Shrouded Wind and Water Turbine Analytical Model Extensions for Tip Gaps, Center Bodies, and Flow Blockage

ABSTRACT This paper provides improvements to a previously presented simple, accurate, lower order analytical model for predicting the performance of horizontal‐axis shrouded turbines for a wide range of shroud airfoil shapes varying in length, camber, and thickness. The new, extended model incorporates explicit quantitative predictions of those effects due to the presence of turbine rotor tip gaps, rotor hub center bodies, and induced flow blockage within CFD and experimental domains. The resulting model's efficacy is verified through favorable comparisons with a compendium of 15 independently published CFD and experimental studies. For the wide range of configurations assessed, it was found that the simple algebraic expressions of the extended model provided consistently accurate predictions at all operating conditions considered, thereby enabling rapid preliminary design analysis of potential shrouded power systems.