Lift-Oscillator Model of Vortex-Induced Vibration

The main feature is the representation of fluctuating lift behavior in terms of a proposed wake-oscillator. The primary purpose of the paper is to demonstrate the potential of the wake-oscillator concept for future studies. The elastically mounted cylinder is modeled as a second-order, linear, damped system. The aerodynamic lift force is proportional to the instantaneous value of a fluctuating lift coefficient. The instantaneous lift coefficient is derived from the response of a proposed lift-oscillator, whose characteristics are deduced from existing experimental data. This oscillator is self-excited, its natural frequency is proportional to wind speed, and it is subjected to a coupling term proportional to the transverse cylinder velocity.