Article
Mechanics
Jesse J. Taylor-West, Andrew J. Hogg
Summary: In this study, the flow of non-Newtonian fluids in corners is investigated using both numerical and analytical methods. The results show that, under certain conditions, viscoplastic materials can exhibit eddies similar to those found in Newtonian fluids.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Jesse J. J. Taylor-West, Andrew J. J. Hogg
Summary: The motion of viscoplastic fluid between two rigid plates generates self-similar flow fields due to the absence of inertia. The strain rate is proportional to the angular velocity of the plates and the deviatoric stresses are only dependent on the polar angle and a dimensionless measure of the yield stress. There are unyielded regions adjacent to the boundaries for large angles between the plates, and viscoplastic boundary layers can form when the yield stress is large.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Thomasina V. V. Ball, Neil J. J. Balmforth
Summary: This paper investigates the dynamics of peeling of a viscous fluid spreading underneath a deformable surface skin or crust. The rate of advance is controlled by the peeling dynamics at the fluid front rather than bulk self-similar flow. The study focuses on a skin that deforms either viscously or plastically, where the thin plate of material is governed by the Herschel-Bulkley constitutive law. The research examines how such a skin controls viscous flow underneath, considering constant flux and different types of spreading currents.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mathematics, Applied
Sun-Chul Kim, Hisashi Okamoto
Summary: Here, we provide numerical evidence that suggests the existence of stationary solutions with highly localized vorticity in the two-dimensional Navier-Stokes equations. These solutions appear in Kolmogorov flows with small aspect ratios and high Reynolds numbers. Additionally, in most of the region where vorticity is negligible, the streamlines are nearly straight lines.
APPLIED MATHEMATICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Jinsong Zhang, Shuai Zhang, Jianhua Zhang, Zhiliang Wang
Summary: This study successfully utilized machine learning algorithms to automatically identify, judge, and predict flow patterns and droplet characteristics in digital microfluidic experiments, providing a new approach for intelligent processing of experimental results. By introducing a dimensionless numbers system, the predictive capability of the algorithms was improved, highlighting the importance of selecting traditional dimensionless numbers with physical meanings for successful application of machine learning algorithms.
APPLIED SCIENCES-BASEL
(2021)
Article
Physics, Fluids & Plasmas
C. Jacques, B. Di Pierro, F. Alizard, M. Buffat, A. Cadiou, L. Le Penven
Summary: This paper addresses the linear stability problem of solid body rotating flows with axisymmetric density variations. Considering inviscid disturbances, a nontrivial dispersion relation is obtained, indicating that the instability is of Rayleigh-Taylor type in the cylindrical frame. The viscous correction is derived in the limit of large Reynolds numbers and large azimuthal wave numbers, enabling the determination of the most unstable mode. Theoretical predictions are verified by comparing them to computed eigenvalues and direct numerical simulations.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Torstein Saeter, Olivier Galland, Blandine Feneuil, Havard J. Haugen, Andreas Carlson
Summary: Inspired by geological structures, we investigate the elastohydrodynamic growth of a viscoplastic blister under an elastic sheet resting on a prewetted substrate. The blister growth dynamics follow different regimes depending on how the fluid pressure is set. A plug-like flow inside the blister dictates its dynamics, while the blister's shape is determined by a balance between the fluid's yield stress and the pressure gradient induced by the sheet's deformation.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Emad Chaparian, Ian A. Frigaard
Summary: Viscoplastic fluids can trap bubbles/particles by balancing buoyancy stress with yield stress, depending on the yield number Y. This study investigates the behavior of a bubble suspension in a yield-stress fluid, determining the gas fraction phi that can be held without motion. Short-range interactions increase the critical yield number for bubble clouds, with the critical yield number showing a linear relationship with volume fraction in dilute conditions.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Jianting Zhu
Summary: A new mathematical model is developed to investigate the effects of fractal fractures on the flow of Herschel-Bulkley fluid, finding that factors such as fractal dimension, trace length ratio, and scaling exponent have significant effects on the flowrate ratio.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2022)
Article
Thermodynamics
Mohammad Azad, Dominic Groulx, Adam Donaldson
Summary: This study investigates the effects of geometry, Stefan number, Grashof number, and Rayleigh number on the onset of natural convection in phase change materials. Correlations were developed to estimate the elapsed time or melt volume at the onset of natural convection for given geometry and operating temperature.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Mathematics, Applied
E. D. Fernandez-Nieto, J. Garres-Diaz, P. Vigneaux
Summary: Starting from the Navier-Stokes equation, we derive two shallow water multilayer models for yield stress fluids, taking into account normal stress contributions. A specific numerical scheme is designed to accurately solve the transitions between yielded and unyielded (or pseudoplug) zones. Numerical simulations agree well with physical experiments, allowing for a comparative study with other shallow water and lubrication models.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Mechanics
Minyoung Kim, Eungjun Lee, Do Hyun Kim, Rhokyun Kwak
Summary: This study reveals the unique behaviors of viscoplastic drops on an inclined superhydrophobic surface, including decoupled rolling, sliding, and sticking motions, as well as two distinct rolling modes: viscous rolling and rigid-body rolling. The research indicates that viscoplastic drops exhibit different rolling behaviors based on factors like gravitational, yield, and adhesive stresses. Furthermore, the study categorizes rolling into liquid-like viscous rolling and solid-like rigid-body rolling modes, showing that viscoplastic drops deform and tumble differently on inclined surfaces depending on their Deborah number.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Mechanical
Dasol Jeong, Seibum B. Choi, Jonghyup Lee, Mintae Kim, Hojong Lee
Summary: Tires are crucial elements in a vehicle as they are responsible for the vehicle's performance and control. Intelligent tires with sensors can assist in analyzing and measuring tire characteristics.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Mechanics
S. Akbari, S. M. Taghavi
Summary: We investigated the injection flow of a heavy viscoplastic fluid into a light Newtonian fluid through modeling and experiments. Three distinct flow regimes were observed as the injection rate increased, namely the breakup, coiling, and buckling regimes. A lubrication approximation model was developed to classify the flow regimes based on dimensionless flow parameters.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Stephen J. Walters, Ross J. Turner, Lawrence K. Forbes
Summary: A novel technique is presented for solving flow problems of viscous multi-fluid systems with interfaces, utilizing exact Navier-Stokes equations and a Boussinesq-type approach. The technique is illustrated through a case study of classical Rayleigh-Taylor flow and compared with other models, showing strong support for its effectiveness.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Engineering, Chemical
Paulo Roberto C. Mendes Junior, Ivan R. Siqueira, Roney L. Thompson, Marcio S. Carvalho
Summary: This study investigates planar extrudate swell flows of Newtonian liquids with a viscous liquid-gas interface. Results demonstrate that the extrudate swells dramatically as the interfacial viscosity grows, indicating a clear relationship between parameters.
Article
Energy & Fuels
Rafael de Paula Cosmo, Fabio de Assis Ressel Pereira, Edson Jose Soares, Andre Leibsohn Martins
Summary: This study examines the challenge of calcium carbonate scaling for Brazilian Pre-Salt oil production, analyzing the chemical balance between CO2 and CaCO3. The research found that the role of CO2 in precipitation differs among aqueous, oily, and gaseous phases, with CO2 partitioning between the three phases critically governing the precipitation process. Simulation results confirmed previous findings, but indicated a distinct behavior of CO2 influence with changes in BSW in real-field runs.
Article
Energy & Fuels
Rafael de Paula Cosmo, Fabio de Assis Ressel Pereira, Edson Jose Soares, Emmanoel Guasti Ferreira
Summary: Geothermal sources are crucial energy resources in many cities worldwide, providing electricity and heat. However, operational issues like calcium carbonate precipitation and CO2 degassing can affect the efficiency of geothermal wells, requiring engineers to address these problems for optimal system design and operation.
Article
Mechanics
Vitor Figueiroa Ventura, Joao Felipe Mitre, Roney Leon Thompson
Summary: Waxy crude oils can turn into a gel at low temperatures, causing flow assurance issues during restart due to the higher pressure drop required. This study investigates the impact of cooling process after shutdown on the problem. The results show that the plastic number and the duration of cooling after shutdown play a role in the restart conditions, with higher plastic numbers and longer cooling times leading to more difficult restarts.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Mechanics
Ivanor Martins, Edson J. Soares, Renato N. Siqueira
Summary: In this study, we analyze the polymer scission of a flexible polymer in a turbulent flow in pipelines, particularly focusing on the effect of abrupt contractions. We find that the final value of the drag reduction parameter is independent of the initial molecular weight, which is different from flows in straight tubes without local occurrences. We propose a model that relates the drag reduction parameter to concentration, molecular weight, contraction rate, and the number of passes through the system. Additionally, we observe that the decrease in drag reduction is linearly dependent on the decrease in molecular weight.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Mechanics
Hugo L. Franca, Cassio M. Oishi, Roney L. Thompson
Summary: This work presents a numerical study on the collision of viscoelastic drops under surface tension effects. Different constitutive models for non-Newtonian fluids are considered, and the outcomes of bouncing, coalescence, and separation are analyzed. The study also explores the effects of various parameters on the collision outcomes.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Energy & Fuels
Icaro Coelho, Edson J. Soares, Roney L. Thompson, Fabio de Assis Ressel Pereira, Adriana Teixeira, Leandro Saraiva Valim
Summary: The main flow assurance problem in the oil industry is the formation of gas hydrates in high pressure and low temperature conditions. Tetrahydrofuran (THF) is commonly used to mimic gas hydrates. This study investigates the rheological properties and behavior of THF, finding different outcomes for different mass concentrations and differing from previous literature.
Article
Engineering, Mechanical
Roney L. Thompson
Summary: This study examines the relationship between skew-symmetric tensors in Continuum Mechanics, specifically Motions With Constant Stretch History (MWCSH), the Zorawski condition, and Rivlin-Ericksen (R-E) tensors. Theoretical analysis reveals that the rate-of-rotation of R-E tensors in MWCSH is equal to the skew-symmetric tensor governing this type of motion, extending existing analytical results. The study also presents a compact form for the Zorawski condition, enabling theoretical analysis of inherently unsteady motions.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Mechanical
P. R. S. Costa, R. P. Barboza, R. A. C. Dias, J. L. Favero, A. O. M. Samel, M. A. Cruz, L. F. L. R. Silva, R. L. Thompson, M. P. Schwalbert
Summary: In this study, a model is proposed to predict the treatable size zones for acid reservoir stimulation, considering the coupling between well and reservoir using a 3D approach. The robust numerical code implemented using OpenFOAM(R) demonstrated that the 3D method provides qualitative and quantitative results that cannot be predicted by the simplified 2D model.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Chemical
Allan B. G. Motta, Roney L. Thompson, Mateus P. Schwalbert, Luiz F. L. R. Silva, Jovani L. Favero, Rodrigo A. C. Dias, Raphael J. Leitao
Summary: This paper proposes a flow model considering the non-uniform pore distribution in porous media, and through simulation and analysis, it is found that the non-uniform pore size distribution may be an important factor causing discrepancies between the viscosity functions obtained from rheometric devices and the Darcy equation.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Mechanics
Kelvin C. O. Barbosa, Jordan D. Cussuol, Edson J. Soares, Rafhael M. Andrade, Marcia C. Khalil
Summary: In this study, we investigate the drag reduction of polymers in a Taylor-Couette geometry for a range of concentrations below and above the overlap concentration. It is found that increasing concentration accelerates drag reduction for diluted solutions, but the opposite occurs for concentrated solutions. Our data also suggest that using solutions with concentrations above the overlap concentration can lead to surpassing the maximum drag reduction, which can be attributed to polymer aggregation.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Mechanics
F. O. Silva, I. R. Siqueira, M. S. Carvalho, R. L. Thompson
Summary: We conducted a computational study on free surface flows in the film formation region of a slot coater, considering the rheologically complex interfaces. By solving the equations of motion for incompressible Newtonian liquids coupled with the Boussinesq-Scriven constitutive equation for viscous interfaces, we found that interfacial viscosity plays a significant role in the flow dynamics and operating limits of slot coating. The interfacial viscosity affects the stiffness of viscous interfaces, resulting in changes in stress jumps and retarding the film flow.
Article
Physics, Fluids & Plasmas
A. L. Guilherme, I. R. Siqueira, L. H. P. Cunha, R. L. Thompson, T. F. Oliveira
Summary: We study the impact of external magnetic fields on the dynamics of superparamagnetic ferrofluid droplets and the rheology of dilute ferrofluid emulsions in planar extensional flows. By altering the shape and magnetization of the ferrofluid droplets, the intensity and direction of uniform magnetic fields affect the planar extensional rheology of the emulsions. We observe unconventional stress-strain responses and introduce new extensional material functions to explain these rheological signatures.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Joao P. Cunha, Paulo R. de Souza Mendes, Roney L. Thompson, Elias C. Rodrigues, Erick F. Quintella
Summary: This paper examines the mechanical behavior of microelements dispersed in the bulk flow in a four-roll mill and provides a comprehensive analysis of the flow type seen from the perspective of the microelement. The study takes into account material parameters to generalize a kinematic flow-type classification parameter. The numerical simulation using the finite element method shows how the local flow type varies under different flow conditions and analyzes the deformation of microelements positioned at the stagnation point.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Energy & Fuels
Andre S. Guimaraes, Thiago O. Marinho, Priamo A. Melo, Roney L. Thompson, Marcia C. K. de Oliveira, Marcio Nele
Summary: This study presents a novel coupled kinetic and rheological model for paraffinic wax oil gelation. The crystallization kinetics was investigated using differential scanning calorimetry, while the rheological properties were determined through dynamic oscillatory tests. The effect of cooling rate on fractal dimensional analysis was examined for different wax concentrations. The gathered data were successfully reconciled using scaling models, allowing for the discussion of microstructural characteristics. Additionally, simulations of waxy oil gelation during a pipeline shutdown were conducted based on the observed kinetic and rheological behavior.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Mechanics
Mateus C. Guimaraes, Fernando T. Pinho, Carlos B. da Silva
Summary: A new theory is proposed to describe the conformation state of polymer chains in free turbulent shear flows of viscoelastic fluids. The theory shows the existence of minimum and maximum solvent dissipation reduction asymptotes and four different polymer deformation regimes, based on self-similarity arguments and new scaling relations for the turbulent flux of conformation tensor. In addition, analytical solutions for the self-similar transverse profiles of the conformation tensor components are obtained. The theory is validated through excellent agreement with direct numerical simulations employing the FENE-P rheological model.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2024)