Author(s): Amy Jones; Ian Guymer; Virginia Stovin
Linked Author(s): Ian Guymer
Keywords: Manhole; Solute; Mixing; Partially-Full; Shallow Flows; Residence Time Distribution
Abstract: Manholes influence pollutant transport through sewers. It has been shown that solute transport across unbenched, surcharged manholes depends on the depth of water in the manhole: at low water depths solutes become well-mixed within the manhole, but at high depths most solute shortcircuits the manhole (Guymer et al., 2005). Stovin et al. (2010a) and Guymer and Stovin (2011) suggested that just two normalised Cumulative Residence Time Distributions (CRTDs) could be used to model solute transport across unbenched manholes of a particular geometry–one for low and one for high surcharges. However, their CRTD models were developed for surcharged conditions only, and partially-full pipe flow is more common in sewers (Butler and Davies, 2011). New dye visualization is presented which suggests that the flow regime under partially-full pipe conditions is distinct from that observed under any surcharged condition. CRTDs from partially-full pipe conditions are examined and compared with those for surcharged flows. Very low surcharges are also studied for the first time, giving further insight into the flow field within unbenched manholes under surcharged conditions.
Year: 2012