【摘要】 为了获得污水管网非恒定流模拟精度要求的节点流量过程线,应用分形理论对污水流量序列的变化特性进行研究,并初步分析其中是否存在分形特征.首先,应用延迟时间法(G-P法)重构污水流量序列的相空间,计算关联维数;然后对北京市2个污水处理厂日进厂流量记录进行了研究.为了得到可靠的关联维数,分别研究了时间滞时τ=△t和τ=4△t 2种情况.研究结果表明:①污水流量序列中存在分形特性;②τ=△t时,lnC(r,M)～ln r曲线存在明显的直线段,能够估计到饱和时的关联维数:0.49(污水厂A)和0.53(污水厂B);③τ=4△t时,lnC(r,m)～ln r曲线也存在较为明显的直线段,关联维数为0.75(污水厂A)和0.44(污水厂B);④2个污水流量序列的关联维数定量地说明污水厂流量来源较单一.更多还原

【Abstract】 In order to obtain the nodal hydrograph suitable for the unsteady flow simulation of urban sanitary sewer networks, the study on the dynamic characteristics of sewage flow series is conducted using fractal theory so as to judge whether there are fractal traits. Firstly, the delayed-time method is used to reconstruct the phase space of sewage flow series and calculate the correlative dimension. Then case studies are carried out based on the daily flow records derived from two wastewater treatment plants (WWTPs) in Beijing. In addition, the correlative dimensions are calculated respectively according to the delayed-time τ =Δt and τ = 4Δt. The results indicate that (1) the fractal traits exist in sanitary flow series; (2) the distinct linear section occurs within ln C(r, m) - ln r curv.es and the correlative dimension is 0.49 for WWTP A and 0.53 for WWTP B when τ= Δt;(3) the distinct linear section also occurs in ln C(r, m) - ln r curves whenτ = 4 Δt and the correlative dimension is 0.75 for WWTP A and 0.44 for WWTP B;(4) the correlative dimensions of the flow series quantitatively show that the flow source of WWTP is simplex.更多还原