MODELING OF BOGER FLUID JETS USING THE OLDROYD-B EQUATION - A COMPARISON OF EXPERIMENTAL AND NUMERICAL RESULTS

The adequacy or otherwise of the Oldroyd-B equation in describing the elongational behavior of viscoelastic fluids was tested by comparing the fully developed profile of gravity-drawn Boger fluid jets calculated from the theory against that observed in the laboratory. Comparison of finite element extrudate-swell results with the measured swell was also carried out. The Oldroyd-B equation was found to out perform the other equations investigated even though in all cases substantial discrepancies between experiment and numerical simulation were observed. Limitations of the current numerical work and experimental program are discussed.