60 CFD Analysis of Multiple VAWTs Sited in Tandem and T-Type Configurations

A recent surge is evident in the industry, academia and at governmental level to focus on the renewable energy resources for power generation. Renewed interest in the vertical axis wind turbine (VAWT) particularly in built-up commercial and residential areas is one such example. A further dimension is to use clustering of small VAWT as a wind farm; albeit very little is available in the literature from CFD analysis perspective. This paper presents a novel 2D CFD analysis of a 2.75m diameter vertical axis wind turbine (VAWT) in wind farm configuration in comparison with a single. The effect of variation of inter-turbine distance from 2 time turbine diameter to 4 times is also studied for these configurations. Each turbine consists of three vertically aligned NACA0022 turbine blades separated apart by an angle of 120° with a chord length of 0.23m. The results presented in this paper correspond to the freestream velocity range from 6- 14 m/sec with a tip speed ratio (TSR) variation from 1 to 4. Interesting results are obtained from the present research for both favorable (T-type configuration in which the VAWT’s are staggered) and adverse (I-type configuration in which the VAWT’s are in tandem) array configurations. A von Karman type vortex shedding is observed in the wake of all the VAWT configurations considered..