Aeroelastic Response of a Vortex-Induced Vibrating Cylinder

Speaker: 
Fanny Besem
Date of Seminar: 
Fri, 2013-11-15 12:00
Semester & Year: 
Fall 2013
Seminar Location: 
Friday, Nov. 15, 12:00 Noon. FREE Lunch. Room: TBD
Seminar Contact(s): 
Wes Ross (weston.ross@duke.edu), Fanny Besem (fb46@duke.edu)
Special Instructions: 
FREE Lunch Provided!

Abstract

Beyond a certain speed, flow passing a cylinder separates and leads to a pattern of unsteady swirling vortices. Under certain conditions, this shedding may cause the cylinder to respond in an aeroelastic limit cycle oscillation, sometimes at a very large amplitude of motion. A similar phenomenon can occur in jet engines. For instance, shedding flow within a compressor may lead to large amplitude blade vibrations, which in turn could result in structural fatigue and eventual failure. The accurate prediction of such unsteady shedding flows requires the use of computational fluid dynamics (CFD) methods which are computationally expensive and not practical for preliminary design purposes.

This research presents a novel reduced order model approach for predicting the aeroelastic response of a cylinder in crossflow. The flow reduced order model is then coupled with the structural equations of the cylinder and its suspension system. The resulting aeroelastic model is solved to obtain the cylinder unsteady response amplitude at different flow speeds, at a greatly reduced computational cost.

Biography

Fanny is a second year Ph.D. student in Mechanical Engineering and Materials Science at Duke University. Born and raised in Belgium, she graduated from the University of Liège in Belgium with a B.A.Sc. in Mechanics and Physics. After graduation, she took part in the first batch of the THRUST international master program. She studied turbomachinery for a year in Sweden, surviving the cold winter, before enjoying the North Carolina climate while at Duke. Fanny’s research focuses on the prediction of aerodynamic instabilities in jet engines with Dr. Robert Kielb. This project is a first step toward the accurate prediction of these dangerous vibrations using flow simulation based tools and it has been presented a couple of weeks ago at an ASME conference.