On the effect of the rotor geometry on the formation and the development of its wake

Abstract

In order to formulate more accurate simple models, the traditional kinematic models should be enriched. Retaining the similarity of the flow in the far-wake region, enrichment can be introduced through machine-dependent far-field profiles. In the present paper this is accomplished by coupling a linear vortex model with a k- ϵ viscous one, for the analysis of the near-wake region. The far-field profiles are then obtained through matching across the inlet plane of the far-wake region selected at an axial distance of approximately 3–4 diameters. The use of a vortex method for the evaluation of the velocity profiles just downstream the rotor gives an account of the effect of the rotor geometry. As a result the far-wake self-similar velocity profiles are no longer depending on only one parameter, i.e. the initial deficit. Instead they depend on the circulation distribution defined by means of the vortex model. Thus this approach can be termed as a multi-parametric wake modelling.