半圆形粗糙元壁面颗粒沉积数值模拟研究

为研究半圆形粗糙元壁面对颗粒沉积的影响，分别采用雷诺应力模型（RSM）和离散相模型（DPM）求解流场与颗粒运动轨迹，并结合临界速度判别颗粒沉积的方法。通过构建不同半圆形粗糙元参数（e/D，p/e）的通风管道计算域，研究了1~10 μm颗粒沉积速度变化及沿气流方向颗粒的沉积趋势，分析了流场所引起的湍流变化对颗粒沉积的影响，与相同参数下的方形粗糙元壁面颗粒沉积特性进行了对比。同时，分析了粗糙元参数对颗粒沉积速度的影响。结果发现，半圆形壁面颗粒沉积速度小于同参数下的方形壁面颗粒沉积速度，这是由于半圆形壁面的回流区相对方形粗糙元更小，捕捉颗粒能力差，半圆形粗糙元流体附壁效应导致半圆形粗糙元拦截效率较低。当e/D=0.02，p/e=3时，颗粒沉积速度变化较大，但在其余参数下变化并不大。半圆形粗糙元壁面的迎风面是颗粒沉积的主要区域。

Numerical simulation of particle deposition in semicircular ribbed duct

In this study,the influences of rib spacing and height on particle deposition in semicircle ribbed duct air flows are numerically investigated,RSM and DPM are used to solve the flow field and particle trajectory respectively,and the critical velocity is used to identify particle deposition. Different semicircular rough element parameters (e/D,p/e) are designed to investigate particle deposition velocity. The result is also compared with that in square ribbed duct.It is found that particle deposition velocity in semicircle ribbed duct is lower than that in square ribbed duct with the same rough element parameters.This is because of that the recirculation zone of the semicircular ribbed wall is smaller than that of the square rough element,and the ability to capture particles is poor.At the same time,the semicircular rough element has a lower interception efficiency. Besides,the influence of rough element parameters on particle deposition velocity is also analyzed.The results show that the particle deposition rate changes greatly when e/D=0.02 and p/e=3,but does not change much under other parameters. Moreover,the windward surfaces are the main deposition regions.