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A novel unified wall slip model for P oiseuille flow of polymer melt in the circular tube
Author(s) -
Ren Zhong,
Huang Xingyuan,
Liu Hesheng
Publication year - 2016
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.24258
Subject(s) - slip (aerodynamics) , materials science , slip ratio , mechanics , hagen–poiseuille equation , boundary value problem , shear rate , volumetric flow rate , slip line field , flow (mathematics) , rheology , thermodynamics , composite material , shear (geology) , shear stress , physics , quantum mechanics
In this study, to better reflect the slip effect of Poiseuille flow for polymer melt extruded through a circular tube, a novel unified wall slip model and flow equation based on two phase fluid system were proposed via a purely phenomenological approach. According to the different combinations of boundary conditions and flow parameters, the novel slip model was transformed into other models, such as adsorption–desorption model, entanglement–disentanglement model, lubrication layer model, Z–W model, and no‐slip model. The numerical simulation based on computed fluid dynamics was performed to verify the feasibility of the novel slip model. In the simulations, the radial flow velocity profile, shear rate, and viscosity distribution were obtained for six different models. Moreover, the effect of different slip coefficient combinations for the novel slip model on the radial flow velocity, slip velocity, volumetric flow rate error, and viscosity distribution of melt were also investigated and discussed. Results showed that the novel unified slip model not only incorporated the characteristics of other five models above mentioned, but also well interpreted the reason of simultaneously occurring the sharkskin surface defect and gross melt fracture phenomenon when flow rate of melt was extremely large. POLYM. ENG. SCI., 56:328–341, 2016. © 2015 Society of Plastics Engineers