基于CFD的蝶板结构改进设计及数值分析

Butterfly disc structure improved design and numerical analysis based on CFD

为研究蝶阀阀板结构对阀门气蚀系数和流阻系数及阀门内部流动特性的影响,基于有限体积法和标准k-ε湍流模型,在不同开度(蝶板转角)下对梳齿形和楔形2种结构蝶板的蝶阀进行定常流动的三维数值模拟计算,获得阀门内部流场的速度场和压力场.比较分析阀门在不同工况下流道内部的速度分布、压力分布、速度流线图,得到速度对涡流形成及扩展的影响.结果表明:楔形蝶板的阀门流动更加平稳,在较大开度时流阻系数减小,流体对阀体和流道的冲击降低,蝶阀的流通能力提高;楔形蝶板阀的气蚀系数较梳齿形蝶板阀有所增大,抗气蚀的性能增强.研究结果为分析阀门内部受冲击状况提供了依据,为阀门优化设计提供了一定的借鉴.

In order to analyze the effects of butterfly valve disc structure on the valve cavitation coefficient,flow resistance coefficient and the internal flow characteristics,based on finite volume method and standard k-ε turbulence model,at different opening degrees（rotation angle of valve plate）,three-dimensional steady numerical simulation calculation of butterfly valves of comb-type and wedge-type structure discs was carried out.Velocity distribution,pressure distribution and velocity flow chart of the valves under different working conditions were compared and analyzed.The effects of velocity on the formation and expansion of the vortex was obtained.The results show that the fluid in wedge-type disc butterfly valve flows more smoothly,and the flow resistance coefficient of the valve decreases at larger opening.Therefore,it reduces the impact of flow on the valve body and passage and improves flow circulation.The cavitation coefficient of wedge-type disc butterfly valve is bigger than that of comb-type disc and the anti-cavitation performance is enhanced.The study provides a basis for analyzing the impact conditions inside the valve and can be useful in optimizing valve design.