Slip effects in HDPE flows

Ansari, M; Hatzikiriakos, SG; Mitsoulis, E

dc.contributor.author	Ansari, M	en
dc.contributor.author	Hatzikiriakos, SG	en
dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T02:14:38Z
dc.date.available	2014-03-01T02:14:38Z
dc.date.issued	2012	en
dc.identifier.issn	03770257	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/30074
dc.subject	Entrance pressure drop	en
dc.subject	HDPE melt	en
dc.subject	K-BKZ constitutive equation	en
dc.subject	Non-isothermal die flow	en
dc.subject	Slip effects	en
dc.subject	Viscoelasticity	en
dc.subject.other	Capillary dies	en
dc.subject.other	Effect of pressure	en
dc.subject.other	Excess pressure	en
dc.subject.other	Experimental data	en
dc.subject.other	L/D ratio	en
dc.subject.other	Nonisothermal	en
dc.subject.other	Pressure dependence	en
dc.subject.other	Relaxation modulus	en
dc.subject.other	Rheological characterization	en
dc.subject.other	Shear rates	en
dc.subject.other	Slip effects	en
dc.subject.other	Time-temperature	en
dc.subject.other	Viscous heating	en
dc.subject.other	Viscous models	en
dc.subject.other	Wall slip	en
dc.subject.other	Wall-slip effects	en
dc.subject.other	High density polyethylenes	en
dc.subject.other	Pressure drop	en
dc.subject.other	Vehicular tunnels	en
dc.subject.other	Viscoelasticity	en
dc.subject.other	Viscosity	en
dc.subject.other	Pressure effects	en
dc.title	Slip effects in HDPE flows	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jnnfm.2011.09.007	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jnnfm.2011.09.007	en
heal.publicationDate	2012	en
heal.abstract	The capillary flow of a high-density polyethylene (HDPE) melt was studied both experimentally and numerically. The excess pressure drop due to entry (entrance pressure drop), the compressibility, the effect of pressure and temperature on viscosity, and the slip effects on the capillary data analysis have been examined. Using a series of capillary dies having different diameters, D, and length-to-diameter L/. D ratios, a full rheological characterization has been carried out, and the experimental data have been fitted both with a viscous model (Cross) and a viscoelastic one (the Kaye-Bernstein, Kearsley, Zapas/Papanastasiou, Scriven, Macosko or K-BKZ/PSM model). Particular emphasis has been placed on the effects of wall slip (significant for HDPE). For the viscous model, the viscosity is a function of both temperature and pressure. For the viscoelastic K-BKZ model, the time-temperature shifting concept has been used for the non-isothermal calculations, while the time-pressure shifting concept has been used to shift the relaxation moduli for the pressure-dependence effect. It was found that only the viscoelastic simulations were capable of reproducing the experimental data well. On the other hand, viscous modeling underestimates the pressures drops, especially at the higher apparent shear rates and L/D ratios. It is concluded that wall slip effects are significant for HDPE flow, whereas viscous heating is not. © 2011 Elsevier B.V.	en
heal.journalName	Journal of Non-Newtonian Fluid Mechanics	en
dc.identifier.doi	10.1016/j.jnnfm.2011.09.007	en
dc.identifier.volume	167-168	en
dc.identifier.spage	18	en
dc.identifier.epage	29	en