ISSN:0148-6055    

DOI:10.1122/1.549985

出版商:The Society of Rheology    

年代:1988

数据来源: AIP

摘要:

The K‐BKZ constitutive model is now 25 years old. The article reviews the connections of the model and its variants with continuum mechanics, molecular theory, and experiment. An application of this type of model to computation is mentioned.

ISSN:0148-6055    

DOI:10.1122/1.549986

出版商:The Society of Rheology    

年代:1988

数据来源: AIP

摘要:

A fundamental investigation of the influence of particulate and matrix properties on the shear viscosity, primary normal stress coefficient, dynamic viscosity, and storage modulus of composite systems was undertaken. As expected, all four rheological properties were observed to increase upon addition of solid particulates and some of the composite systems exhibited a yield stress. The present research showed that a new equation obtained by a phenomenological modification of the Tanaka and White model allowed thea prioriprediction of suspension viscosity for shear‐thinning systems as a function of matrix properties, volume fraction of particulates, and shear rate. It also provided the flexibility of describing suspension viscosity of systems exhibiting an apparent yield stress. Investigation of the other rheological properties showed that a form of the Kitano et al. expression could describe the relative primary normal stress coefficient and the relative storage modulus; whereas, a form of the Chong et al. expression could describe the relative dynamic viscosity of the various composite systems.

ISSN:0148-6055    

DOI:10.1122/1.549987

出版商:The Society of Rheology    

年代:1988

数据来源: AIP

摘要:

This article presents the results of a study of the mechanisms that account for the pseudoplastic behavior of a concentrated suspension of noncolloidal particles. Specifically, the measured flow behavior index of the suspension is correlated with the calculated Hamaker constant for interparticular van der Waals attraction. As the interparticular attraction increases, the number of aggregated particles increases. In turn, the number of aggregated particles decreases as the shear rate increases. As a result, unless the interparticular attraction is negligible, the concentrated suspension is pseudoplastic at low and moderate shear rates, but becomes Newtonian at high shear rates when the hydrodynamic force predominates. The measured viscosities both for high shear Newtonian limits of polystyrene suspensions and for the Newtonian suspensions of glass beads in silicone oil are in excellent agreement with the predicted values of the rigid sphere model for colloidal suspensions. In addition, we found that while its flow behavior is only slightly affected by particle size, the relative viscosity of the concentrated suspension is substantially affected by particle size, and correlates with the particle Peclet number.

ISSN:0148-6055    

DOI:10.1122/1.549988

出版商:The Society of Rheology    

年代:1988

数据来源: AIP