Article
Chemistry, Physical
Manish Kumar, Derek M. Walkama, Arezoo M. Ardekani, Jeffrey S. Guasto
Summary: This study investigates the role of viscoelastic instability in fluid flow through porous media at high Peclet numbers. The results show that viscoelastic instability enhances transverse dispersion in ordered media, while preferential flow paths enhance longitudinal dispersion.
Article
Multidisciplinary Sciences
M. R. Rezaie, M. Norouzi, M. H. Kayhani, S. M. Taghavi, Mirae Kim, Kyung Chun Kim
Summary: This study investigates the effect of fluid elasticity on axisymmetric droplets colliding with pre-existing liquid films, using both numerical and experimental approaches. The results indicate that the fluid's elasticity can enlarge the crown dimension at different thicknesses of the fluid film. Additionally, the extensional force in the crown wall can control the crown propagation at intermediate values of the Weissenberg number. Furthermore, the effects of the Weber number and the viscosity ratio on this problem are more significant at higher values of the Weissenberg number.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
Manish Kumar, Derek M. Walkama, Arezoo M. Ardekani, Jeffrey S. Guasto
Summary: In this study, we investigated the mechanical dispersion of viscoelastic fluid flow through porous media. Our findings from microfluidic experiments and numerical simulations demonstrate that viscoelastic instability enhances dispersion transverse to the mean flow direction. Additionally, we observed that preferential flow paths can affect the instability and transport processes.
Article
Physics, Fluids & Plasmas
Gunnar G. Peng, Callum Cuttle, Christopher W. Macminn, Draga Pihler-Puzovic
Summary: The article introduces a circular Hele-Shaw cell bounded by a volumetrically confined elastic solid, which can act as a fluidic fuse. When the flow rate exceeds a critical value, the device can interrupt the flow. It is found that the injection of gas increases the critical flow rate of choking via two mechanisms. Moreover, for large injection rates, the outlet flow rate becomes independent of the injection rate and depends only on the instantaneous position of the interface.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
M. Norouzi, M. K. Sheykhian, M. M. Shahmardan, A. Shahbani-Zahiri
Summary: Through experiments, the study investigated the impact behaviors of different fluid droplets on solid surfaces, showing significant influences of impact velocity, angle, surface wettability, and fluid properties on the dynamic behaviors of droplets in spreading and receding stages. The spreading and receding velocities and lengths of droplets can vary under different conditions.
Article
Biochemical Research Methods
Nan Xiang, Silin Wang, Zhonghua Ni
Summary: The device successfully addresses the competition between inertia effect and viscoelasticity effect by utilizing secondary flow to convert multi-train focusing into single-train focusing in low elasticity viscoelastic fluids. The effects of particle diameter, operational flow rate, polymer concentration, and channel dimension on particle focusing performances were systematically explored and discussed. The device enables single-train focusing of particles in viscoelastic fluids with low elasticity, offering advantages of planar single-layer structure, and sheathless, external-field free operation.
Article
Mechanics
Evgeniy Boyko, Ivan C. Christov
Summary: We analyze the fluid-structure interaction between the flow of an Oldroyd-B fluid and a deformable channel. We provide a theoretical framework for calculating the effect of the fluid's viscoelasticity on the flow rate-pressure drop relation and channel deformation. By identifying characteristic scales and dimensionless parameters, and using the lubrication approximation and perturbation expansion, we derive an expression for the pressure as a function of the channel's non-uniform shape in the weakly viscoelastic limit. We show the leading-order effect of the interplay between the viscoelasticity of the fluid and the compliance of the channel on the pressure, deformation, and flow rate-pressure drop relation.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Engineering, Chemical
Huan-Chang Tseng
Summary: In capillary rheometry of a polymer melt, the total pressure drop is composed of shear viscosity, extensional viscosity, and normal stress differences. Viscoelastic constitutive equations have been traditionally used for accurate predictions, however, investigation of the primary components has been difficult in past experiments and computations. The improved White-Metzner viscoelastic constitutive equation coupled with weighted shear/extension viscosity is significant for the analysis of extension-induced and shear-induced pressure drops, along with a small contribution from normal stress differences.
INTERNATIONAL POLYMER PROCESSING
(2023)
Article
Mechanics
David F. James, Caitlin A. M. Roos
Summary: Experimental measurements using four different Boger fluids in long converging channels showed that only one produced reliable pressure-drop data, matching that of an equivalent Newtonian fluid. While elasticity had no apparent effect, significant die swell was observed at the channel exit.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2021)
Article
Engineering, Chemical
Fouad Azizi, Walid Abou-Hweij, Noureddine Lebaz, Nida Sheibat-Othman
Summary: This study numerically investigated the flow through an SMX+ mixer. The results showed a three-dimensional velocity field dominating the flow within the mixer, with significant fluctuations in the distribution of strain rate and vorticity magnitudes. The extensional efficiency increased substantially in the first part of each mixer, indicating good dispersion behavior, but decreased downstream of the last element. This was attributed to the presence of a rotational core in the flow, spiraling on its axis as it moved downstream.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Polymer Science
Geunyeop Park, Jangho Yun, Changhoon Lee, Hyun Wook Jung
Summary: The draw resonance instability of viscoelastic Giesekus fluids depends on the Deborah number and a single material parameter alpha G. In the intermediate range of alpha G, the stability status changes distinctively with increasing De. The changes in transit times of kinematic waves for varying De reflect the effect of alpha G on the stability.
Article
Mechanics
H. Asadi, M. Pourjafar-Chelikdani, S. M. Taghavi, K. Sadeghy
Summary: A new generalized Richards equation is developed for highly shear-thinning liquids using the concept of effective viscosity. The model is validated against experimental data on spontaneous imbibition of two pusher liquids by a tight sandstone. The study shows that shear-thinning can greatly reduce the time required for gas recovery in a homogeneous tight sandstone. However, prolonged use of shear-thinning liquids may lead to a slight decrease in gas recovery compared to Newtonian fluids. In a two-layer non-homogeneous system, the uptake of liquid mass can be smaller depending on the microstructure of the layers. It is predicted that sufficiently shear-thinning liquids can significantly enhance gas recovery.
Article
Mechanics
A. A. Avramenko, I. Shevchuk, A. Tyrinov, M. M. Kovetskaya, N. P. Dmitrenko
Summary: This article presents the results of studying the flow of a Newtonian fluid in a narrow wedge-shaped slot with a moving wall and obtaining a solution for slip boundary conditions. The study shows the influence of slip conditions on flow parameters and identifies different types of flow in the diverging and converging sections of the channel.
Article
Engineering, Mechanical
Mohammad Mahdi Badami, Alireza Riasi, Kayvan Sadeghy
Summary: This study investigates the laminar fluid hammer phenomenon in viscoelastic fluids through a straight pipe using the finite-volume method. The results show that viscosity ratio and Deborah number have significant effects on the impact, while the extensibility parameter has virtually no impact.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2021)
Article
Thermodynamics
S. Saha, P. Biswas, A. N. Das, A. Kumar, M. Kumar Singh
Summary: Using the FVM numerical method, we examined the rheological behavior of blood flow bifurcation at different Reynolds numbers and contraction ratios. The study focused on a planar contraction-expansion channel, which can be compared to regurgitation in the mitral valve. The characteristics of blood flow bifurcation, such as velocity profile, pressure drop, and recirculation length, were analyzed for different conditions. Correlation analyses were conducted to understand the relationship between Reynolds number, contraction ratio, and vortex length.
JOURNAL OF APPLIED FLUID MECHANICS
(2023)
Article
Mechanics
Chen Liu, Jianzhong Lin, Zhenyu Ouyang
Summary: This study simulated the locomotion state and motion type of elliptical squirmers in a channel flow of power-law fluids. The influence of different parameters on the squirmers was explored, and it was found that coupled structures are prone to break and viscosity significantly affects the flow velocity and motion type of squirmers.
Article
Mechanics
E. E. Herrera-Valencia, M. L. Sanchez-Villavicencio, C. Soriano-Correa, O. Bautista, L. A. Ramirez-Torres, V. J. Hernandez-Abad, F. Calderas
Summary: This study investigated the electroosmotic flow of a viscoelastic fluid in a capillary system. The rheology of the fluid was characterized by a novel generalized exponential model equation, and the effect of charge density on the double-layer field and electrical forces was analyzed. Mathematical models were used to describe the rheological properties and flow performance of the fluid, and experimental data were used to make predictions. The study also examined the influence of applied forces on the structure of the fluid.
Article
Mechanics
Stefano Amadori, Giuseppe Catania
Summary: This article presents a multi-step, iterative technique for locally non-parametric identification of the standard linear solid (SLS) material model using fractional order time differential operators. Test input data consists of a set of identified material complex modulus values estimated at different frequency values obtained from input-output experimental measurements and quasi-static relaxation measurements on the same specimen. The proposed technique is based on an algebraic procedure to solve an overdetermined system of linear equations in order to obtain optimal values for the unknown parameters of the model. The procedure is non-parametric, as the order of the SLS model is initially unknown.
