摘要
该文基于研制的复式阶梯岸坡立面二维扩散水槽实验装置,采用顶点排放,对2个不同尺寸的复式阶梯岸坡水槽,分别按格栅震荡频率n=15、20、40和60 r/min,进行了瞬时线源排放的扩散实验。运用图像采集与数字图像处理技术测量二维浓度场分布。分析了断面浓度场、水面和深度平均浓度分布。结果表明:水面和深度平均浓度沿横向随离岸距离的增大而递减,后者在阶梯处垂直减小,且两者数值在河漫滩和离阶梯稍远的主槽相当,在离阶梯较近的主槽段前者大于后者。水面与深度平均浓度分布等浓度线呈现带状区域。提出了采用深度累积浓度矩法估算横向扩散系数,为复杂岸坡二维扩散横向扩散系数的估算提供了新方法。
Vertical two-dimensional diffusive tanks of compound stepped bank were developed for the research on the diffusion of instantaneous line source discharge. The pollutant was discharged from the vertexes at 2 different sizes of compound stepped banks, respectively, according to the grid vibration frequencies, n=15, 20, 40 and 60 r/min. Two-dimensional concentration field was measured by image collection and digital image processing technology. The concentration field of section, water surface concentration distribution and depth-averaged concentration distribution are analyzed. The results show that both water surface and depth-averaged concentration decrease with the increase of transverse offshore distance and the latter decreases perpendicularly at the ladder, both values are almost equal in the floodplain and main channel of a little further from the ladder, and the former is larger than the latter in the main channel nearby the ladder. The isoconcentration contours of the water surface and depth-averaged concentration distribution appear zonal area. The moment method of depth cumulative concentration is proposed to estimate the transverse diffusion coefficient, which provides a new method for the estimation of transverse diffusion coefficient in two-dimensional diffusion of complex bank.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2018年第1期48-57,共10页
Chinese Journal of Hydrodynamics
基金
国家自然科学基金资助项目(51379097)~~
关键词
复式阶梯岸坡
数字图像处理
浓度分布
矩法
横向扩散系数
compound stepped bank
digital image processing
concentration distribution
moment method
transverse diffusion coefficient
