Numerical simulation of flow past stationary and oscillating deformable circles with fluid-structure interaction

The oscillation and deformation of the tube affect its safe and efficient operation in the shell-and-tube heat exchanger of the nuclear power plant. To offer in-depth understandings, numerical simulation of the flow around the cylinder (or particle) was carried out here by using COMSOL Multiphysics as a research tool. This paper mainly discusses the influence of physical parameters (elastic modulus and Poisson’s ratio) and lateral oscillation on the flow around the circles (cylinder or particle). The physical property parameters have a greater influence on the deformation, lift coefficient, and drag coefficient of the object, and it basically does not affect the vortex shedding frequency. After analyzing the flow around the oscillating particle, four kinds of vortex separation modes (AI, AII, S, S-S modes) are defined. In addition, the lift coefficient and drag coefficient for different modes are discussed. The phenomenon of "frequency locking" occurs in the flow around the oscillating particle. Simulation results prove that the separation frequency of vortex is related to the oscillation frequency.