Mechanical energy transfer and flow parameter effects for a cylinder in transverse oscillation

Abstract

This paper deals with the two-dimensional numerical simulation of low-Reynolds number flow past a circular cylinder forced to oscillate transverse to the main stream. The study concentrates on the investigation of mechanical energy transfer E between the fluid and a transversely oscillating cylinder. When E is negative the fluid works to dampen the cylinder oscillation. When E is positive, work is done on the cylinder by the fluid and can be a source of vortex-induced vibration (VIV) for free vibration cases. One object of this paper is to identify domains of Reynolds number, oscillation amplitude and frequency ratio (Re, Ay, f/St0) where the mechanical energy transfer is positive. Other objectives are to learn more about the behaviour of force coefficients in the phase space and to roughly determine the lock-in boundaries. Computations are carried out using an in-house code based on the finite difference method. The three-dimensional domain of (Re, Ay, f/St0) is computed for Re=100–180, Ay=0.1–1.0 and frequency ratios between 0.6 and 1.2. A comparison is made with results in the literature for mechanical energy transfer contours within the lock-in domain, with good agreement obtained.