Abstract
Mixing of non-Newtonian fluids is widely encountered in the process industries. In this research, we obtained a constitutive expression that relates the viscosity of a mixture of glycerol and a gel formed of polyethylene glycol and Carbomer to the shear rate, temperature and mass fraction of one of the two components. We found that the mixtures of these two fluids were well characterized by a non-Newtonian power law model. We then used a number of homogeneous mixtures of the two fluids at different temperatures and mass fractions in a simple stirred tank agitated mechanically by a Rushton turbine to derive experimental power curves, which we then derived numerically in a CFD model by replicating the experimental conditions. We used a combination of an air bearing and a load cell to precisely measure the power required by the impeller to agitate the non-Newtonian mixtures. The computational and experimental results are in good agreement, indicating that the rheological data and the CFD model are accurate.
Highlights
Mixing of non-Newtonian fluids is widely encountered in the process industries
These fluids are complex to mix, and often sophisticated impeller designs are required (Kresta et al, 2015; Chhabra and Richardson, 2011). This is the case in the oral health industry, where highly viscous non-Newtonian fluids are used in the Computational fluid dynamics (CFD) is a powerful tool that yields relevant process information and permits assessing the performance of stirred vessels
The results are in good agreement with the power curve suggested in the literature for mixing in geometrically similar systems equipped with a Rushton turbine
Summary
Mixing of non-Newtonian fluids is widely encountered in the process industries. In this research, we obtained a constitutive expression that relates the viscosity of a mixture of glycerol and a gel formed of polyethylene glycol and Carbomer to the shear rate, temperature and mass fraction of one of the two components. Even if non-Newtonian fluids are employed in many industrial processes, less information is available about them These fluids are complex to mix, and often sophisticated impeller designs are required (Kresta et al, 2015; Chhabra and Richardson, 2011). This is the case in the oral health industry, where highly viscous non-Newtonian fluids are used in the Computational fluid dynamics (CFD) is a powerful tool that yields relevant process information and permits assessing the performance of stirred vessels. There are three main methods for validating CFD models: (i) power consumption of impellers, (ii) velocity profiles and (iii) change of properties over time These are briefly reviewed below for non-Newtonian fluid mixing. Where p is the fluid dynamic pressure, I is the identity tensor and is the deviatoric (i.e., the traceless) stress tensor of the fluid
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
