Study on transportation and diffusion characteristics of contaminants at flow confluence
摘要
In order to analyze transportation and diffusion characteristics of contaminants at flow confluence,this paper presents the results of a series of experiments that were conducted and the numerical simulation study for probing distribution rules at flow confluence.A two-phase flow model applicable to confluences was established,and it was verified by experimental results.Experiments and numerical simulation were performed for different conditions.The results indicate that: A long and narrow contaminated zone is formed near the tributary side;and,the smaller junction angle and flow ratio(momentum ratio) are narrower with contaminated zone;within the contaminated zone,the gradient of concentration is great;and,contaminants distribution at the confluence is mainly determined by the effects of transportation and diffusion.These study results can provide a scientific basis for environmental evaluation,management and pollution control of river confluence.