Title

Wind Tunnel Blockage Corrections: Review and Application to Savonius Vertical-Axis Wind Turbines

Document Type

Article

Publication Date

5-2011

Publication Source

Journal of Wind Engineering and Industrial Aerodynamics

Abstract

An investigation into wake and solid blockage effects of vertical axis wind turbines (VAWTs) in closed test-section wind tunnel testing is described. Static wall pressures have been used to derive velocity increments along wind tunnel test section which in turn are applied to provide evidence of wake interference characteristics of rotating bodies interacting within this spatially restricted domain. Vertical-axis wind turbines present a unique aerodynamic obstruction in wind tunnel testing, whose blockage effects have not yet extensively investigated. The flowfield surrounding these wind turbines is asymmetric, periodic, unsteady, separated and highly turbulent. Static pressure measurements are taken along a test-section sidewall to provide a pressure signature of the test models under varying rotor tip-speed ratios (freestream conditions and model RPMs). Wake characteristics and VAWT performance produced by the same vertical-axis wind turbine concept tested at different physical scales and in two different wind tunnels are investigated in an attempt to provide some guidance on the scaling of the combined effects on blockage. This investigation provides evidence of the effects of large wall interactions and wake propagation caused by these models at well below generally accepted standard blockage figures.

Inclusive pages

523–538

ISBN/ISSN

0167-6105

Comments

Permission documentation is on file.

Publisher

Elsevier

Volume

99

Issue

5

Peer Reviewed

yes