Performance Evaluation of Novel Spline-Curved Blades of a Vertical Axis Wind Turbine Based on the Savonius Concept

2016 ◽  
Author(s):  
Michele Mari ◽  
Mauro Venturini ◽  
Asfaw Beyene
Keyword(s):  
Fluid Dynamic ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Vertical Axis ◽  
Cfd Analysis ◽  
The Novel ◽  
Turbulent Model ◽  
Vertical Axis Wind Turbine ◽  
Laboratory Results ◽  
Central Shaft

In this study, we present the results of a two-dimensional fluid-dynamic simulation of novel rotor geometry with spline function which is derivative of the traditional S-shape Savonius blade. A Computational Fluid Dynamic (CFD) analysis is conducted using the Spalart-Allmaras turbulent model, validated using experimental data released by Sandia National Laboratory. Results are presented in terms of dimensionless torque and power coefficients, assuming a wind speed of 7 m/s and height and rotor diameter of 1 m. Furthermore, analysis of the forces acting on the rotor is conducted by evaluating frontal and side forces on each blade, and the resultant force acting on the central shaft. A qualitative representation of the vorticity around the traditional and spline rotor is shown to prove that the novel blade is more “flow-friendly”, thus the air flow is less turbulent through the rotor. Finally, energy conversion capability of the Savonius turbines is estimated in parametric form for both the traditional and spline-curved geometry.

A Novel Geometry for Vertical Axis Wind Turbines Based on the Savonius Concept

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Michele Mari ◽  
Mauro Venturini ◽  
Asfaw Beyene
Keyword(s):  
Fluid Dynamic ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Vertical Axis ◽  
The Novel ◽  
Turbulent Model ◽  
Vertical Axis Wind Turbines ◽  
Laboratory Results ◽  
Flow Through ◽  
Central Shaft

In this study, we present the results of a two-dimensional fluid-dynamic simulation of novel rotor geometry with spline function which is derivative of the traditional S-shape Savonius blade. A computational fluid dynamic (CFD) analysis is conducted using the Spalart–Allmaras turbulent model, validated using experimental data released by Sandia National Laboratory. Results are presented in terms of dimensionless torque and power coefficients, assuming a wind speed of 7 m/s and height and rotor diameter of 1 m. Furthermore, analysis of the forces acting on the rotor is conducted by evaluating frontal and side forces on each blade, and the resultant force acting on the central shaft. A qualitative representation of the vorticity around the traditional and spline rotor is shown to prove that the novel blade allows less turbulent flow through the rotor.

Performance of a Darrieus turbine on the roof of a building

2018 ◽  
Vol 42 (4) ◽  
pp. 341-349 ◽  
Author(s):  
Samson Victor ◽  
Marius Paraschivoiu
Keyword(s):  
Urban Areas ◽  
Fluid Dynamic ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Wind Generation ◽  
Speed Ratio ◽  
Cfd Analysis ◽  
Vertical Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
General Rules

Various efforts have been made to introduce micro wind turbines in urban areas. Their onsite wind generation can be beneficial, but general rules about their ideal placement in terms of energy extraction need to be identified. This paper investigates the performance of a Darrieus turbine when installed on the roof of a building and offers a rare analysis of the synergy between the turbine and the building. This study focuses on computational fluid dynamic (CFD) analysis of a vertical-axis wind turbine mounted on the upstream edge of a building. The CFD methodology is validated by comparing the calculated performance with experimental data. Three different turbine positions at different heights are investigated to capture the Cp–λ curve sensitivity. Positions 1 and 2 are at the edge of the building, whereas position 3 is a few meters away from the edge, directed towards the geometric center of the building. To simulate realistic atmospheric wind conditions, an atmospheric boundary layer is imposed at the inlet. The results show that the power coefficient is higher compared with a standalone turbine and that the location of the turbine on the building clearly affects the value of the tip-speed ratio at maximum power coefficient.

Computational fluid dynamic analysis of roof-mounted vertical-axis wind turbine with diffuser shroud, flange, and vanes

2018 ◽  
Vol 42 (4) ◽  
pp. 404-415
Author(s):  
H. Abu-Thuraia ◽  
C. Aygun ◽  
M. Paraschivoiu ◽  
M.A. Allard
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Guide Vane ◽  
Fluid Dynamic ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes ◽  
Turbine Design

Advances in wind power and tidal power have matured considerably to offer clean and sustainable energy alternatives. Nevertheless, distributed small-scale energy production from wind in urban areas has been disappointing because of very low efficiencies of the turbines. A novel wind turbine design — a seven-bladed Savonius vertical-axis wind turbine (VAWT) that is horizontally oriented inside a diffuser shroud and mounted on top of a building — has been shown to overcome the drawback of low efficiency. The objective this study was to analyze the performance of this novel wind turbine design for different wind directions and for different guide vanes placed at the entrance of the diffuser shroud. The flow field over the turbine and guide vanes was analyzed using computational fluid dynamics (CFD) on a 3D grid for multiple tip-speed ratios (TSRs). Four wind directions and three guide-vane angles were analyzed. The wind-direction analysis indicates that the power coefficient decreases to about half when the wind is oriented at 45° to the main axis of the turbine. The analysis of the guide vanes indicates a maximum power coefficient of 0.33 at a vane angle of 55°.

Mechanical engineering with solidwork flow simulation improving and supporting undergraduate student learning in mechanical engineering courses: Fluid dynamic course

2018 ◽  
Vol 5 (4) ◽  
pp. 45-51
Author(s):  
Youssef Kassem ◽  
Ramzi Asteg Faraj ◽  
Huseyin Camur
Keyword(s):  
Undergraduate Students ◽  
Computer Aided Design ◽  
Mechanical Engineering ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Vertical Axis ◽  
Virtual Laboratory ◽  
Vertical Axis Wind Turbine ◽  
Engineering Department

The computer-aided design programs such as Solidwork flow simulation (SWFS) provide powerful, engaging, hands-on software to understand and develop designs for the real world. SWFS can be considered as a virtual laboratory. The purpose of this study is to show that using SWFS will help the undergraduate students to understand the concepts of fluid dynamic course in the Mechanical Engineering Department. This paper presents an example of the effect of both the temperature and density on the stream flow characteristics around a vertical axis wind turbine using SWFS. Moreover, the use of the SWFS in engineering education is shown by an important experiment taken from the field of mechanical engineering.Keywords: Fluid dynamic, mechanical engineering, SWFS, virtual laboratory.

Comparative CFD analysis of Vertical Axis Wind Turbine in upright and tilted configuration

2016 ◽  
Vol 85 ◽  
pp. 327-337 ◽  
Author(s):  
Abdullah Mobin Chowdhury ◽  
Hiromichi Akimoto ◽  
Yutaka Hara
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Cfd Analysis ◽  
Vertical Axis Wind Turbine

Aerodynamic Measurements on a Vertical Axis Wind Turbine in a Large Scale Wind Tunnel

2010 ◽  
Author(s):  
L. Battisti ◽  
L. Zanne ◽  
S. Dell’Anna ◽  
V. Dossena ◽  
B. Paradiso ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Fluid Dynamic ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Aerodynamic Optimization ◽  
Vertical Axis Wind Turbines

This paper presents the first results of a wide experimental investigation on the aerodynamics of a vertical axis wind turbine. Vertical axis wind turbines have recently received particular attention, as interesting alternative for small and micro generation applications. However, the complex fluid dynamic mechanisms occurring in these machines make the aerodynamic optimization of the rotors still an open issue and detailed experimental analyses are now highly recommended to convert improved flow field comprehensions into novel design techniques. The experiments were performed in the large-scale wind tunnel of the Politecnico di Milano (Italy), where real-scale wind turbines for micro generation can be tested in full similarity conditions. Open and closed wind tunnel configurations are considered in such a way to quantify the influence of model blockage for several operational conditions. Integral torque and thrust measurements, as well as detailed aerodynamic measurements were applied to characterize the 3D flow field downstream of the turbine. The local unsteady flow field and the streamwise turbulent component, both resolved in phase with the rotor position, were derived by hot wire measurements. The paper critically analyses the models and the correlations usually applied to correct the wind tunnel blockage effects. Results evidence that the presently available theoretical correction models does not provide accurate estimates of the blockage effect in the case of vertical axis wind turbines. The tip aerodynamic phenomena, in particular, seem to play a key role for the prediction of the turbine performance; large-scale unsteadiness is observed in that region and a simple flow model is used to explain the different flow features with respect to horizontal axis wind turbines.

scholarly journals Effect of Blade Design on Angular Velocity of Vertical Axis Wind Turbine – CFD Analysis

2018 ◽  
Vol 10 (1-2) ◽  
pp. 279-285
Author(s):  
Prakash C Arun ◽  
Ilangovan P. Ponsuganth ◽  
Nitin Joy ◽  
R. Subramanian
Keyword(s):  
Angular Velocity ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Blade Design ◽  
Cfd Analysis ◽  
Vertical Axis Wind Turbine

Numerical Study to Quantify the Effects of Struts and Central Hub on the Performance of a Three Dimensional Vertical Axis Wind Turbine Using Sliding Mesh

2013 ◽  
Author(s):  
M. Salman Siddiqui ◽  
Naveed Durrani ◽  
Imran Akhtar
Keyword(s):  
Wind Turbine ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Unit Length ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Torque Ripple ◽  
Outer Diameter ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh

A computational fluid dynamic (CFD) analysis is carried out to investigate the effects of struts and central hub in 3D on the overall performance prediction of a three dimensional vertical axis wind turbine (VAWT) with three Darrieus H-type blades. The VAWT has the outer diameter of 2.5m and finite unit length height with expected output of 2KVA. This type of small VAWT are expected to perform better on roof tops of the built-up urban area. The analysis is carried out using sliding mesh concept in commercial CFD software ‘Ansys Fluent 13’. It is observed that the struts and central hub assembly induce additional drag and generate strong vortices which caused a substantial decrease in the performance parameters of the turbine. The numerical simulation are carried out over a three dimensional VAWT with and without struts and central hub. It is found that both the cases show a similar trend of the torque ripple for any one blade while for the upstream path, on the contrary the blades experience a drop in performance from 220° to 360° due to the struts and central hub assembly. A detailed comparative analysis between both the cases is made over the TSR values range from 1.5 to 4.5. At TSR = 1.5, the performance coefficient of the cases with and without struts and central hub are same. However, for the case of struts and central hub, TSR 4 and above show negative values of power coefficients.

Sign in / Sign up

Export Citation Format

Share Document