The near wake structure of a vertical axis wind turbine: Including the Development of a 3D Unsteady Free-Wake Panel Method for VAWTs

A 3D unsteady multi-body panel method is developed that can model arbitrary geometries. The method has been specifically designed so that it can handle the blade-wake interactions and viscous wake effects that are important for modelling a vertical axis wind turbine (VAWT). A systematic validation and verification of the model is presented against theoretical and experimental results. Validation of VAWT wake shapes is given in 2D and 3D by comparison with experimental results using several different techniques (smoke-trail, PIV, and water-tank dye injection). A generalized wake structure for a straight bladed VAWT is explained, and how this structure deforms in time and changes with tip speed ratio and height-diameter ratio. General conclusions of this work are offered in addition to suggested topics for future research.Aerospace Engineerin