Periodic vortex shedding from a bluff body placed in flow induces periodic forces acting on the body (for example, smokestacks, silos, underwater pipes or tube bundles of heat exchangers), which has the potential to cause vibration, leading to fatigue or even damage of the structure. This talk introduces results from numerical simulations of flow around circular cylinders oscillating in a variety of ways that occur in real life: transverse motion, in-line (streamwise) motion, or following an elliptical or figure-eight path.
The presentation will show the differences between the force coefficients for the different cylinder paths, as well as the energy transfer between the fluid and cylinder. When plotting the results against some parameters often sudden changes can be found, which usually refers to a sudden change in the vortex structure. Pre- and post-jump analysis is applied in the vicinity of these points in the forms of limit cycles, time history curves, and vorticity contours. Special emphasis is placed on the mechanical energy transfer between the fluid and cylinder, which can be an indicator of the potential risk of vortex-induced vibration.
The research was performed using a finite difference based two-dimensional in-house code developed by the author.
Prof. Baranyi works at the Department of Fluid and Heat Engineering at the University of Miskolc (Hungary). He lectures primarily on fluid mechanics, heat transfer, and computational fluid dynamics. His field of research centers on fluid-structure interaction and numerical simulation. He spent two years as a visiting professor at Nagaoka University of Technology (Japan), and has given talks at universities around Europe. He is an editor of the Journal of Computational and Applied Mechanics, a regular reviewer for several leading journals, and a regular co-developer of sessions of the ASME Pressure Vessels and Piping conferences.