DENSITY CURRENTS AND SHEAR-INDUCED FLOCCULATION IN SEDIMENTATION TANKS

LYN, DA; STAMOU, AI; RODI, W

dc.contributor.author	LYN, DA	en
dc.contributor.author	STAMOU, AI	en
dc.contributor.author	RODI, W	en
dc.date.accessioned	2014-03-01T01:08:45Z
dc.date.available	2014-03-01T01:08:45Z
dc.date.issued	1992	en
dc.identifier.issn	0733-9429	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/10667
dc.subject.classification	Engineering, Civil	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.classification	Water Resources	en
dc.subject.other	FLOW	en
dc.subject.other	COAGULATION	en
dc.subject.other	SIMULATION	en
dc.title	DENSITY CURRENTS AND SHEAR-INDUCED FLOCCULATION IN SEDIMENTATION TANKS	en
heal.type	journalArticle	en
heal.identifier.primary	10.1061/(ASCE)0733-9429(1992)118:6(849)	en
heal.identifier.secondary	http://dx.doi.org/10.1061/(ASCE)0733-9429(1992)118:6(849)	en
heal.language	English	en
heal.publicationDate	1992	en
heal.abstract	A numerical model for the computation of turbulent flows in sedimentation tanks is presented. Based on a nonorthogonal grid formulation, it can handle fairly arbitrary two-dimensional geometrics. It solves the full two-dimensional elliptic governing flow equations with the k-epsilon turbulence model. Effects on momentum, as well as turbulent kinetic energy balances, due to sediment-induced density currents are taken into account. Solids with a broad settling velocity distribution are treated by considering different settling velocity classes. A simple flocculation model assuming only turbulent shear-induced flocculation is formulated, and the importance of this cause of flocculation is examined. Predicted velocity and concentration profiles and removal efficiencies are compared with observations in a tertiary settling basin in Sweden. Results suggest that the flow field is significantly changed by seemingly small density differences. that shear-induced flocculation is relatively unimportant, and that the influent settling velocity distribution is critical for accurately predicting of removal efficiencies.	en
heal.publisher	ASCE-AMER SOC CIVIL ENGINEERS	en
heal.journalName	JOURNAL OF HYDRAULIC ENGINEERING-ASCE	en
dc.identifier.doi	10.1061/(ASCE)0733-9429(1992)118:6(849)	en
dc.identifier.isi	ISI:A1992HV71200002	en
dc.identifier.volume	118	en
dc.identifier.issue	6	en
dc.identifier.spage	849	en
dc.identifier.epage	867	en