scholarly journals CFD SIMULATION AND VISUALIZATION BASED INVESTIGATION OF SMALL WIND TURBINE POTENTIAL: A CASE STUDY “NEUER STÖCKACH” FOR STUTTGART

2021 ◽  
Vol VIII-4/W1-2021 ◽  
pp. 17-24
Author(s):  
M. Brennenstuhl ◽  
M. von der Gruen ◽  
S. Harbola ◽  
A. Koukofikis ◽  
R. Padsala ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Urban Areas ◽  
Cfd Simulation ◽  
Low Voltage ◽  
Global Radiation ◽  
Energy Transition ◽  
Small Wind Turbine ◽  
Energy Concept ◽  
Small Wind Turbines

Abstract. In the face of climate change and the energy transition that the German federal government is aiming for, all renewable energy potentials need to be tapped. Unfortunately, small wind turbines play a niche role in Germany and most other countries despite the fact, that although they offer advantages as e.g. almost seasonal independent energy production in close proximity to the consumer on the same low-voltage grid level. One reason beside the lower wind speeds that can be expected closer to the ground is, that in comparison to PV (photovoltaic), for which good yield forecasts can be made using global radiation measurements from nearby weather stations or online databases, the yield of small wind turbines, especially in urban areas, can only be forecasted using on-site measurements due to the influence of the surrounding buildings and topography. This method is time-consuming and costly. To address this, within this work a Computational Fluid Dynamics (CFD) simulation based visualization framework for the investigation of the small wind turbine potential is presented. In this specific case the energy supply company EnBW is planning to refurbish the “Neuer Stöckach” urban quarter on the former “Stöckach” company site. As part of the redevelopment, a comprehensive energy concept is planned to integrate renewable energies. In this context the integration of small wind turbines into the energy concept is examined according to this new methodology.

Computational Investigation of a Shrouded Vertical Axis Wind Turbine

2016 ◽  
Author(s):  
K. Vafiadis ◽  
H. Fintikakis ◽  
I. Zaproudis ◽  
A. Tourlidakis
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Urban Areas ◽  
Numerical Study ◽  
Flow Analysis ◽  
Vertical Axis ◽  
Green Energy ◽  
Vertical Axis Wind Turbine ◽  
Wide Range ◽  
Small Wind Turbines

In urban areas, it is preferable to use small wind turbines which may be integrated to a building in order to supply the local grid with green energy. The main drawback of using wind turbines in urban areas is that the air flow is affected by the existence of nearby buildings, which in conjunction with the variation of wind speed, wind direction and turbulence may adversely affect wind energy extraction. Moreover, the efficiency of a wind turbine is limited by the Betz limit. One of the methods developed to increase the efficiency of small wind turbines and to overcome the Betz limit is the introduction of a converging – diverging shroud around the turbine. Several researchers have studied the effect of shrouds on Horizontal Axis Wind Turbines, but relatively little research has been carried out on shroud augmented Vertical Axis Wind Turbines. This paper presents the numerical study of a shrouded Vertical Axis Wind Turbine. A wide range of test cases, were examined in order to predict the flow characteristics around the rotor, through the shroud and through the rotor – shroud arrangement using 3D Computational Fluid Dynamics simulations. The power output of the shrouded rotor has been improved by a factor greater than 2.0. The detailed flow analysis results showed that there is a significant improvement in the performance of the wind turbine.

Feasibility of Small Wind Turbine via Net Metering in Greek Islands

2021 ◽  
Vol 1 (1) ◽  
pp. 23-28
Author(s):  
D. Daskalaki ◽  
J. Fantidis ◽  
P. Kogias
Keyword(s):  
Wind Speed ◽  
Greenhouse Gases ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Average Wind Speed ◽  
Small Wind Turbine ◽  
Net Metering ◽  
Average Wind ◽  
Environmental Criteria ◽  
Small Wind Turbines

The evaluation of a small 3kW wind turbine through the net metering scheme is studied in this article. 14 near to sea locations in Greece examined with the help of the RetScreen expert software. The simulations based on electrical, financial and environmental criteria. Siros with average wind speed of 6.93 m/s is the most attractive area while Iraklion is the least attractive location. According to the results the simulated project is already economically sound and a small wind turbine in the Greek islands will become a progressively an even more financially source of electricity in Greece. Finally yet importantly is the fact that the use of small wind turbines has as a result that significant amount of Greenhouse gases do not reradiate into the topical atmosphere.

Power Quality Measurements of a Horizontal Axial Small Wind Turbine

2017 ◽  
Vol 870 ◽  
pp. 329-334
Author(s):  
Yu Jen Liu ◽  
Yen Chang Chen ◽  
Pei Hsiu Lan ◽  
Tsang Pin Chang
Keyword(s):  
Wind Turbine ◽  
Power Quality ◽  
Wind Turbines ◽  
Distribution System ◽  
Large Scale ◽  
Low Voltage ◽  
System Structure ◽  
System Level ◽  
Small Wind Turbines ◽  
Quality Measurements

As small wind turbines are increasingly used, the assessments of power quality may thus become paramount. Unlike the large-scale wind turbines which are optional required to perform power quality measurements during production certification stage; however the power quality measurements are often neglected in small wind turbines since they are not requested on the certain of national grid codes at low-voltage distribution system level. Considering the high penetrations of small wind turbines may be connected to the future urban electric network, the paper performs the power quality on-site measurements of a horizontal axle small wind turbines. The issues may include the discussion of measurement system structure, the description of measurement method, and the analysis of wind turbine power characteristic, voltage/current trends, harmonics and flicker phenomena. The measured data collected in the study will valuable for the further analysis of power systems connected with the small wind turbines.

scholarly journals Using TurbSim stochastic simulator to improve accuracy of computational modelling of wind in the built environment

2018 ◽  
Vol 43 (2) ◽  
pp. 147-161
Author(s):  
Amir Bashirzadeh Tabrizi ◽  
Binxin Wu ◽  
Jonathan Whale ◽  
Maryam Shahabi Lotfabadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Turbulent Flow ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Flow Conditions ◽  
Small Wind Turbine ◽  
Small Wind Turbines ◽  
Stochastic Simulator ◽  
Turbulent Flow Conditions

Small wind turbines are often sited in more complex environments than in open terrain. These sites include locations near buildings, trees and other obstacles, and in such situations, the wind is normally highly three-dimensional, turbulent, unstable and weak. There is a need to understand the turbulent flow conditions for a small wind turbine in the built environment. This knowledge is crucial for input into the design process of a small wind turbine to accurately predict blade fatigue loads and lifetime and to ensure that it operates safely with a performance that is optimized for the environment. Computational fluid dynamics is a useful method to provide predictions of local wind flow patterns and to investigate turbulent flow conditions at small wind turbine sites, in a manner that requires less time and investment than actual measurements. This article presents the results of combining a computational fluid dynamics package (ANSYS CFX software) with a stochastic simulator (TurbSim) as an approach to investigate the turbulent flow conditions on the rooftop of a building where small wind turbines are sited. The findings of this article suggest that the combination of a computational fluid dynamics package with the TurbSim stochastic simulator is a promising tool to assess turbulent flow conditions for small wind turbines on the roof of buildings. In particular, in the prevailing wind direction, the results show a significant gain in accuracy in using TurbSim to generate wind speed and turbulence kinetic energy profiles for the inlet of the computational fluid dynamics domain rather than using a logarithmic wind-speed profile and a pre-set value of turbulence intensity in the computational fluid dynamics code. The results also show that small wind turbine installers should erect turbines in the middle of the roof of the building and avoid the edges of the roof as well as areas on the roof close to the windward and leeward walls of the building in the prevailing wind direction.

scholarly journals Holistic simulation of wind turbines with fully aero-elastic and electrical model

2021 ◽  
Author(s):  
Marcus Wiens ◽  
Sebastian Frahm ◽  
Philipp Thomas ◽  
Shoaib Kahn
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Elastic Model ◽  
Electrical Model ◽  
Holistic Model ◽  
Electric System ◽  
Electrical Components

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.

Fast CFD Simulation of Horizontal Axis Wind Turbines

2010 ◽  
Author(s):  
Fabio De Bellis ◽  
Luciano A. Catalano ◽  
Andrea Dadone
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Cfd Simulation ◽  
Flow Distribution ◽  
Horizontal Axis ◽  
Wall Functions ◽  
Mesh Topology ◽  
Numerical Predictions ◽  
Horizontal Axis Wind Turbines ◽  
Time Required

The numerical simulation of horizontal axis wind turbines (HAWT) has been analysed using computational fluid dynamics (CFD) with the aim of obtaining reliable but at the same time affordable wind turbine simulations, while significantly reducing required overall resources (time, computational power, user skills), for example in an optimization perspective. Starting from mesh generation, time required to extract preliminary aerodynamic predictions of a wind turbine blade has been shortened by means of some simplifications, i.e.: fully unstructured mesh topology, reduced grid size, incompressible flow assumption, use of wall functions, commercial available CFD package employment. Ansys Fluent software package has been employed to solve Reynolds Averaged Navier Stokes (RANS) equations, and results obtained have been compared against NREL Phase VI campaign data. The whole CFD process (pre-processing, processing, postprocessing) has been analysed and the chosen final settings are the result of a trade-off between numerical accuracy and required resources. Besides the introduced simplifications, numerical predictions of shaft torque, forces and flow distribution are in good agreement with experimental data and as accurate as those calcuted by other more sophisticated works.

Nondimensional Parameters’ Effects on Hybrid Darrieus–Savonius Wind Turbine Performance

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Armin Roshan ◽  
Amir Sagharichi ◽  
Mohammad Javad Maghrebi
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Power Output ◽  
Urban Areas ◽  
Model Performance ◽  
Vertical Axis ◽  
Favorable Effect ◽  
Turbine Performance ◽  
Primary Model ◽  
Overlap Ratio

Abstract Vertical axial wind turbines are the most commonly used turbines in residential and urban areas. This paper investigates the effect of combining Darrieus and Savonius wind turbines on power output and introduces a wind turbine with high starting torque addition to the wide working domain. A two-dimensional computational fluid dynamics transient simulation is developed, and a moving mesh is implemented for rotating moving parts. Comprehensive research has been carried out to investigate the effects of the initial overlap ratio (ɛ), arc angle Ø, and curvature (α) of Savonius blades on the performance of the turbine and 18 models are simulated at seven tip speed ratios. The results showed that combining the Darrieus turbine with the Savonius turbine has a favorable effect on self-starting performance. Also, it was observed that by changing each of the parameters, the primary model performance could be significantly improved. Finally, it is concluded that ɛ = 0.25, α = 0.25, and ∅ = 150 deg are the optimum values of the parameters which increase turbine power output compared to conventional vertical-axis turbines.

scholarly journals Experimental Vibration Analysis of a Small Scale Vertical Wind Energy System for Residential Use

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 35 ◽  
Author(s):  
Francesco Castellani ◽  
Davide Astolfi ◽  
Mauro Peppoloni ◽  
Francesco Natili ◽  
Daniele Buttà ◽  
...  
Keyword(s):  
Wind Turbines ◽  
Urban Areas ◽  
Wind Farm ◽  
Vertical Axis ◽  
Energy System ◽  
Small Scale ◽  
Main Research ◽  
Small Wind Turbines ◽  
Low Sensitivity ◽  
A Minor

In the recent years, distributed energy production has been one of the main research topics about renewable energies. The decentralization of electric production from wind resources raises the issues of reducing the size of generators, from the MW scale of industrial wind farm turbines to the kW scale, and possibly employing them in urban areas, where the wind flow is complex and extremely turbulent because of the presence of buildings and obstacles. On these grounds, the use of small-scale vertical axis small wind turbines (VASWT) is a valid choice for on-site generation (OSG), considering their low sensitivity with respect to turbulent flow and that there is no need to align the turbine with wind direction, as occurs with horizontal axis small wind turbines (HASWT). In addition, VASWTs have a minor acoustic impact with respect to HASWTs. The aim of this paper is to study the interactions that take place between a 1.2 kW, vertical axis, Darrieus VASWT turbine and a small, experimental building, in order to analyze the noise and the vibrations transmitted to the structure. One method to damp the vibrations is then assessed through spectral analysis of data acquired through accelerometers located both in the mast of the wind turbine and at the building walls. The results confirm the usefulness of dampers to increase the building comfort regarding vibrations.

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