Simulation of viscoplastic flow past cylinders in tubes

Mitsoulis, E; Galazoulas, S

dc.contributor.author	Mitsoulis, E	en
dc.contributor.author	Galazoulas, S	en
dc.date.accessioned	2014-03-01T01:31:54Z
dc.date.available	2014-03-01T01:31:54Z
dc.date.issued	2009	en
dc.identifier.issn	0377-0257	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19974
dc.subject	Cessation of flow	en
dc.subject	Drag coefficient	en
dc.subject	Flow past cylinders	en
dc.subject	Herschel-Bulkley model	en
dc.subject	Viscoplasticity	en
dc.subject	Yield stress	en
dc.subject.classification	Mechanics	en
dc.subject.other	Aspect ratio	en
dc.subject.other	Circular cylinders	en
dc.subject.other	Disks (structural components)	en
dc.subject.other	Drag	en
dc.subject.other	Drag coefficient	en
dc.subject.other	Plasticity	en
dc.subject.other	Viscoplasticity	en
dc.subject.other	Viscosity	en
dc.subject.other	Yield stress	en
dc.subject.other	Bingham numbers	en
dc.subject.other	Cessation of flow	en
dc.subject.other	Drag flows	en
dc.subject.other	Experimental values	en
dc.subject.other	Finite elements	en
dc.subject.other	Flow past cylinders	en
dc.subject.other	Herschel-Bulkley model	en
dc.subject.other	Numerical simulations	en
dc.subject.other	Simulation results	en
dc.subject.other	Visco-plastic models	en
dc.subject.other	Viscoplastic flows	en
dc.subject.other	Viscoplastic fluids	en
dc.subject.other	Yielded/unyielded regions	en
dc.subject.other	Flow simulation	en
dc.title	Simulation of viscoplastic flow past cylinders in tubes	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jnnfm.2008.10.006	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jnnfm.2008.10.006	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	Drag flow past circular cylinders concentrically placed in a tube filled with viscoplastic fluids, obeying the Herschel-Bulkley model, is analyzed via numerical simulations with the finite element method. The purpose it to find limiting drag values for cessation of motion of the object in steady flow. Different aspect ratios have been Studied ranging from a disk to a long cylinder. For the simulations, the viscoplastic model is used with an appropriate modification proposed by Papanastasiou, which applies everywhere in the flow field in both yielded and practically unyielded regions. The extent and shape of yielded/unyielded regions are determined along with the drag coefficient for a wide range of Bingham numbers. The simulation results are compared with previous experimental values [L. Jossic, A. Magnin, AlChE J. 47 (2001) 2666-2672] for cessation of flow. They show that the values of the drag coefficient are lowest for the disk and highest for the long cylinder. Discrepancies are found and discussed between the simulations and the experiments, with the simulations providing lower values in the limit of very high Bingham numbers. (C) 2008 Elsevier B.V. All rights reserved	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Journal of Non-Newtonian Fluid Mechanics	en
dc.identifier.doi	10.1016/j.jnnfm.2008.10.006	en
dc.identifier.isi	ISI:000265317500015	en
dc.identifier.volume	158	en
dc.identifier.issue	1-3	en
dc.identifier.spage	132	en
dc.identifier.epage	141	en