Ducted turbine theory with right angled ducts

Abstract

This paper describes the use of an inviscid approach to model a ducted turbine-also known as a diffuser augmented turbine-and a comparison of results with a particular one-dimensional theory. The aim of the investigation was to gain a better understanding of the relationship between a real duct and the ideal diffuser, which is a concept that is developed in the theory. A range of right angled ducts, which have a rim for a 90° exit angle, were modelled. As a result, the performance of right angled ducts has been characterised in inviscid flow. It was concluded that right angled ducts cannot match the performance of their associated ideal diffuser and that the optimum rotor loading for these turbines varies with the duct dimensions. © Published under licence by IOP Publishing Ltd.