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COBEM 2017
24th ABCM International Congress of Mechanical Engineering
NUMERICAL INVESTIGATION AT LOW REYNOLDS NUMBERS OF THE GALLOPING INSTABILITY OF A CIRCULAR CYLINDER WITH A SPLITTER PLATE EMPLOYING A SPECTRAL/HP FINITE ELEMENT METHOD
Submission Author:
Robin Basso , SP
Co-Authors:
Robin Basso, Gustavo Roque da Silva Assi, Reinaldo Marcondes Orselli, Fabio Saltara
Presenter: Robin Basso
doi://10.26678/ABCM.COBEM2017.COB17-0097
Abstract
This paper presents a numerical investigation of the forces acting on a circular cylinder of diameter D fitted with a rigid, fixed splitter plate of length D and thickness l = 0.1D, submerged in a steady flow of velocity U at an incidence angle α. Fluid forces are employed in a quasi-steady model of the dynamics system based on the classical theory of galloping instability. We first remember the range of validity of the quasi-steady theory in each degree of freedom (plunge and torsion) in a view to justify the size our geometry. Then we describe the numerical method we used, and our results for Reynolds numbers equal to 60 and 200. Secondly, we visualize the flow behavior around the body and note that it behaves as a bluff body. Then we focus on the steady aerodynamic coefficients for each angle of attack, and investigate the way to better extract the values for their derivatives. Afterwards, we show that regarding the Den Hartog’s criterion for the stability of classical galloping (stability in plunge), there is no potential instability for the system at both Reynolds numbers. The validity of a quasi-steady approach to model a complex fluid-structure interaction problem is also discussed.
Keywords
Quasi-Steady model, CFD, galloping, FEM, DNS
