Hybrid Analysis Method Using CFD And Analytical Solutions On Fluid Elastic Vibration Of Circular Cylinder Arrays
Free (open access)
K. Fujita & T. Wakita
In this paper, the hybrid method using the computational fluid dynamics (CFD) and the analytical solution on the fluid elastic vibration of circular cylinder arrays is proposed. The fluid forces acting on cylinder arrays are calculated as the influence coefficients which are obtained by the sinusoidal excitation on a cylinder in a small-scale of cylinder arrays subjected to a cross flow in the CFD simulation. Applying these fluid forces to a large-scale of cylinder arrays, the entire equations of motion can be derived for stability analysis. Comparing the direct simulation analysis based on CFD, the proposed hybrid method is found to be useful for evaluating the critical velocity of the fluid elastic vibration with less computational time. In addition, the present method is also very convenient for grasping the physical meaning on the fluid elastic vibration behavior, such as evaluating which vibration mode becomes unstable fastest among a group of complex eigenvalues generated by the coupled vibration among many circular cylinders in a fluid. Keywords: fluid elastic vibration, circular cylinder arrays, cross flow induced vibration, CFD simulation, stability analysis. 1 Introduction Many studies have been already performed on the mechanism of the fluid elastic vibration of circular cylinder arrays occurred in heat exchangers and stream generators, experimentally and analytically. Conners, Hartlen, Gorman, Zdravkovich, S. S. Chen and Ishigai et al. can be listed up first as the contributors
fluid elastic vibration, circular cylinder arrays, cross flow induced vibration, CFD simulation, stability analysis.