Wind loads and Control of Flexible Structures Embedded in a Turbulent Boundary Layer

摘要

We investigate experimentally the flow around a flexible rectangularrnthin plate positioned normal to the wind direction and embedded in a thickrnturbulent boundary layer. The purpose of the study is to reduce the platernoscillations caused by unsteady wind loads. Two methods were tested. Firstrnwe used two mechanical Piezo-electric actuators attached to the plate whilernthe second method used three mass-less Piezo-electric fluidic actuators.rnThe two methods were applied with similar closed-loop control principles:rnStrain Gauge (SG) sensors captured the plate’s oscillations and a simplernphase-lag and gain was used to attenuate the oscillations. The results showrna reduction of 20-30% of the plate oscillation compared to the uncontrolledrncase, while a similar increase is possible. The fluidic control was found tornbe superior to the mechanical control for the current application andrnconditions. Hypothesized flow physics mechanism link the unsteadyrnpressures created over the plate by actuation to its oscillations.