面源模式的通用算法探讨  

A Discussion on the General Algorithm for Area-Source Air Pollution Dispersion Model

作　　者：吴文军[1] 丁峰[1] 

机构地区：[1]国家环境保护总局环境工程评估中心,北京100012

出　　处：《环境科学研究》2007年第2期118-122,共5页Research of Environmental Sciences

摘　　要：提出了矩形面源扩散模拟计算的数值积分法和中心虚点源法,以及二者结合的综合法,并用算例进行了计算精度、计算速度和结果连续性的对比.结果表明:与传统的后置虚点源法及其改进算法——谷清经验法相比,该算法与理论真值的相对误差可从20%以上降低到3%以下,并且可以准确地反映风向和面源的形状,但在计算量上要增大十几倍到上百倍.对于任意不规则面源,提出了正方形分割算法,并对分割正方形的取舍采用简便的重心判断法,以准确方便地模拟其形状.综合运用笔者提出的适于机算的通用面源算法,对不同的计算任务权衡速度和精度采用合适的算法,可以处理各种气象条件下任意形状面源的扩散计算,并可取得理想的计算精度.The digital-integral algorithm and central-fictive-point-source algorithm, along with their integrated algorithm were presented for rectangle shape area-source dispersion simulation. Using computing samples, the results of these algorithms were compared with those of traditional algorithm （including some other revised algorithm） in aspects of exactness, calculating speed and data consecutiveness. Compared with backward-fictive-point-souree algorithm and its revised version, the algorithms proposed here can reduce the relative error from above 20% to below 3%, and can reflect the shape of source and wind direction variations. It also brings square-split algorithm for irregular-shape area source, and gives a new convenient judgment of square-cell position-by its barycenter. With balanced considerations of computer speed and precise demand of actual project, the synthetic application of these methods provides a general and precise computer-based algorithm for any shape of area sources.

关 键 词：大气扩散 面源模式 计算方法 数值模拟 分割算法 不规则面源 

分 类 号：X169[环境科学与工程—环境科学]