Article
Engineering, Marine
Cuong Mai Bui, Thinh Xuan Ho
Summary: This study numerically investigates the flow characteristics of kaolinite mixed with water passing a cylinder near a moving wall. The results show that the flow regime is influenced by the gap ratio, Reynolds number, and Bingham number. At small gaps, the drag and lift coefficients increase with decreasing gap size.
Article
Mechanics
Wenxi Wang, Roger E. E. Khayat, John. R. R. de Bruyn
Summary: In this study, the theoretical analysis of the impact of a jet on a circular disk and the hydraulic jump of a Herschel-Bulkley viscoplastic fluid were examined. The depth-averaging approach was used for the supercritical region, and the subcritical flow was assumed to be inertialess of the lubrication type. The jump was treated as a shock, considering the balance of mass and momentum in the radial direction, including the effect of surface tension. The results showed that a viscoplastic jet does not experience the discontinuity observed in a Newtonian film, and the jump occurs closer to the impingement zone with increasing yield stress. The viscosity has minimal influence on the jump location and height, except for low yield stress, and only the yielded-layer remains sensitive to the power-law rheology. Additionally, the study found that the jump does not occur if the disk is smaller than a critical size. The results also demonstrate a nearly constant downstream Froude number for viscoplastic fluids, and the findings can be applied to Bingham, power-law, and Newtonian fluids.
Article
Construction & Building Technology
Kousalya Ramachandran, Ponmalar Vijayan
Summary: This study investigates the synergistic impact of a ternary binder composed of beta-hemihydrate, clinkers, and slag. The results show that the incorporation of slag and clinkers significantly improves the rheological performance and compressive strength of the binder, and leads to the formation of various hydration products.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Mechanics
O. M. Lavrenteva, I. Smagin, A. Nir
Summary: The sedimentation process of a deformable compound drop, consisting of a viscoplastic fluid shell and a viscous core, in an unbounded Newtonian medium is simulated using a boundary integral approach. The flow is approximated as quasi-stationary creeping flow, with the non-Newtonian stress treated as a source term. The study focuses on the dynamics of interface deformation and un-yielded zones inside the shell, and computations are performed for compound drops with different shell thickness and physical parameters.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Mechanics
Larisa Muravleva
Summary: This study examines the Poiseuille flow of a Bingham fluid with the yield slip condition at the wall, solving the governing equations with the accelerated augmented Lagrangian method. Numerical simulations are conducted for flow in pipes with various cross sections, revealing complex flow patterns and identifying different flow regimes under the combined effects of viscoplasticity and slip. The evolution of unyielded regions is also studied in depth.
Article
Chemistry, Applied
Ruiqi Li, Pengguang Wang, Aiqin Ma, Hongbin Zhang
Summary: This study investigated the time-dependent rheological characteristics of dysphagia management-oriented model polysaccharide solutions and their relationship with structural changes. The results showed that compared to konjac glucomannan solutions, both xanthan gum and carboxymethylated curdlan solutions exhibited significant thixotropic behavior with different timescale responses and concentration dependence. The observed differences in their hysteresis loop area and shape were attributed to their distinct intermolecular association and networks.
FOOD HYDROCOLLOIDS
(2023)
Article
Thermodynamics
Maksim A. Pakhomov, Uzak K. Zhapbasbayev
Summary: The research developed and simulated a mathematical model of the movement and heat transfer of a turbulent non-isothermal non-Newtonian fluid through a pipe wall with a cold surrounding space. It was found that the fluid properties gradually transformed from Newtonian to a viscoplastic non-Newtonian Bingham-Schwedoff fluid state as heat transferred through the pipe wall, resulting in significant changes in fluid velocity, properties, and turbulent kinetic energy as the fluid moved through the pipe.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Mechanics
Lorenzo Fusi, Benedetta Calusi, Angiolo Farina, Fabio Rosso
Summary: This paper investigates the two-dimensional linear stability of a Papanastasiou fluid flowing down an inclined plane. The study reveals that the stability of the Papanastasiou fluid is dependent on the material parameters, the angle of inclination of the plane, and the prescribed inlet discharge. Additionally, the critical Reynolds number is found to be influenced by the yield stress, indicating the destabilizing effect of the yield stress. The results highlight the significant differences in stability characteristics between the regularized flow and the exact Bingham fluid, even if they appear similar.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Mechanics
Mario F. Letelier, Dennis A. Siginer, Edgardo Gonzalez
Summary: This study investigates the steady flow of the viscoplastic Bingham and Herschel-Bulkley (H-B) fluids in tubes of non-circular cross-section. The solution methodology allows the mapping of the flow field for high Bingham numbers in straight tubes with non-circular axially-symmetric but otherwise arbitrary cross-sectional contours. The effects of shear rate dependent viscosity on the formation of plug and stagnation zones are examined.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Mohammad Saeid Aghighi, Christel Metivier, Sajad Fakhri
Summary: The study aims to investigate whether slip affects the Rayleigh-Benard convection of viscoplastic fluids in cavities and under what conditions. The findings reveal that wall slip determines two essential yield stresses and that the possibility of slipping on the wall increases the buoyancy force, facilitating the onset of Rayleigh-Benard convection. This research contributes to a new understanding of the behavior of viscoplastic fluids resulting from slipping.
MULTIDISCIPLINE MODELING IN MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Physical
N'dri Arthur Konan, Eilis Rosenbaum, Mehrdad Massoudi
Summary: This study numerically examines the dynamics of air bubbles in a column of cement slurry. The results show that the mean diameter and rise velocity of the bubbles decrease with the gas flow rate. The rising of the bubbles is controlled by breakup events and relatively weak path instabilities, independent of the gas flow rate. Additionally, the yielded region is larger for the Herschel-Bulkley model compared to the Bingham fluid model by approximately 10%.
Article
Mechanics
G. C. Georgiou, R. R. Huilgol
Summary: The Cheeger constant is the minimum ratio of the perimeter to the area of a given domain. It is related to the reciprocal of this ratio, M, and the minimum pressure gradient, G, for sustaining a steady flow. This study also describes different methods for determining the Cheeger constant for various geometric shapes.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Construction & Building Technology
Jacek Golaszewski, Grzegorz Cygan, Michal Drewniok, Aleksandra Kostrzanowska-Siedlarz
Summary: The study aimed to determine the relationship between rheological parameters of model mortars and self-compacting concrete (SCC), focusing on static yield stress and thixotropy coefficient. It was found that static yield stress is influenced by water/cement ratio, type of HRWR, and cement type, while thixotropy coefficient primarily depends on water/cement ratio. The significance of thixotropic effect on shear strength diminishes over time.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Lex Reiter, Timothy Wangler, Nicolas Roussel, Robert J. Flatt
Summary: This paper investigates the specific yield stress evolution in digital fabrication processes with concrete and proposes a method using displacement controlled continuous slow penetration tests to achieve this goal. The study provides a model understanding and specific suggestions for measurement. The results show that the force recorded in the penetration tests scales linearly with independent measurements of yield stress, and a model adapted from soil-mechanical stability predicts the relationship between penetration force and yield stress. The findings have significant implications for structural build-up in digital fabrication.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Mechanics
N. J. Balmforth, R. Craster, D. R. Hewitt
Summary: This paper discusses a collection of important papers on non-Newtonian fluid mechanics published in the decade following World War II, with an emphasis on Oldroyd's work on viscoplastic fluids. It also covers subsequent developments stemming from Oldroyd's advances and presents new results guided by his work.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2021)
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.
