Flow induced vibration model based on grid-free surface vorticity method

To investigate the cross flow induced vibration of heat exchanger tube bundles, a separation point determination model and a fluid-structure interaction model based on surface vorticity method are proposed. The flow around a rigid cylinder and the vibration of a flexible cylinder are simulated at Re = 2.67 × 10⁴, and the cylinder response, fluid force, vibration frequency, and vorticity map are presented. The simulation results reflect the main features of the flow around a rigid 2-D cylinder and reproduce the amplitude-limiting and nonlinear (lock-in) characteristics of flow-induced vibration. The calculated mean drag coefficient, rms lift coefficient, Strouhal frequency, and the maximum vibration amplitude as well as the corresponding lock-in frequency well coincide with the experimental results in the existing literatures. The proposed model is expected to provide a new method to evaluate the flow induced vibration of a large number of flexible tube bundles with a relatively simple computing task.