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Computational Fluid Dynamics Studies of a Vertical Axis Wind Turbine with a Variable Swept Area

Pędzisz Idzi, Magryta Paweł, Pietrykowski Konrad

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

333--348

EN

The article presents the results of the CFD (Computational Fluid Dynamics) research on a vertical axis wind turbine with a variable swept area. The tested turbine has four sets of blades, each of which consists of two moving parts. By changing the angle between these parts, it is possible to change the swept area of the turbine wheel to adjust the characteristics of the turbine to the current wind speed. In the case of strong wind, it is possible to fold blades to protect the rotor against damage. The 3D-CFD model was tested using the ANSYS Fluent software. The four rotors differing in the blade angle were analyzed. The tests were carried out for different wind speeds. The results are presented as pressure and velocity distributions as well as streamlines around the rotor. In addition, the waveforms of the torque acting on a single blade and on the entire rotor are shown. The average rotor torque was also calculated. These findings enabled us to create the characteristics of the power factor for different rotational speeds of the rotor. The results show that the adjustment of the swept area makes the z-turbine have a flexible operating range.

2

Analiza techniczno-ekonomiczna, porównawcza źródeł ciepła bazujących na odnawialnych źródłach energii ze źródłem zasilanym gazem ziemnym dla domu jednorodzinnego

Grudzińska Kalina

Gaz, Woda i Technika Sanitarna

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2022

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Nr 3

29--38

PL

Artykuł przedstawia porównanie źródła ciepła bazującego na paliwie kopalnym do urządzeń zasilanych przy pomocy odnawialnych źródeł energii, które są stosowane dla małych kubatur. Analiza została opracowana na przykładzie domu jednorodzinnego znajdującego się w Warszawie. Zakres pracy obejmuje porównanie wydajności i kosztów eksploatacji kotła zasilanego gazem ziemnym do dobranych pomp ciepła, instalacji fotowoltaicznej oraz turbiny wiatrowej o pionowej osi obrotu. Artykuł powstał na podstawie sporządzonej przez Autora pracy inżynierskiej [1].

EN

The article presents the comparison between heat source based on fossil fuels and devices powered by renewable energy sources, which are used in small building volumes. The analysis was carried out on the example of the detached house located in Warsaw. The scope of the study covers comparison of the efficiency and operating costs of gas boiler and selected heat pumps, photovoltaic installation and vertical axis wind turbine.

3

Location-optimized aerodynamic rotor design studies and development of small wind turbines

Lehser-Pfeffermann Daniel, Hamman Alexander, Rückert Frank Ulrich

Archives of Thermodynamics

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2022

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Vol. 43, no 1

3--19

EN

Local wind conditions can vary strongly depending on the landmark and vegetation, as well as on the skyline of the buildings in an urban surrounding. Weather, season and time of day influence the yield of electric power. In order to promote the use of small wind turbines as an alternative to photovoltaic power generation, design optimization for location-optimized small wind turbines was carried out. In this work, we want to concentrate on vertical axis wind turbines. Experimental studies, as well as numerical simulations, have been conducted. On the one hand, bionically optimized core structures will be integrated and implemented in the hybrid material of the turbine blades. Several optimization attempts have been examined for single blades. Detailed simulative investigations with large eddy simulations improve the aerodynamic behaviour of the new rotor design. Finally, based on the results of the studies and investigations, a new rotor will be manufactured and tested experimentally in the wind tunnel. A comparison with the reference system from the first part of the paper shows the improvements and effectiveness of the measures and processes investigated.

4

A vertical-axis rotor as the adjusting system of a horizontal axis wind turbine

Augustyn Marcin

Technical Transactions

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2020

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Vol. 117, iss. 1

art. no. e2020009

EN

The proposed self-adjusting mechanism consists of a carousel rotor with a vertical axis consisting of two kinematically connected flat blades. The torque of this rotor can change the position of the directing unit and additionally the position of the main propeller in order to direct the wind stream or save the main rotor when the wind is too strong. The theory, principles of operation, and the properties of the self-adjusting system were illustrated by formulas and graphs. Based on research conducted in a boundary layer wind tunnel, the values of the aerodynamic coefficients of the flat blades were determined, and then the power and propeller torque of the rotor were found as a function of the angle of wind attack. Acomputational procedure provides kinematical and force relations as well as the resulting torque diagrams of the rotor. An example of the use and the design structure of a self adjusting unit in the case of a horizontal axis wind turbine is presented.

PL

W artykule zaprezentowano nowatorskie rozwiązanie zespołu samonaprowadzania na kierunek wiatru turbiny wiatrowej o poziomej osi obrotu, składające się z dwułopatowego, karuzelowego wirnika o pionowej osi obrotu i dwupozycyjnego mechanizmu nastawczego. Na podstawie przeprowadzonych badań w tunelu aerodynamicznym wyznaczono wartości współczynników aerodynamicznych łopaty płaskiej wirnika dwułopatowego turbiny naprowadzającej, a ich wartości zobrazowano na wykresach. Przedstawiono procedurę obliczeniową mocy oraz momentu napędowego wirnika zespołu samonaprowadzania w zależności od kąta działania wiatru. Wyniki obliczeń pokazano na wykresach. Zaprezentowano budowę i zasadę działania turbiny naprowadzającej, a także propozycję wykorzystania jej jako zespołu samonaprowadzania na kierunek wiatru z jednoczesnym zabezpieczeniem wirnika głównego HAWT przed nadmiernymi obrotami przy silnym wietrze.

5

Analiza wydajności energetycznej dwuwirnikowej turbiny wiatrowej o pionowej osi obrotu

Bugała Artur, Bednarek Karol

Przegląd Elektrotechniczny

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2020

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R. 96, nr 1

206--209

PL

W pracy włączono sie w powszechnie prowadzone rozważania dotyczące ekologicznych aspektów wytwarzania energii elektrycznej. Bardziej szczegółowo zajęto sie wydajnością energetyczną turbin wiatrowych, przy czym skupiono się głównie na turbinach wiatrowych małej mocy o pionowej osi obrotu. Analizy przeprowadzono dla lokalizacji systemu w mieście Poznań. W końcowej części porównano własności użytkowe turbin o pionowej osi obrotu (VAWT) z powszechnie stosowanymi turbinami o poziomej osi obrotu (HAWT).

EN

The study joins the commonly conducted considerations regarding ecological aspects of electricity generation. The energy efficiency of wind turbines was analyzed in details, with a focus on low power wind turbines with a vertical axis of rotation. The analyzes were carried out for the system located in the city of Poznań. Finally, the performance characteristics of vertical rotation axis wind turbines (VAWT) were compared with commonly used horizontal axis wind turbines (HAWT).

6

System zdalnego monitoringu parametrów pracy siłowni wiatrowej o pionowej osi obrotu

Kostro Grzegorz, Kutt Filip, Michna Michał, Ryndzionek Roland, Sienkiewicz Łukasz, Ronkowski Mieczysław

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

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2019

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Nr 64

25--28

PL

W artykule przedstawiono układ do zdalnego monitorowania parametrów pracy elektrowni wiatrowej o pionowej osi obrotu. Do budowy systemu wykorzystano mikrokomputer klasy Raspberry PI 3 z zainstalowanym systemem operacyjnym Raspbian oraz kartę pomiarową MicroDAQ E2000. Opracowany system umożliwia monitorowanie mocy na wyjściu generatora, momentu na wale turbiny, prędkości obrotowej turbiny oraz prędkości wiatru. Wartości monitorowanych parametrów zapisywane są w pamięci karty pomiarowej. Dzięki zastosowaniu mikrokomputera możliwe było podłączenie komputera zewnętrznego do systemu i przesyłanie zapisanych danych oraz monitorowanie ich wartości online.

EN

The article presents a system for remote monitoring of working parameters of a wind turbine with vertical axis. The system was built using a Raspberry PI 3 microcomputer with the Raspbian operating system and a MicroDAQ E2000 measuring card. The developed system enables monitoring the power output of the generator, torque on the turbine shaft, turbine speed and wind speed. The values of the monitored parameters are saved in the memory of the measuring card. Due to the use of a microcomputer, it is possible to connect an external computer to the system and send saved data and monitor their value online.

7

Numerical modeling of vertical axis wind turbine with air guides

Kołodziejczyk Krzysztof, Ptak Radosław, Korman Jakub

New Trends in Production Engineering

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2019

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Vol. 2, Iss. 1

589--595

EN

Currently, obtaining energy from renewable sources, as never before, it has become one of the most important areas, but at the same time challenges in human activities. This is the effect of many factors simultaneously, including because of the media trumpeted the greenhouse effect, the necessity of reducing CO2 emissions, shrinking natural resources, and thus the desire to protect their welfare including conservation (including natural resources) for future generations. The paper presents the results of preliminary numerical analyzes of work for vertical axis wind turbines equipped with air guides. The carried out analyzes indicate the potential possibility of using this type of construction in practice. The obtained power factor value is higher than in classic wind turbines with a vertical axis. The conducted analyzes also indicate the possibility of optimizing the proposed constructional solution in order to increase efficiency of obtaining energy from the wind.

8

Green energy from a hybrid PV panels and wind turbine farm in Lebanon

Nesser Bassel I., Soliman Mohamed Hassan, Pytel Krzysztof

New Trends in Production Engineering

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2019

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Vol. 2, Iss. 1

541--548

EN

The publication presents the results of analysis of green energy from a hybrid PV panels and wind turbine farm use in Lebanon. Electricity is one of the most critical problems in Lebanon. This publication presents an effective solution to this issue. It deals with the generation of green environment friendly electricity from photovoltaic (PV) panels and wind turbine. The genuine idea consists of placing these panels and turbines at the middle of the coastal highway since it is considered as a free land. The produced energy is fed directly to the off gird after being inverted using appropriate devices. The middle of the highway from Tyre to Sidon is considered to apply this research. The actual design consists of 15222 PV panels placed in pairs on a steel chassis among the entire 27300 m coastal distance, 2 meters wide and 7610 vertical axis wind turbines placed at a distance of 0.9 m away from each pair of PV panels. The total energy produced by the PV system is estimated to 7.4 GWh/y and 3.1 GWh/y at an average wind velocity of 4.04 m/s. In addition to its benefit from a free land, the produced energy is environment friendly since there is no carbon dioxide emission.

9

Investigation and optimization of an untypical vertical axis rotor of a small wind turbine

Kortenstedde Frank, Stief Jan Mathias

Journal of Mechanical and Energy Engineering

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2019

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Vol. 3, No 3

245--258

EN

In this paper, an atypical resistance rotor of a vertical axis small wind energy turbine is to be aerodynamically investigated and later on optimized in a flow simulation. In this report the results obtained from the flow simulations of the single and two rotor setup, as well as the results from the flow simulations of a single blade, are presented. The geometry of the rotor and blades is the base geometry for further optimization. All simulations are performed with one specific tip speed ratio. The base geometry for slat and baffle can be calculated based on experience gained in previous studies. It was found in previous experiments that a rotor with 42% coverage (area that occupies the wings of the total circumference) is always started. Those experiments have also shown that a rotor with 36.5% coverage has a higher power coefficient at low wind speeds, at higher wind speeds, the rotor with 42% coverage has a better power coefficient. Based on those first investigations the optimization of the blade and rotor geometry will be carried out later in this project. Another focal point will be the investigation of the "stacking" of two wind turbines on top of each other in order to obtain a stable torque over the entire circulation and the determination of the optimal distance between two rotors.

10

CFD analysis of the air flow around the blades of the vertical axis wind turbine

Gavgali M. M., Czyż Z., Czarnigowski J.

Journal of Technology and Exploitation in Mechanical Engineering

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2017

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Vol. 3, nr 1

1--7

EN

The paper presents the results of calculations of flow around the vertical axis wind turbine. Three-dimensional calculations were performed using ANSYS Fluent. They were made at steady-state conditions for a wind speed of 3 m/s for 4 angular settings of the three-bladed rotor. The purpose of the calculations was to determine the values of the aerodynamic forces acting on the individual blades and to present the pressure contours on the surface of turbine rotor blades. The calculations were made for 4 rotor angular settings.

PL

W pracy przedstawiono wyniki obliczeń opływu wirnika turbiny wiatrowej o pionowej osi obrotu. Trójwymiarowe obliczenia wykonano za pomocą programu ANSYS Fluent. Obliczenia przeprowadzono w warunkach stacjonarnych dla prędkości wiatru równej 3 m/s dla 4 ustawień kątowych wirnika z trzema łopatami. Celem przeprowadzonych obliczeń było określenie wartości składowych siły aerodynamicznej działającej na poszczególne łopaty oraz przedstawienie konturów ciśnienia na powierzchni łopat wirnika turbiny. Obliczenia przeprowadzono dla 4 ustawień kątowych wirnika.

11

A new tool for topological optimization of a rotor for vertical axis wind turbines

Jakubowski M., Fritzkowski P.

Vibrations in Physical Systems

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2016

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Vol. 27

143--150

EN

A computer program for topological optimization of a rotor for vertical axis wind turbines of various type is presented. The tool is based mainly on two external modules: the GMSH mesh generator and the OpenFOAM CFD toolbox. Interpolation of rotor blades geometry and computational model of the airflow through a turbine are briefly discussed. Moreover, a simple optimization algorithm is described. Exemplary results for a H-type rotor are presented. Finally, potential directions for the software development are indicated.

12

CFD computation of the savonius rotor

Rogowski K., Maroński R.

Journal of Theoretical and Applied Mechanics

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2015

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Vol. 53 nr 1

37--45

EN

In this paper, Computational Fluid Dynamics (CFD) analysis of a two-dimensional two- -bucket Savonius rotor, using ANSYS Fluent solver, is presented. Computational methods of fluid dynamics are used to estimate the aerodynamic forces acting on the rotor, the torque and the power extracted by the Savonius rotor. In addition, an analysis of the results for different turbulence models is performed. Numerical investigations are compared with the experiment of the Sandia National Laboratories.

13

Modelowanie parametrów aerodynamicznych urządzeń energetyki wiatrowej III. Analiza aerodynamiczna rotorów wiatrowych o pionowej osi obrotu

Sorko S. A., Teleszewski T. J.

Symulacja w Badaniach i Rozwoju

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2014

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Vol. 5, nr 2

119--128

PL

Wirniki rotorów wiatrowych (VAWT - Vertical Axis Wind Turbine) są konstruowane jako układy kształtowych lub profilowanych elementów powierzchniowych tworzących palisady wirnikowe o pionowej osi obrotu. W opracowaniu przedstawiono matematyczny opis zagadnienia przepływu przez cząstkowe sekcje wirnika rotora wiatrowego typu Darrieusa o profilowanych łopatach przy użyciu równań całkowych, dyskretyzację równań całkowych (metoda panelowa), algorytm wyznaczania pól prędkości i ciśnienia oraz wyznaczania charakterystyk użytkowych rotorów wiatrowych o pionowej osi obrotu wirnika.

EN

An object of the elaboration is the computational method solution of the flow through rotors of vertical axis wind turbines (Darrieus H-rotor-type) and calculations of aerodynamic characteristics of these devices. One presented the computational algorithm based on the idea of the partition of the axial rotor on elementary rotors and the conformal mapping of aerofoil cascades on axis-symmetrical surfaces on flat straight cascades in which flow through the cascade and it aerodynamic characteristics are calculated by the method of hydrodynamic singularities.

14

O możliwości zwiększenia współczynnika mocy turbiny wiatrowej o pionowej osi obrotu

Rajca R., Stacharska-Targosz J.

Czasopismo Techniczne. Mechanika

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2004

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R. 101, z. 13-M

93--102

PL

W pracy przedstawiono wybrane wyniki badań doświadczalnych oraz numerycznych dwóch modeli: łopaty oraz łopaty z elementem sterującym o symetrycznym kształcie profilu NACA 0012. Przeanalizowano wpływ parametrów geometrycznych na wartości współczynników: siły nośnej, oporu czołowego oraz współczynnika doskonałości. Wyniki obliczeń numerycznych pozwoliły, posługując się metodą strumieniową, na wyznaczenie wartości współczynnika wykorzystania mocy wiatru Cp dla obu rozpatrywanych modeli. Przebieg uzyskanych funkcji Cp = f(zn) wskazuje na zwiększenie pola pod krzywą dla modelu łopaty z elementem sterującym.

EN

In this paper selected experimental and numerical research of two model units: blade and blade with steering element has been presented. All used blade models had a symmetrical shape marked as NACA 0012. During the tests trials and computational calculations influence of geometrical parameters onto value of the lift, drąg and lift/drag ratio coefficients has been analyzed. Computational calculation results, based on stream tube model, made possible to obtain the value of power coefficient Cp for both tested models. In accordance with obtained functions Cp = f(zn) it is possible to say that by using blade with steering element the area under function curve is increasing in comparison with the single blade.