Application of Advanced Vortex Method to Simulation of Self-Excited Vibration of a Circular Cylinder in Two-Dimensional Uniform Flow

An advanced vortex method with moving boundary condition is applied to the simulation of freely oscillating circular cylinder in a uniform flow at high Reynolds number in order to investigate validity and applicability to the analysis of the flow induced vibration problems. The motion of a circular cylinder is calculated from the motion of equation consisting of the damper c, mass m par unit length, natural frequency f_n and fluid force acting on the cylinder. The fluid force is evaluated by solving pressure-Poisson equation using the boundary element method. The calculation conditions are given as the Reynolds number Re (= U_∞D/v) = 10⁵, damper c/2πmf_n = 1.53 × 10⁻², natural frequency f_n/f_K = 0.5, 1.0, 2.0, 2.5, 3.0, mass ratio m/ρD = 5.15, where D, U_∞, ρ and f_K are the diameter of circular cylinder, reference velocity, density of the flow and the frequency of Karman vortex shedding from a fixed cylinder, respectively. The computational results, such as the flow pattern and motion of a circular cylinder, are in reasonable agreement with experimental results. It is confirmed that the advanced vortex method is useful to predict complex phenomena related to the flow-induced vibration problems.