失水事故引起反应堆堆内结构动响应分析的声学有限元方法

Acoustic finite element method for dynamic response analysis of reactor internals induced by loss-of-coolant accident

失水事故引起的反应堆堆内结构动响应是反应堆结构动力学的重要问题。现有的分析计算方法主要是基于计算流体动力学(Computation Fluid Dynamics,CFD)的单向/双向流固耦合分析方法,数值预测精度较高但计算成本过高。本文基于以流体和固体位移和流体压力为基本未知量的势流体声学有限元理论,采用商用有限元软件ADINA和流固界面共节点网格技术,对德国HDR(Heiss Dampf Reaktor)实验堆V32破口失水事故进行了数值模拟。声学有限元-结构耦合计算结果与文献中的实验测试结果和基于CFD的双向流固耦合结果吻合良好,但比CFD方法更易于实现且具有较高的计算效率。研究结果为反应堆失水事故下堆内结构动响应提供了一种简单而高效的分析方法。

[Background]Dynamic response of reactor internals due to loss-of-coolant accident(LOCA)is one of the main issues in structural dynamics of nuclear reactors.Current analysis methods mainly adopt computation fluid dynamics(CFD)based fluid-structure interaction approaches,which have high numerical accuracy but pay the price of high computational cost.[Purpose]This study aims to propose acoustic finite element method for dynamic analysis of reactor internals induced by loss-of-coolant accident.[Methods]Displacements of both fluid and structure and the pressure of fluid were taken as basic unknown variables in this flow acoustic finite element method.The commercial code,ADINA,together with conforming mesh along the fluid-structure interface,was utilized to model the V32 experiment of the Germany HDR(Heiss Dampf Reaktor)reactor.[Results]The acoustic-structure coupling results agree well with the experimental results reported in reference and the results given by CFD-based two-way coupling method whilst relative lower computation cost and ease implementation are achieved.[Conclusions]The study provides a straightforward and efficient method for engineering nuclear LOCA dynamic analysis.