Annular extrudate swell of Newtonian fluids: Effects of compressibility and slip at the wall

Mitsoulis, E

dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T01:25:55Z
dc.date.available	2014-03-01T01:25:55Z
dc.date.issued	2007	en
dc.identifier.issn	0098-2202	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17817
dc.subject	Annular flow	en
dc.subject	Blow molding	en
dc.subject	Exit correction	en
dc.subject	Extrudate swell	en
dc.subject	Linear law	en
dc.subject	Newtonian fluid	en
dc.subject	Pipe extrusion	en
dc.subject	Wall slip	en
dc.subject	Weak compressibility	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.other	Blow molding	en
dc.subject.other	Compressibility	en
dc.subject.other	Extrusion	en
dc.subject.other	Finite element method	en
dc.subject.other	Wall flow	en
dc.subject.other	Annular flow	en
dc.subject.other	Dimensionless compressibility	en
dc.subject.other	Exit corrections	en
dc.subject.other	Extrudate swell	en
dc.subject.other	Linear law	en
dc.subject.other	Newtonian fluids	en
dc.subject.other	Pipe extrusions	en
dc.subject.other	Swell reduction	en
dc.subject.other	Wall slips	en
dc.subject.other	Weak compressibility	en
dc.subject.other	Newtonian liquids	en
dc.title	Annular extrudate swell of Newtonian fluids: Effects of compressibility and slip at the wall	en
heal.type	journalArticle	en
heal.identifier.primary	10.1115/1.2786491	en
heal.identifier.secondary	http://dx.doi.org/10.1115/1.2786491	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Numerical simulations have been undertaken for the benchmark problem of annular extrudate swell present in pipe extrusion and parison formation in blow molding. The effects of weak compressibility and slip at the wall are studied through simple linear laws. The finite element method is used to provide numerical results for different inner/outer diameter ratios K under steady-state conditions for Newtonian fluids. The present results provide the shape of the extrudate, and, in particular the thickness and diameter swells, as a function of the dimensionless compressibility and slip coefficients, B and B,l, respectively. The pressures from the simulations have been used to compute the excess pressure losses in the flow field (exit correction). Weak compressibility slightly affects the thickness swell (about 1% in the range of simulations 0 <= B <= 0.02) mainly by a swell reduction, while slip drastically reduces the swelling to 1-2% for obvious slip (B-s1 approximate to 1) and to 0 for perfect slip (B-s1 > 10). The exit correction increases with increasing compressibility levels and is highest for the tube (kappa=0) and lowest for the Slit (kappa=1). It decreases monotonically to 0 as the dimensionless slip coefficient reaches its asymptotic limit of perfect slip. All results are ordered with the diameter ratio K, between the limits of tube (kappa= 0) and slit (kappa= 1).	en
heal.publisher	ASME-AMER SOC MECHANICAL ENG	en
heal.journalName	Journal of Fluids Engineering, Transactions of the ASME	en
dc.identifier.doi	10.1115/1.2786491	en
dc.identifier.isi	ISI:000251654200003	en
dc.identifier.volume	129	en
dc.identifier.issue	11	en
dc.identifier.spage	1384	en
dc.identifier.epage	1393	en