弯曲性分叉河道中污染物扩散性的初步研究

弯曲性分叉河道中水流特征复杂,对污染物扩散有很大影响。为了定量分析其水流特征对污染物扩散的影响,采用有限元方法求解弯曲性分叉河道中的污染物扩散数学模型,研究其中污染物扩散的状况。主要针对河道回流、绕流对污染物扩散的影响进行了详细数值模拟计算,并分别给出了可视化结果及平均的扩散距离。计算结果表明:边界层稍微减弱污染物的扩散,弯道分离使污染物扩散呈现多向扩散,而回流和绕流尾迹区使污染物很难扩散,从而有利于泄漏污染物的收集和集中治理。

Primary study on diffusion of contaminants in meandering furcated rivers

The flow characteristics in meandering furcated rivers are complicated and have great influence on the diffusion of contaminants.In order to analyze the influence quantitatively,the mathematical model for diffusion of contaminants was solved by finite element method.The influences of circumfluence and back flow on the diffusion of contaminants were simulated and calculated in detail,and the visual result and averaged diffusion distance were obtained.The results include that the boundary layer can alleviate the diffusion a little,the separation of the bends make the contaminants diffuse in multi-direction,and contaminants are difficult to diffuse in circumfluence and wake of back,which are good for the collection and concentrated control of contaminants.