非牛顿流体滩涂钢板桩围堰泄漏量分析

Analysis on leakage of steel sheet cofferdam in mud flat of non-Newtonian flow

以非牛顿流体淤泥为介质,采用ANSYS Fluent软件,对滩涂埋地管道抢修围堰不同位置的泄漏量进行研究,得到稠度系数、幂律指数、缝隙尺寸对围堰泄漏量的影响规律,并对围堰内部淤泥每小时上升高度进行了计算。结果表明:幂律指数小于1时,发生剪切稀化,淤泥表观黏度随剪切应变率的增加而降低;随着幂律指数的增大,泄漏量逐渐增加,淤泥表观黏度随幂律指数的增大而降低,尤其是幂律指数大于1时,泄漏量进一步增加,说明流体流动过程中剪切应变率小于1。稠度系数增大时,围堰的泄漏量逐渐降低;缝隙尺寸增加时,围堰的泄漏量显著增大。当幂律指数为0.3~0.5、稠度系数为3~9 kPa·s、缝隙尺寸为5~10 mm时,围堰内部淤泥上升的总高度对围堰内部施工影响很小。

Taking the mud as non-Newtonian fluid,the leakage of the cofferdam in different positions for emergency repair of buried pipeline in mud flat was studied using ANSYS Fluent software.The influence of non-Newtonian consistency coefficient,power law index,and gap size on leakage was discussed,and the hourly rise of mud in the cofferdam was calculated.The results indicate that when the power law index is less than 1,shear thinning occurs,and the apparent viscosity of mud decreases with the increase in shear strain rate.With the increase in power law index,the leakage increases gradually,indicating that the apparent viscosity decreases with the increase in power law index.Moreover,when the power law index is greater than 1,the leakage increases further,indicating that the shear strain rate is less than 1 during flow process.The leakage of the cofferdam decreases gradually with the increase in consistency coefficient,but increases significantly with the increase in gap size.When the power law index is in the range of 0.3 to 0.5,the consistency coefficient is in the range of 3 to 9 kPa·s,and the gap size is in the range of 5 to 10 mm,the total height of the mud rising inside the cofferdam has little effect on the construction inside the cofferdam.