Computational rheology with integral constitutive equations

Mitsoulis, E

dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T11:45:42Z
dc.date.available	2014-03-01T11:45:42Z
dc.date.issued	1999	en
dc.identifier.issn	14306395	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/37572
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0033398662&partnerID=40&md5=0e668e5a2f2d1e3bcbd49c0310ba9b73	en
dc.subject	Computational rheology	en
dc.subject	Integral constitutive equations	en
dc.subject	Viscoelasticity	en
dc.subject.other	computational fluid dynamics	en
dc.subject.other	drag coefficient	en
dc.subject.other	finite element analysis	en
dc.subject.other	polymer	en
dc.subject.other	rheology	en
dc.subject.other	streamline (flow)	en
dc.subject.other	viscoelasticity	en
dc.subject.other	vortex	en
dc.title	Computational rheology with integral constitutive equations	en
heal.type	other	en
heal.publicationDate	1999	en
heal.abstract	Computational rheology deals with the formulation and solution of constitutive equations for non-Newtonian materials. From these the emphasis is put on polymeric materials, which exhibit both viscous and elastic behaviour in flow and deformation. These materials are often called viscoelastic materials. Polymer solutions and melts (e.g. commercial plastics and rubber) are good examples of viscoelastic materials. Their processing under continuous (e.g. extrusion) or batch (e.g. injection molding) operations is the main occupation of the plastics and rubber industries, but the corresponding modelling and numerical simulation is a difficult task and a relatively recent undertaking. The present work reviews modelling aspects of viscoelasticity and shows how the complex rheology of these materials is best captured through integral constitutive equations with a spectrum of relaxation times. Using such constitutive equations and the Finite Element Method (FEM), the solution of some benchmark problems of rheology becomes feasible. Examples will be shown from the flow of polymer melts and solutions in a 4:1 axisymmetric contraction encountered in standard capillary rheometry, as well as the flow around a sphere falling in a cylindrical tube. The emphasis will be on demonstrating the flow patterns via streamlines and predicting such viscoelastic phenomena as vortex growth, extrudate swell, and reduction of the drag coefficient, which are of particular interest to the rheological community as test cases of computational results.	en
heal.journalName	Applied Rheology	en
dc.identifier.volume	9	en
dc.identifier.issue	5	en
dc.identifier.spage	198	en
dc.identifier.epage	203	en