方柱绕流对污染物扩散影响的试验

An experiment on effect of flow past square cylinder on pollutant dispersion

建立透光率-COD浓度-污染物浓度三者之间的关系,通过试验初步研究了方柱绕流对污染物扩散的影响,试验结果表明:1)方柱绕流情况下,污染物纵、横向扩散均受到影响,横向扩散强度减缓,纵向扩散在方柱上游受到阻滞,扩散强度减小,下游受尾迹影响、旋涡的发展,扩散运动加强(方柱中心线处变化最大);2)相同情况下,流量越大,方柱绕流对污染物扩散影响幅度越小;3)污染物扩散受方柱绕流影响变化规律与水流紊动强度受方柱绕流影响变化规律一致.

The effect of flow past square cylinder on pollutant dispersion is researched througth building a relationship among the transmittance, concentration of COD, and concentration of pollutant by experiment. The results show that： （a） The dispersion of pollutant in both longitudinal and lateral directions is affected. While the dispersing of the pollutant is blocked and the dispersion concentration decreases upstream the square cylinder; the diffusion motion downstream is enhanced due to the development of vortex. And the diffusion intensity in lateral direction is reduced. （b） The influence of the flow around square cylinder on pollutant dispersion becomes weaker as the flow rate increases. （c） The change laws of the pollutant dispersion and turbulence intensity of flow affected by flow around square agree well.