Fluid-solid Coupling Analysis And Optimization Design Of Butterfly Valve

As a kind of pressure piping element,valve is widely used in various fields of production and life.With the continuous development of CAE technology,numerical simulation is used to replace the traditional empirical formula and engineering test.Numerical simulation greatly improves the research and development efficiency,saves a lot of research and development costs,and has certain economic benefits.In this paper,DN150 butterfly valve in the gas supply pipeline is taken as the research object,and the following aspects are mainly studied:(1)The three-dimensional solid model of DN150 butterfly valve was established based on the fluid-solid coupling theory,and the Ansys Workbench software was used to conduct the grid division.Secondly,the internal flow field of the butterfly valve was analyzed based on Fluent software,and the pressure distribution diagram and streamline distribution diagram under different opening degrees were obtained.Finally,the flow field inside the butterfly valve and the valve body were analyzed by using Ansys Workbench,and the stress cloud diagram and deformation cloud diagram of the valve body under different opening degrees were obtained.The results show that when the opening of butterfly valve is less than 40 degrees,the change of flow velocity is obvious,the pressure on the valve body varies greatly,and the impact on the butterfly plate is greater.With the further increase of butterfly valve opening,the change of flow field tends to be stable.The analysis results provide a basis for the further design and optimization of valve.(2)By establishing the finite element numerical analysis model of butterfly valve sealing structure,defining the contact pairs,setting the constraints and adding loads,the pretreatment of the contact analysis was completed;The butterfly valve stress and total deformation cloud diagram were calculated,and the analysis showed that the maximum stress of butterfly valve appeared at the junction of stem and seal ring,and the stress and deformation were obvious at the connection position of stem and butterfly plate.According to the contact stress cloud diagram of the sealing surface,the minimum stress is located at the intersection of the valve stem and the sealing ring,and the minimum value is 5.212 MPa,which is larger than the required specific pressure of sealing,and the sealing performance is good.(3)Based on multi-objective genetic algorithm,parametric optimization design of butterfly valve is carried out.The sensitivity of the design variables to the objective function is obtained through the experimental design and response surface calculation,and the comparative analysis is carried out.Three optimal design points are obtained by using multi-objective genetic algorithm,and the data given by the design points are rounded.The optimized butterfly valve model is obtained and verified by static analysis.The result of optimization reduces the total mass of butterfly valve by 10.501% on the basis of guaranteeing its strength and stiffness.The lightweight design of the valve is realized.