Elongational flow behavior of viscoelastic liquids: Modelling bubble dynamics with viscoelastic constitutive relations

1978 ◽  
Vol 17 (5) ◽  
pp. 500-510 ◽  
Author(s):  
G. Pearson ◽  
S. Middleman
Keyword(s):  
Bubble Dynamics ◽  
Flow Behavior ◽  
Constitutive Relations ◽  
Elongational Flow ◽  
Viscoelastic Liquids

Elongational flow behavior of viscoelastic liquids: Part I. Modeling of bubble collapse

AIChE Journal ◽  
1977 ◽  
Vol 23 (5) ◽  
pp. 714-722 ◽  
Author(s):  
Glen Pearson ◽  
Stanley Middleman
Keyword(s):  
Flow Behavior ◽  
Elongational Flow ◽  
Bubble Collapse ◽  
Viscoelastic Liquids

Simulation of bubble growth and collapse in linear and pom-pom polymers

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Uday S. Agarwal
Keyword(s):  
Bubble Growth ◽  
Bubble Dynamics ◽  
Polymer Melt ◽  
Integral Form ◽  
Polymer Chains ◽  
Bubble Collapse ◽  
Flow Strength ◽  
Branch Lengths ◽  
Programming Effort ◽  
Viscoelastic Liquids

AbstractExisting approaches to simulate the bubble growth/collapse in viscoelastic liquids use the integral form of a constitutive equation, that can additionally be analytically integrated over the radial domain. Here we represent the process by a system of simultaneous partial differential equations, with fixed and finite boundaries. This enables a direct computer implementation with commercially available software, with little additional programming effort. The involved co-ordinate transformation preferably does not correspond to the material co-ordinates. The surrounding liquid can be simulated as being a finite film or of infinite extent, with simply a change in one computational parameter. We simulate hydrodynamically induced bubble dynamics in viscolelastic liquids, and estimate the flow strength (elongational strain rate) and its possible role in flow induced scission of polymer chains in liquids experiencing bubble collapse. Calculations are also performed to evaluate the influence of backbone and branch lengths when the surrounding fluid is a branched polymer melt, using the pom-pom model to describe the rheological behavior.

Shear and elongational flow behavior of acrylic thickener solutions. Part II: effect of gel content

2008 ◽  
Vol 48 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Saeid Kheirandish ◽  
Ilshat Gubaydullin ◽  
Norbert Willenbacher
Keyword(s):  
Flow Behavior ◽  
Elongational Flow ◽  
Gel Content

Elongational Flow Behavior of Polymeric Fluids

1976 ◽  
Vol 14 (1) ◽  
pp. 107-153 ◽  
Author(s):  
Jack W. Hill ◽  
John a. Cuculo
Keyword(s):  
Flow Behavior ◽  
Elongational Flow ◽  
Polymeric Fluids

scholarly journals A New Viscosity Constitutive Model for Generalized Newtonian Fluids Using Theory of Micropolar Continuum

2020 ◽  
pp. 120-134
Author(s):  
Muhammad Sabeel Khan
Keyword(s):  
Constitutive Model ◽  
Flow Behavior ◽  
Constitutive Relations ◽  
Shear Thickening ◽  
Blood Rheology ◽  
Newtonian Fluids ◽  
Model Parameters ◽  
Micropolar Continuum ◽  
Generalized Newtonian Fluids ◽  
Contour Plots

In this paper, a new viscosity constitutive relation for the analysis of generalized Newtonian fluids is presented and analyzed. The theory of micropolar continuum is considered for the derivation of constitutive relations where the kinematics at the macroscopic level leads to incorporate the micro-rotational effects in existing rheology of Carreau Yasuda model. It provides a more realistic approach to analyze the flow behavior of generalized Newtonian fluids. To the best of author’s knowledge such generalization of the existing rheology of Carreau-Yasuda is not present in literature. In order to show the effects of micro-rotations on the viscosity of generalized fluids, different computational experiments are performed using finite volume method (FVM). The method is implemented and validated for accuracy by comparison with existing literature in the limiting case through graphs and tables and a good agreement is achieved. It is observed that with the increase of micro-rotations the shear thinning phenomena slower down whereas the shear thickening is enhanced. Moreover, the effects of various model parameters on horizontal and vertical velocities as well as on boundary layer thickness are shown through graphs and contour plots It is worth mentioning that the proposed constitutive model can be utilized to analyze the generalized Newtonian fluids and has wider applications in blood rheology.

Scaling Behavior in Electrohydrodynamic Jetting of Polymeric Solutions

2019 ◽  
Author(s):  
Abhishek K. Singh ◽  
Kaushlendra Dubey ◽  
Rajiv K. Srivastava ◽  
Supreet Singh Bahga
Keyword(s):  
Flow Rate ◽  
Flow Behavior ◽  
Polymer Concentration ◽  
Viscoelastic Behavior ◽  
Scaling Behavior ◽  
Jet Stability ◽  
Polymeric Solutions ◽  
Newtonian Liquids ◽  
The Stability ◽  
Viscoelastic Liquids

Abstract An electrohydrodynamic (EHD) jet forms when a leaky-dielectric liquid issuing out of a needle is accelerated and stretched by electrostatic forces. Stability and scaling behavior of the EHD jet of polymeric solutions depend on electrostatics, fluid mechanics and rheology of the liquid. While EHD jetting of Newtonian liquids have been described in the literature, the effect of non-Newtonian rheology on EHD jetting is still not well-understood. Therefore, we present a detailed experimental investigation of the stability and scaling behavior of EHD jets of polymeric solutions that exhibit non-Newtonian flow behavior. The stability of cone-jet was analyzed by varying flow rate, electric field and polymer concentration. Experiments were performed for polymeric solutions of polycaprolactone (PCL) dissolved in acetic acid. Our experiments show that non-Newtonian viscoelastic behavior can significantly alter the stability characteristics of the EHD jet. We have found that increase of elasticity of polymeric solutions results in enhanced jet stability. Finally, we present the dependence of experimentally measured diameter dj of the EHD jet on the flow rate Q. Experimentally measured diameter of the EHD jet scales as dj ∼ Q0.65 for both Newtonian and non-Newtonian viscoelastic liquids, which can be attributed to dominant inertia forces in our experiment.

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