An enhanced analytical model for airfoil‐based shrouded wind turbines
M. J. Werle
Abstract
Abstract This paper provides a simple yet accurate lower order model for predicting the performance of shrouded wind turbines for a range of shroud airfoil shapes varying in length, camber, and thickness. The model employs classic thin airfoil aerodynamic principals and is an enhancement of a previous related model developed for shrouded propellers. The new method's accuracy is assessed using inviscid and viscous computational studies employing an actuator‐disc representation for the turbine rotor. Detailed comparisons are made for three shrouds over a full range of rotor loadings. For the range of configurations assessed, it was found that the algebraic solutions from the new method provided very good engineering approximations at all operating conditions considered, thereby enabling rapid preliminary design of shrouded power systems. Additionally, the new model is used to establish a Betz‐like power performance limit for airfoil‐based shrouded turbines.