反应堆堆内构件流体激振力的数值模型研究

针对反应堆堆内构件流致振动分析评价中如何合理获取流体激振力的关键技术难题,开展了典型反应堆堆内构件三维流场分析的数值模型研究.研究基于计算流体动力学方法,首先,根据反应堆堆内构件的结构特点和运行工况参数,将实际结构的关键部件、物理边界提取并做适当简化,在合理降低计算规模的同时,又充分保留其流场特征;其次,综合考虑计算资...

Numerical Model of Fluid Induced Vibration Force of Reactor Internals

Aiming at difficulty in obtaining fluid exciting force in the flow induced vibration analysis and evaluation of reactor internals, the numerical model of three-dimensional flow field analysis of typical reactor internals is studied based on computational fluid dynamics (CFD). Firstly, according to the structural characteristics and operating parameters of reactor internals, the key components and physical boundaries of the actual structure are extracted and simplified, so as to reduce the calculation scale reasonably and retain the flow field characteristics. Secondly, considering the computational resources and efficiency, the hybrid grid generation method of structural grid and unstructured grid and the partition grid size strategy are adopted. In order to capture the characteristics of the flow field, porous media is used to simulate the core section with complex flow field but not paying attention to its details, and then a three-dimensional flow field analysis model suitable for engineering is established. Three turbulence models with good prediction results are compared. The three-dimensional streamline and pressure distribution characteristics of reactor internals, the time history and PSD characteristics of pressure fluctuation at typical monitoring points, the prediction of fluid excitation forces of reactor internals by three turbulence models, and the characteristics of fluid exciting force acting on the surface of the core barrel are obtained. The results show that LES model can predict the fluid induced vibration forces of reactor internals, and has a certain conservatism. The fluid induced vibration forces acting on reactor internals conform to the wide-band and randomness. It can provide key parameters and input loads for flow induced vibration analysis and evaluation of reactor internals.