Correlations for zero-shear and shear-rate dependent viscosity of polymeric solutions

1977 ◽  
Vol 17 (11) ◽  
pp. 806-810
Author(s):  
B. Chitrangad ◽  
H. R. Osmers ◽  
S. Middleman
Keyword(s):  
Shear Rate ◽  
Rate Dependent ◽  
Polymeric Solutions ◽  
Dependent Viscosity

Thermo-elasto-hydrodynamic lubrication model for journal bearing including shear rate-dependent viscosity

10.1002/ls.45 ◽  
2007 ◽  
Vol 19 (4) ◽  
pp. 231-245 ◽  
Author(s):  
Saša Bukovnik ◽  
Günter Offner ◽  
Valdas Čaika ◽  
Hans H. Priebsch ◽  
Wilfried J. Bartz
Keyword(s):  
Shear Rate ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Rate Dependent ◽  
Dependent Viscosity

Surface Temperature and Heat Transfer Conditions in the Ablation of Shear Thinning and Shear Thickening Liquids

1969 ◽  
Vol 91 (1) ◽  
pp. 105-110
Author(s):  
B. Steverding
Keyword(s):  
Mass Transfer ◽  
Shear Rate ◽  
Heat And Mass Transfer ◽  
Shear Thickening ◽  
Nose Radius ◽  
Newtonian Viscosity ◽  
Rate Dependent ◽  
Viscosity Behavior ◽  
Newtonian Liquids ◽  
Dependent Viscosity

The heat and mass transfer conditions for the ablation of Newtonian liquids have been described in a number of excellent articles. However, little attention has been paid to the behavior of non-Newtonian liquids for which the viscosity is not only a function of temperature but also of shear rate. This is astonishing since many excellent ablators behave in a non-Newtonian manner, especially when they contain foreign particles such as gas bubbles. The purpose of this paper is to study changes in heat and mass transfer if the ablator has a shear rate dependent viscosity. As a result of this study it will be shown that deviations from normal Newtonian behavior increase with increasing shear stress and decreasing bluntness of the cone. Surface temperatures are calculated as a function of Mach number, degree of non-Newtonian viscosity parameter, nose radius, and altitude. Numerical results are given for a model substance with the physical characteristics of Pyrex glass but with a hypothetically varying degree of non-Newtonian viscosity behavior.

Application of the Quemada Viscosity Model for Drilling Fluids

2021 ◽  
Author(s):  
Sandra Knutsen ◽  
Eric Cayeux ◽  
Arild Saasen ◽  
Mahmoud Khalifeh
Keyword(s):  
Shear Rate ◽  
Yield Stress ◽  
Drilling Fluid ◽  
Model Fit ◽  
Drilling Fluids ◽  
Shear Rates ◽  
Rate Dependent ◽  
Dependent Viscosity ◽  
Very High

Abstract A number of different models are used to describe the shear rate dependent viscosity of drilling fluids. Most, such as the Herschel-Bulkley model, have a purely empirical basis. The Quemada model, while still empirical, is based on physical principles. It is based on the notion that structural units develop in the fluid at low shear rates which are then partially broken down as the applied shear rate increases. In the current work, drilling fluid rheological data are fitted to the Herschel-Bulkley and the Quemada model. The development of the Quemada model and the calculation of each model parameter are presented. We show that the Quemada model better fits measurements over a wider range of shear rates than the Herschel-Bulkley model. We describe how to select the parameters of the Quemada model. Knowing the difficulty of obtaining a known shear rate for fluids with yield stresses, we discuss how this can affect the quality of the Quemada model fit. Furthermore, in principle, the Quemada model is not applicable in presence a non-zero yield stress. Therefore, we show how to handle the yield stress using a (very high) zero shear rate viscosity.

scholarly journals Computational fluid dynamics analysis of a high-throughput viscous heater to process feces and a fecal simulant using temperature and shear rate-dependent viscosity model

2017 ◽  
Vol 8 (1) ◽  
pp. 27-32
Author(s):  
C. L. German ◽  
J. T. Podichetty ◽  
A. Muzhingi ◽  
B. Makununika ◽  
J. Smay ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Shear Rate ◽  
Operating Conditions ◽  
Rate Dependent ◽  
Annular Gap ◽  
Computational Fluid Dynamics Analysis ◽  
Fecal Sludge ◽  
Dependent Viscosity

Abstract Open defecation and poor fecal management facilitates the spread of disease. Viscous heating can pasteurize fecal sludge by creating a high shear field in the annular gap between a stationary, cylindrical outer shell and a rotating inner core. As sludge flows axially through the annular gap, thorough mixing and frictional heating eliminate cool spots where microbes may survive. A viscous heater (VH) compares favorably to a conventional heat exchanger, where cool slugs may occur. Computational fluid dynamics (CFD) was used to determine the effects of geometry and fluid rheology on VH performance over a range of conditions. A shear-rate and temperature-dependent rheological model was developed from experimental data, using a sludge simulant. CFD of an existing VH used the model to improve the original naïve design by including temperature and shear rate-dependent viscosity. CFD results were compared to experimental data at 132 and 200 L/hr to predict design and operating conditions for 1,000 L/hr. Subsequent experimentation with fecal sludge indicated that the CFD approach was valid for design and operation.

Sign in / Sign up

Export Citation Format

Share Document