Article
Physics, Fluids & Plasmas
Nayeon Park, Jaewook Nam
Summary: This paper presents an in-depth analysis of pulsatile shear-thinning flows in two-dimensional channels by introducing the non-Newtonian Womersley number. It is found that the shape of the master curve is determined by the shear thinning degree, and the competition between viscous and pulsatile time scales can be appropriately described by this number.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Mechanics
P. Poungthong, C. Kolitawong, A. J. Giacomin
Summary: This paper analyzes the flow of liquid during the calendering process and provides analytical solutions and methods for calculating flow rate.
Article
Polymer Science
Vania Pais, Pedro Silva, Joao Bessa, Hernani Dias, Maria Helena Duarte, Fernando Cunha, Raul Fangueiro
Summary: Low-velocity impact can cause serious damage, and the development of barriers that can absorb impact energy and protect the other side is the ideal solution. Auxetic materials and shear thickening fluids are two technologies with high energy absorption capabilities. By combining auxetic knits and shear thickening fluids, high performance in energy absorption can be achieved.
Article
Mathematics, Applied
Milan Pokorny, Maja Szlenk
Summary: We investigate the existence of weak solutions for a system of partial differential equations that models the behavior of a compressible non-Newtonian fluid at low Reynolds numbers. Despite the lack of L∞ estimate on the velocity divergence, we are able to construct these weak solutions. By combining the regularity theory for singular operators with a logarithmic integral inequality for BMO functions, we adapt the method from Feireisl et al. (2015) to accommodate more relaxed conditions on the velocity.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Chemistry, Analytical
Jiaxuan Zheng, Jialu Wang, Yongjun Jian
Summary: In this article, the performance of electro-osmotic thrusters filled with non-Newtonian power-law fluids in a microchannel was theoretically investigated. Results show that the performance curves depend strongly on the flow behavior index and the electrokinetic width. It is found that non-Newtonian pseudoplastic fluids are the most suitable propellant solvents in micro electro-osmotic thrusters.
Article
Materials Science, Multidisciplinary
Alessio Pricci, Marco D. de Tullio, Gianluca Percoco
Summary: This paper formulates mathematical models to describe the fluid flow of non-Newtonian fluids inside ducts with convergent and cylindrical sections. The models are validated through comparisons with computational fluid dynamics solutions and show potential in predicting important quantities for processes like 3D printing.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Multidisciplinary
Zhibin Sun, Baojun Shen, Yu He, Jiecai Long, Xiaobin Zhan, Yujin Li, Xiwen Li
Summary: This study evaluates the relationship between extrusion velocity, fluid viscosity, and extrusion pressure during extrusion of highly viscous fluids using a validated CFD model. The results show that the evolution of extrusion pressure can be divided into two stages and an increase in extrusion velocity and fluid viscosity leads to a linear increase in pressure.
KOREAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Engineering, Petroleum
Yanan Ding, Daoyong Yang, Hai Huang, Haiwen Wang
Summary: A novel numerical scheme based on the Eulerian-Lagrangian method has been developed to simulate proppant transport and placement behavior considering non-Newtonian fracturing fluids. The study identified the factors dominating proppant transport and placement, such as the concentration of proppants, the nature of the fluid, and the density and size of proppants.
Article
Mechanics
Xu Yang, Shaowei Wang, Moli Zhao, Yue Xiao
Summary: This study examines the unsteady oscillatory electroosmotic flow of Maxwell fluid in a microchannel with an isosceles right triangular cross section, using a numerical method due to the difficulty of theoretical solution. The numerical solutions illustrate the impact of certain dimensionless variables on velocity profiles.
Article
Engineering, Mechanical
Antonio Zippo, Giovanni Iarriccio, Luca Bergamini, Elena Colombini, Paolo Veronesi, Francesco Pellicano
Summary: This paper presents the results of an extensive experimental campaign on the dynamic interactions between an elastic structure and a non-Newtonian fluid. The system dynamics has been analyzed in the presence of different fluid levels and high energy tests have been performed. The onset of complex dynamics has been detected using Fourier spectra and bifurcation diagrams.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Mathematics
Bilal Al Taki
Summary: The purpose of this paper is to study the well-posedness of a class of non-Newtonian fluid dynamics equations. These equations have a non-linear constitutive relation that connects the stress state with the rate of deformation. We prove the local-in-time existence and uniqueness of strong solutions for two important models: the Power Law model and the Bingham model. The result for the Power Law model holds in a periodic domain, while the result for the Bingham model is limited to one-dimensional case due to its discontinuous constitutive relation caused by phase transitions during flow changes.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2023)
Article
Mechanics
Elif Kayaalp Ata, Ilyas Kandemir
Summary: The steady, laminar, incompressible, axisymmetric stenotic blood flow is investigated using a non-polynomial solution assumption. The wall geometry of the stenosis is modeled as a fixed cosine curve, and the blood rheology is modeled as a generalized power-law fluid. The variations of the coefficients for the velocity profiles are calculated analytically, and the obtained results are validated against Newtonian cases and previous literature. The study concludes that the separation and reattachment points and the existence of the separation-reattachment region are directly related to one of the coefficients in the non-polynomial solution assumption. The Reynolds number to power-law exponent ratio is significant in characterizing the flow streamlines, and a simplified formula for Reynolds number is introduced for blood-like power-law fluids.
ARCHIVE OF APPLIED MECHANICS
(2022)
Article
Mechanics
Wenjun Yuan, Mengqi Zhang, Boo Cheong Khoo, Nhan Phan-Thien
Summary: Our direct numerical simulations revealed that a stable chain can be formed for rising bubbles in viscoelastic liquid, but multiple small bubbles in a vertical file may become unstable as the bubble group ascends due to the distinct oscillation of the uppermost bubble. The accumulation of viscoelastic normal stresses promotes the aggregation of rising bubbles, while the non-monotonic polymer stretching induces near-field repulsion, stabilizing the successive chain of bubbles. Additionally, large bubble deformation enhances the accumulative polymeric normal stress effect, allowing for the formation of more stable vertical chains with increasing initial spacing.
Article
Mechanics
Facundo Cabrera-Booman, Nicolas Plihon, Mickael Bourgoin
Summary: The settling behavior of individual spheres in a quiescent fluid was experimentally studied. The mean trajectory angle with the vertical showed complex behavior as the parameters Gamma and Ga varied. The transition from planar to non-planar trajectories and the emergence of semi-helical trajectories were observed, especially for denser spheres.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Engineering, Chemical
Tomas Jirout, Dita Jiroutova
Summary: The current literature mainly focuses on the settling behavior of isometric particles in Newtonian and non-Newtonian fluids. However, this cannot be applied to the sedimentation of non-isometric particles in non-Newtonian fluids. To address this, the authors conducted systematic experiments to study the hindered settling velocity of a cloud of non-isometric particles in high-viscosity and pseudoplastic liquid. The results showed that the settling velocity of fiber particles is proportional to the porosity on exponent 22.1, which is significantly larger compared to the exponent for spherical particles.
