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

Abstract

There is a demand of analyzing tilted Vertical Axis Wind Turbine (VAWT) for the emerging applications like VAWTs operating on high rise buildings, Floating Axis Wind Turbine (FAWT) functioning in deep sea, and so on. For this purpose numerical validation of an existing experimental work of Vertical Axis Wind Turbine (VAWT) in upright and tilted conditions has been carried out. The numerical validation is accomplished by means of Computational Fluid Dynamics (CFD) analysis by solving Unsteady Reynolds Averaged Navier-Stokes (URANS) equation. A rigorous parametric study of choosing a right turbulence model for solving URANS equation, mesh dependency analysis and optimum time step is comprehended. After choosing the right parameters, validation is performed. Following that the flow fields of upright and tilted conditions are visualized. The possible reasons of getting higher power coefficient in tilted condition have been discussed. While carrying out the study, it is observed that in case of tilted configuration the wake stream shifts downward. This feature of VAWT in tilted condition could lead into effective sea surface utilization in floating offshore wind farms.