Determining the performance of a Diffuser Augmented Wind Turbine using a combined CFD/BEM method

Abstract

Abstract. Traditionally, the optimisation of a Diffuser Augmented Wind Turbine has focused on maximising power output. However, due to the often less than ideal location of small-scale turbines, cut-in speed and starting time are of equal importance in maximising Annual Energy Production, which is the ultimate goal of any wind turbine design. This paper proposes a method of determining power output, cut-in speed and starting time using a combination of Computational Fluid Dynamics and Blade Element Momentum theory. The proposed method has been validated against published experimental data.

Numerical Investigation of Power Output and Flow Visualization of Straight blade Vertical Axis Wind Turbine Integrated with Wind Accelerator

“…Laboratory measurements showed that improvements were obtained on electrical output, resulting in a maximum increase of 120 %. Measurements showed a power augmentation by a factor about 1.5-2.3, compared with the rotor without the shroud [28]. Therefore augmentation device/ diffuser concept can offer several benefits in the future electrical generation.…”

Finite blade functions and blade element optimization for diffuser-augmented wind turbines

“…Hansen [8]. The diffuser can be modeled using computational fluid dynamics (CFD), e.g, [3] and Kesby et al [9], and, clearly, its performance is influenced by interaction with the blades. If CFD is not used, it is often assumed that the diffuser is perfectly efficient, although methods to include finite efficiency have been available for a long time, e.g.…”