Dr. Ravi Kumar
Influence of local internal nonlinear attachments on the global dynamics of circular cylinder undergoing vortex-induced vibration
Thursday, May 8, 2014, 4:00pm | Room 5-217
Circular cylinder undergoing "vortex-induced vibration" (VIV) is a well-known nonlinear fluid-structure interaction phenomenon. An additional element known as "nonlinear energy sink" (NES), consisting of a small mass, a linear damper, and an essentially nonlinear spring, is attached to the rigid circular cylinder undergoing VIV in a laminar incompressible flow. The nonlinear interaction of the NES and fluid via rigid body motion of the cylinder leads to several interesting response regimes of the coupled system of flow-cylinder-NES in laminar VIV regime. The localized nonlinearity of NES leads "targeted energy transfer" (TET) resulting in partial suppression of VIV. Unlike a linear tuned-mass damper to suppress VIV, the NES alters the solution over compete VIV lock-in regime. A descriptive reduced-order model is developed using the computational data to study the global dynamics of the coupled system.
Ravi Kumar R. Tumkur received his B.Tech. degree in Mechanical Engineering from National Institute of Technology Calicut, India, in 2002. He obtained his M.Tech. degree in Design Engineering from Indian Institute of Technology Delhi, India, in 2006. He worked as engineer for two years after B.Tech with Bajaj Auto Ltd and three years after M.Tech with General Electric-Aviation. He received his PhD degree in Aerospace Engineering at University of Illinois at Urbana-Champaign in 2013. His research interest includes fluid-structure interaction, structural dynamics, and nonlinear dynamics.