直管束流固耦合振动的数值模拟

为了研究反应堆结构中的诸如燃料棒、蒸汽发生器和其它换热器传热管束等的流体-结构交互作用问题，利用有限体积法离散大涡模拟(large eddy simulation, LES)的流体控制方程，用有限元方法求解结构动力学方程，并结合动网格技术，建立三维流体诱发振动的数值模型，模拟直管束中流体的流动及结构振动，实现计算结构动力学(computational structure dynamics, CSD)与计算流体力学(computational fluid dynamics, CFD)之间的联合仿真．首先，基于流固耦合方法对单管的流致振动特性进行了详细分析，得到了其动力学响应与流场特性；其次基于建立的传热管束流致振动计算模型，研究了两并列管、两串列管以及3×3正方形排列管束的流致振动行为．

Numerical Simulation of Fluid-Structure Interaction for Tube Bundles

A numerical model for three-dimensional flow induced vibration was proposed. It was conducted in order to further improve the solution of fluid-structure interaction problems, occurring in the nuclear power field such as the behavior of PWR fuel rod, stream generators and other heat exchangers’tubes. A three-dimensional unsteady Navier-Stokes equation was computed with LES model. The numerical method was based on finite volume discretization large eddy simulation approach on structured grids combined with the technique of dynamic mesh. The model presented a three dimensional fully-coupled approach to solving simultaneously the fluid flow and the structure vibration, for the tube bundles in cross flows. The flow induced vibration characteristics of a single tube was first analyzed based on the FSI method. Both the dynamic response and flow characteristics were obtained. Secondly, the mutual influence of two tubes, either inline or parallel set was investigated based on the FIV numerical model for tube bundles. Finally, the flow induced vibration characteristics of 3×3 tube bundles were studied.