表面粗糙度对金属平垫泄漏率的影响

Effect of Surface Roughness on Leakage Rate of Metal Flat Pad

为探究金属垫片表面形貌对泄漏率的影响,通过三维形貌仪对不同表面粗糙度的Cu、Al和316L金属垫片进行局部扫描,构建出真实法兰垫片的微观接触模型。在此基础上,进行静力学和计算流体力学分析,通过对流体域设置不同的边界条件,考察不同介质压力下,表面粗糙度和接触压力对泄漏率的影响。仿真结果表明:3种材质的垫片均呈现表面粗糙度越大,则泄漏率越大的趋势;其中,Al垫片的泄漏率对表面粗糙度最为敏感,316L垫片的泄漏率受表面粗糙度的影响最小;当表面粗糙度一定时,施加的接触压力越大,泄漏率越低,但当接触压力达到一定值后,增大接触压力对降低泄漏率的影响将越来越小。

To investigate the effect of surface morphology of metal gaskets on leakage rate,the local scanning of Cu,Al and 316L metal gaskets with different surface roughness was carried out by 3D morphometer,and the real microscopic contact model of flange gaskets was constructed.The statics and computational fluid dynamics analysis was carried out to investigate the influence of surface roughness and contact pressure on the leakage rate under different medium pressure by setting different boundary conditions in the fluid domain.The simulation results show that the metal gaskets of three materials exhibit a trend of greater surface roughness leading to greater leakage rate.Among them,the leakage rate of Al gasket is the most sensitive to surface roughness,while the leakage rate of 316L gasket is the least affected by surface roughness.When the surface roughness is constant,the greater the applied contact pressure,the lower the leakage rate.However,when the contact pressure reaches a certain value,the effect of increasing the contact pressure on reducing the leakage rate will become smaller and smaller.