UTA Department of Mathematics

Applied Mathematics Seminar

Date/Time/Room: Friday (9/20/2002) at 2:00pm in 304 Pickard Hall

Speaker: Charles Dalton, Mechanical Engineering Department, University of Houston


``The Calculation of Vortex-Induced Vibrations Using Large Eddy Simulation at Moderate Reynolds Numbers''

Abstract: This presentation will address the subject of the Vortex-induced Vibration (VIV) of a circular cylinder subject to a uniform approach flow. The VIV motion of the cylinder is a natural response due to vortex shedding from the cylinder when certain favorable conditions exist. We have performed a CFD study of this problem which is presently of great interest to the offshore oil industry. The approach taken is to represent this time-dependent problem by a combined finite-difference and spectral method. The Reynolds numbers at which the calculations are made are in the turbulent wake range so the effects of turbulence must be included. The turbulence is represented by means of the Large Eddy Simulation (LES) method. The calculated two-dimensional response of the cylinder to the uniform approach flow is determined over a range of Reynolds numbers, damping factors, mass factors, and natural frequencies. The results show that the vibratory response of the cylinder is accurately predicted and that the classical lock-on behavior found in experiments for similar flows is obtained. In addition, a novel method for eliminating the VIV response of the cylinder will be included.