纳米粒子在弯管中的输运和沉降特性

Prediction of Nanoparticle Transport and Deposition in Bends

用摄动法对不同Reynolds数和Schmidt数的纳米粒子在圆截面弯管中的运输和沉积进行了求解.结果表明,当悬浮纳米粒子在直管中流动时,粒子输运模式不依赖于粒子的大小和其它参数.在弯管中运动时,管道外弯侧具有最多的沉积粒子而内弯侧的沉积粒子最少.在管道的上部和下部,不同Schmidt数粒子的沉降特性一致.管道曲率、Reynolds数和Schmidt数对粒子相对沉积效率的影响具有二阶,四阶和一阶的作用.

Nanoparticle transport and deposition in bends with circular cross-section were solved for different Reynolds number and Schmidt number. The perturbation method was used to solve the equations. The results show that the particle transport patterns are similar and not dependent on the particle size and other parameters when suspended nanoparticles are flowing in the straight tube. Particle deposition at the outside edge is most intensive, and oppositely, the deposition at the inside edge is the weakest. At the upper and lower tube, the depositions are approximately the same for different Schmidt number. Curvaages of tube, Reynolds number and Schmidt number have effects of second order, fourth order and first order on the relative deposition efficiency, respectively.