Active decoupling of the axisymmetric body wake response to a pitching motion. (November 2015)

• Record Type: Journal Article
• Authors: Lambert, Thomas J.; Vukasinovic, Bojan; Glezer, Ari
• Is Part Of: Journal of fluids and structures. Volume 59(2015:Nov.)
• Page Start: 129
• Page End: 145
• Publication Date: 2015-11
• Subjects: flow control -- axisymmetric body -- wake; Fluid-structure interaction -- Periodicals; Fluid mechanics -- Periodicals; Structural dynamics -- Periodicals; Structural analysis (Engineering) -- Periodicals; 620.106
• DOI: 10.1016/j.jfluidstructs.2015.08.017
• Languages: English
• ISSNs: 0889-9746

Abstract

Abstract: Controlled interactions between fluidic actuators and the cross flow over the aft end of a wire-mounted axisymmetric wind tunnel bluff body model ( Re D =2.3·10 5 ) are exploited for modification of the near wake dynamics, and the consequent global aerodynamic loads. Actuation is effected using an array of four aft-facing synthetic jet modules through narrow, azimuthally-segmented slots that are equally distributed around the perimeter of the tail end. The model is supported by eight wires, each including a miniature inline force transducer for measurements of the time-resolved tension. The model's position is varied in a prescribed trajectory by synchronous activation of shape memory alloy (SMA) segments in each of the mounting wires, and the aerodynamic forces and moments are manipulated over a range of pitch attitude. The effectiveness of the flow control approach is demonstrated by decoupling of the wake response from the body's pitch motion at a low pitch frequency ( k =0.013). It is shown that, under the active control, the wake symmetry can be restored or its asymmetry can be amplified.