Research On Impact Dynamics Analysis Method For Elastic Cylinder Bundles In Cylindrical Fluid

Elastic cylinder bundles in cylindrical fluid is a typical structure of many important equipments,such as rod bundle fuel assembly for reactor,evaporators,heat exchanger,etc.The design of the impact safety is related to many scientific and technical problems such as fluid-structure interaction,dynamic characteristics and impact dynamic response.Fuel assembly and the evaporator are important parts of nuclear power plant which is widely used in military power.Its impact safety is one of the main factors that determine the impact safety of the system.Once the impact damage occurs,it may have serious consequences.Therefore,dynamic analysis method of elastic cylinder bundles in cylindrical fluid has important practical value for the safety evaluation of military nuclear power plant and civilian equipment.For a long time,dynamic analysis method of elastic cylinder bundles in cylindrical fluid is mostly based on the engineering method.Little attention has been paid to the mechanism and law of fluid-structure interaction,which seriously affects the control of its dynamic characteristics.This paper starting with the mechanism and law of fluid-structure interaction explores the fluid-structure interaction and dynamic modeling method of the elastic cylinder bundles in cylindrical fluid,which lays a scientific foundation for the prediction and evaluation of the impact resistance.This paper carries out in three aspects which include theoretical calculation,numerical calculation and experiment.Firstly,the formula of the added mass is obtained based on the potential flow theory.Secondly,the model is analyzed by ANSYS.By comparing the results with the theoretical analysis results,the correctness of the theoretical formula is verified.Thirdly,the formula is verified by experiment whose model is designed on the basis of the calculation model.Experimental results show that the added mass decreases with the increase of the mode,the distance between the cylinder and the boundary and the distance between the cylinders.The vibration phase and the vibration direction of the cylinder have different influence on the added mass.This is consistent with the theoretical and numerical results.Finally,the added mass is applied to the DDAM,and the maximum response of the cylinder is in agreement with the experimental results.The calculation method and the law are proved to have good accuracy by experiment.They provide a good theoretical basis for the prediction and control of the impact dynamic characteristics of elastic cylinder bundles in cylindrical fluid.