Journal of Fundamentals of Renewable Energy and Applications
Open Access

The effect of the upstream wind conditions on the performance of a vertical axis wind turbine

World Congress and Exhibition on Wind & Renewable Energy

July 28-30, 2016 Berlin, Germany

Ava Shahrokhi, Mahyar Mahmoodilari, Ioannis Bouras, Derek Ingham, Lin Ma and Mohammed Pourkashanian

University of Sheffield, UK

Scientific Tracks Abstracts: J Fundam Renewable Energy Appl

Abstract :

The effect of the upstream velocity profile on the performance of a rotating vertical axis wind turbine has been investigated using the SST k-Ï�? turbulence model in unsteady flow conditions. This study is a part of the European Project â�?�?New innovative solutions, components and tools for the integration of wind energy in urban and peri-urban areas (acronym SWIP)â�?. Recently more vertical axis wind turbines (VAWTs) have been installed in urban areas than before. This is due to the fact that VAWTs are more appropriate for urban regions than Horizontal Axis Wind Turbines (HAWTs). They are known to perform better in urban regions compared to horizontal axis wind turbines as they do not require alignment to the oncoming air flow. However, the wind flow speed in urban regions is substantially influenced by the structure of the buildings in the location that the turbine is to be installed. This includes changes in the angle of attack and formation of a vortex flow in the upstream wind that will alter the performance of the wind turbine. This work involves numerical simulation of the air flow around VAWT blades that is installed on the roof of a building. A turbulent velocity profile has been considered at the inlet which is exposed to the building obstacle before it encounters the VAWT. The computational fluid dynamics techniques will be based on Reynolds averaging of the unsteady Navier-Stokes equations (URANS). Since flow separation and in particular dynamic stall, are key flow processes occurring in such applications, the transient SST k-Ï�? is the most appropriate turbulence model for wind turbine flow simulations with dynamic stalls. Therefore, this turbulence modelling scheme is utilized for the simulations of the VAWT. The results of the disturbed air flow around the turbine are compared with the case of an undisturbed wind at the inlet.

Biography :

Ava Shahrokhi is a Research Fellow in the Energy Group in the Department of Mechanical Engineering of the University of Sheffield. She was awarded her PhD at the Department of Aerospace of the Amirkabir University in Tehran in 2009. Her research interest is generally on computational fluid dynamics (CFD) and she is currently focused on large eddy simulation in wind resource assessment of urban and pre-urban areas. This is a part of a major project of design, manufacture and installation of small/medium wind turbines which involves several industrial and academic partners from all around Europe.

Email: a.shahrokhi@sheffield.ac.uk