Maria Cristina Secci
On the Hysteretic Behaviour of Wells Turbines
GHISU, TIZIANO;PUDDU, PIERPAOLO;CAMBULI, FRANCESCO;
2017-01-01
Abstract
The Wells turbine is a self-rectifying axial flow turbine employed in Oscillating Water Column systems to convert low-pressure airflow into mechanical energy. A number of studies highlighted a variation in turbine performance between acceleration and deceleration phases, generally ascribed to the interaction between blade trailing edge vortices and blade boundary layer. This explaination is in opposition with the large existing literature on rapidly pitching airfoils and wings, where it is generally accepted that a hysteretic behavior can be appreciated only at non-dimensional frequencies significantly larger than the ones typically found in Wells turbine. This work presents a critical re-examination of the phenomenon and a new analysis of some of the test cases originally used to explain its origin. The results demonstrate how the behavior of a Wells turbine is not dissimilar to that of an airfoil pitching at very low reduced frequencies and that the causes of the alleged hysteresis are in a different phenomenon.File | Size | Format | |
---|---|---|---|
ATI17_190_Ghisu.pdf open access
Type: versione post-print
Size 1.79 MB
Format Adobe PDF
|
1.79 MB | Adobe PDF | View/Open |
Energy Procedia_126_2017.pdf open access
Description: articolo
Type: versione editoriale
Size 2.12 MB
Format Adobe PDF
|
2.12 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.