垂直摇臂式喷头导流器的流固耦合分析

Fluid- structure interaction analysis of deflector in vertical sprinkler

以垂直摇臂式喷头的导流器为研究对象,对导流器从水射流中获取的驱动力进行理论分析和试验测量.基于流固耦合原理,初步建立了垂直摇臂式喷头导流器驱动力数值模拟计算模型,并通过试验结果验证数值模拟结果的准确性.将流场计算结果加载到导流器固体域上,对导流器进行了力学分析和模态分析.结果表明:模拟得到的导流器从水射流中获取的驱动力值与试验值的最大偏差为15.98%,但随着压力的升高,偏差值逐渐降低;通过力学分析得到导流器在受水射流冲击时的变形主要分布在弯曲叶片部分;通过有限元模态分析,得到导流器前6阶模态的固有频率和振形,当导流器的工作频率小于122.6 Hz时,其振动以一阶振形为主.为了提高导流器的工作稳定性与可靠性,可以通过改进局部结构或提高材料的力学性能实现.

Taking the deflector of a vertical sprinkler as a study model, the driving force applied on the deflector by the water jet is analyzed and measured. Based on the fluid - structure interaction principle, a numerical model for describing the driving force is built initially and validated by the experimen- tal results. The fluid pressure profile obtained from a flow field simulation is imposed onto the deflec- tor, then solid mechanics and free vibration analyses are carried out on it. The results show that the maximum error in the horizontal and vertical components of the driving force between simulation and experiment is 15.98%, which reduces with the increasing pressure. The maximum deformation is mainly distributed in the much curved part of the deflector. Eventually, the 1 st through 6th order natu- ral frequencies and corresponding vibration modes are obtained. When the deflector works under the frequency of less than 122.6 Hz, its vibration mode is usually in the first order. In order to improve the stability and reliability of the deflector in operation, its local configuration may need to be redesigned or a material with even stronger strength is adopted.