ISSN:
1435-1528
Schlagwort(e):
Bagley correction
;
end effects
;
K-BKZ equation
;
integral constitutive model
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Abstract The excess pressure losses due to end effects in the capillary flow of a linear low-density polyethylene resin (LLDPE) were studied both experimentally and numerically. First, they were determined experimentally by using two methods: i) by extrapolating experimental data of pressure drop versus length-to-radius ratios (L/R) to zero capillary length and ii) by means of using orifice dies (L/R ≈ 0). Both methods resulted in about the same end corrections. Numerical simulation was also used to model this important aspect of experimental rheology. The constitutive equation used in the simulations is a multimode K-BKZ equation proposed by Papanastasiou et al. (1983, J. Rheol. 27:387) and further modified by Luo and Tanner (1988, Int. J. Num. Meth. Eng., 25:9). It was found that the numerical predictions agreed qualitatively, but underestimated the experimental data for the various geometries used to determine the end effects.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00396506
