presented samples of researches for three - blades Clark-Y rotor. The rotor has been investigated due to check parameters and indicators in function of variable angle of attack. The aim of this investigation was to optimize rotor's adjusting data for effective wind energy use in examination area.

3

Annoyance Related to Wind Turbine Noise

100%

Pawlaczyk-Łuszczyńska M. , Dudarewicz A. , Zaborowski K. , Zamojska-Daniszewska M. , Waszkowska M.

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nr 1

4

Nowoczesne przekształtniki energoelektroniczne przeznaczone do odnawialnych źródeł energii

100%

Tarczewski T.

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2012

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tom R. 80, nr 9

9-11

PL

Przedstawiono systemy generatorowe we współczesnych turbinach wiatrowych pracujących ze stałą i zmienną prędkością obrotową.

EN

The paper presents generating systems in contemporary wind turbines operated with constant and variable speed of rotation.

5

Comparison of Amplitude-Based and Phase-Based Methods for Speed Tracking in Application to Wind Turbines

88%

Urbanek J. , Barszcz T. , Sawalhi N. , Randall R.

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6

Prediction of the three-dimensional separation on a rotating blade

88%

Dumitrescu H. , Cardos V.

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2007

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tom Vol. 12, no 4

941-950

EN

Blade rotation routinely and significantly augments aerodynam c forces during zero yaw horizontal axis wind turbine operation. To understand better the flow physics underlying this phenomenon, three-dimensional and rotational viscous effects on wind turbine blades are investigated by means of a 3-D boundary-Iayer model. The governing equations of the model are derived from 3-D primitive variable boundary-Iayer equations written in cylindrical coordinates in the rotating fratne of reference. The latter are integrated along the peripheral direction with the radial distance as parameter for a particular external flow. The skin friction coefficient is used to identify boundary layer separation and shear layer reattachment locations. Separation and reattachment kinematics shows at inboard locations that while the separation point location is not realIy atTected and remains near the leading edge, the reattachment point advances forward rapidly on the blade chord from the trailing edge as radial distance decreases. It is concluded that the rotational augmentation is linked to specific separation and reattachment state strictly determined by the Coriolis forces.

7

Analysis of inboard flow around the wind turbine blades

88%

Dumitrescu H. , Cardos V.

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2011

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tom Vol. 16, no 2

345-358

EN

The complex flow in the rotor root area is analyzed by means of the boundary layer approach. The approach involves a radial angular velocity (Ekman) boundary-layer on the rotor disk rotating with an angular velocity smaller than that of the fluid, and the circumferential velocity boundary-layer developing on blades. The first explains the smaller adverse pressure gradient at the leading-edge of blades by a vortex-induced sucking effect, and the other shows the contribution of Coriolis force to the closed separation behavior on the suction side of the inboard blade sections, that explains the stall-delay phenomenon. Three-dimensional incompressible steady momentum integral boundary layer equations are used to analyze the leading-edge separation bubble on a rotating blade, including the effect of enhanced rotation at strong winds. The stall-delay phenomenon is described as a three contribution process: vortex-induced sucking effect by an Ekman layer type boundary-layer followed by Coriolis force, which acts in the chordwise direction as a favorable pressure gradient, and centrifugal forces producing a spanwise pumping effect. It appears that the first two contributions play the primary role for the rise of the inboard stall-delay and the centrifugal pumping effect is much less important than generally was supposed before.

8

On the inboard stall delay due to rotation

75%

Dumitrescu H. , Cardos V.

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2008

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tom Vol. 13, no 2

359-372

EN

This paper investigates the boundary-layer characteristics of a wind turbine blade of small chord length. The three-dimensional form of momentum integral equations is derived and used to predict the boundary-layer growth and limiting streamline angles on the blade surface for both attached and separating flow. The chordwise skin friction coefficient is used to identify boundary layer separation and shear layer reattachment locations. The nature of flow near the axis of rotation is discussed and the physical mechanism associated with 3-D and rotational effects is identified. A semi-empirical correction law for the lift coefficient based on 2-D airfoil data is established. Comparing calculated and measured lift curves of a stall controlled wind turbine, it is shown that the proposed correction law may improve significantly the accuracy of the predictions.

9

Sterowanie wartości rezystancji dodatkowej w obwodzie wirnika generatora asynchronicznego

75%

Błasiński W.

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2012

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tom nr 12

787-790

PL

Rozważono układ sterowania wartością rezystancji dodatkowej w obwodzie wirnika asynchronicznego generatora pierścieniowego stosowanego w turbinach wiatrowych. W układzie laboratoryjnym turbinę wiatrową zastępuje sterowany napęd z silnikiem prądu stałego. Porównanie wyników układu laboratoryjnego i modelu symulacyjnego układu sterowania będą podstawą do realizacji algorytmów sterowania ekstremalnego. W tym przypadku konieczna będzie znajomość charakterystyk turbiny wiatrowej.

EN

Considered is a control system of an extra resistance value in a rotor circuit of an asynchronous ring generator used in wind turbines. In a laboratory-built system the wind turbine is replaced by a controlled drive equipped with a DC motor. A comparison of the results obtained from the laboratory system and from the simulation control system model will be the basis for realization of extremal control algorithms. In this case, a knowledge of a wind turbine characteristcs will be needed.

10

Zastosowanie materiałów kompozytowych w turbinach wiatrowych o pionowej osi obrotu

75%

Garbala K. , Patejuk A.

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2006

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tom nr 1-2

75-77

11

New Isolated Interface Converter for PMSG based Variable Speed Wind Turbines

63%

Vinnikov D. , Bisenieks L. , Galkin I.

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2012

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tom R. 88, nr 1a

75-80

EN

This paper presents a new converter topology for interfacing a permanent magnet synchronous generator based variable speed wind turbine with a residential power network. The theory of wind energy conversion is analyzed first. Then an example of wind velocity distribution and normalized energy yield is discussed in order to formulate requirements for choosing a power converter. A new topology of an interfacing converter is analyzed and simulation results of a lossless model are presented. Simulation and experimental results of the proposed converter prove that its utilization in wind power applications is beneficial.

PL

W artykule przedstawiono nową topologię przekształtnika do sprzęgania instalacji domowych z turbiną wiatrową o zmiennej prędkości zbudowaną na bazie generatora synchronicznego z magnesami trwałymi. W pierwszej kolejności przedstawiona została teoria przetwarzania energii wiatru. Następnie w celu sformułowania wymagań dotyczących wyboru mocy przekształtnika omówiono przykład rozkładu prędkości wiatru i znormalizowaną wydajność energetyczną. Nowa topologia przekształtnika sprzęgającego jest analizowana i symulowana przy założeniu modeli bezstratnych. Wyniki badań symulacyjnych i eksperymentalnych proponowanego przekształtnika udowodniły, że jego zastosowanie w elektrowniach wiatrowych jest korzystne.