Power production locality of bluff body flutter mills using fully coupled 2D direct numerical simulation

• Published in: Journal of fluids and structures Vol. 28; pp. 456 - 472
• Main Authors: Kuhl, J.M., DesJardin, P.E.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2012; Elsevier
• Subjects: Bluff bodies; Cantilever plates; Computational fluid dynamics; Computational methods in fluid dynamics; Curvature; Exact sciences and technology; Flow induced vibration; Fluid dynamics; Fluid structure interaction; Flutter; Fundamental areas of phenomenology (including applications); Mathematical analysis; Mathematical models; Navier-Stokes equations; Physics; Solid mechanics; Structural and continuum mechanics; Two dimensional; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Flow induced vibration; Flutter; Fluid structure interaction; Wind; Vibration; Computational fluid dynamics; Bluff body; Contour line; Finite volume method; Modeling; Wake; Deformable body; Cantilever beam; Finite element method; Navier Stokes equation; Cantilever plate; Kinematics; Circular cylinder; Aeroelasticity; Curvature; Energy transfer; Probability measure
• ISSN: 0889-9746; 1095-8622
• DOI: 10.1016/j.jfluidstructs.2011.12.005

Two-dimensional, fully coupled direct numerical simulations (DNS) are conducted to examine the local energy dynamics of a flexible cantilevered plate in the wake of a two-dimensional circular cylinder. The motion of the cantilevered plate is described using a finite element formulation and a fully compressible, finite volume Navier Stokes solver is used to compute the flow field. A sharp interface level set method is employed in conjunction with a ghost fluid method to describe the immersed boundaries of the bluff body and flexible plate. DNS is first conducted to validate the numerical methodology and compared with previous studies of flexible cantilevered plates and flow over bluff bodies; excellent agreement with previous results is observed. A newly defined power production/loss geometry metric is introduced based on surface curvature and plate velocity. The metric is found to be useful for determining which sections of the plate will produce energy based on curvature and deflection rate. Scatter plots and probability measures are presented showing a high correlation between the direction of energy transfer ( i.e., to or from the plate) and the sign of the newly defined curvature-deflection-rate metric. The findings from this study suggest that a simple local geometry/kinematic based metric can be devised to aid in the development and design of flexible wind energy harvesting flutter mills.