Article
Chemistry, Multidisciplinary
Evgenii S. S. Baranovskii
Summary: In this paper, new exact solutions for the unidirectional non-isothermal flow of a second grade fluid in a plane channel with impermeable solid walls are obtained, considering the fluid energy dissipation in the heat transfer equation. Time-independent flow driven by pressure gradient is assumed. Various boundary conditions, including no-slip conditions, threshold slip conditions, and mixed boundary conditions, are considered. The dependence of solutions on the boundary conditions is discussed, and explicit relationships for the model parameters to guarantee slip or no-slip regime on the boundaries are established.
Article
Acoustics
Anna Katsiavria, Demetrios T. Papageorgiou
Summary: This article considers the stability of immiscible two-fluid Couette flows with slip present at the liquid-liquid interface. A nonlinear asymptotic theory is developed for a flow geometry in which a thin layer slips over a thick fluid layer. A nonlocal, nonlinear evolution equation is derived, valid at finite Reynolds numbers, slip lengths, viscosity and density ratios. The linear spectrum is calculated and it is shown that slip introduces dispersion, reducing instability or enhancing stability in geometries containing a thin layer.
Article
Engineering, Multidisciplinary
R. Chabiniok, J. Hron, A. Jarolimova, J. Malek, K. R. Rajagopal, K. Rajagopal, H. Svihlova, K. Tuma
Summary: This study aims to understand the flow characteristics of three-dimensional incompressible Navier-Stokes fluid in tubes with a sinusoidal extension. The research is significant for its implications on blood flow through the aortic root, and reveals variations in flow attributes under different slip conditions.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2022)
Article
Thermodynamics
Kai-Xin Hu, Yan Huang, Xin-Yuan Zhang, Sheng Wang, Qi-Sheng Chen
Summary: The paper analyzes the flow of nanofluids in a channel with linearly varying wall temperature, applying a non-uniform equilibrium fluid medium model. Results show different distributions and variations in nanoparticle concentration and fluid properties under different cooling or heating conditions.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Mathematics
Yun Wang, Chunjing Xie
Summary: In this paper, the uniqueness and uniform structural stability of Poiseuille flows in an infinitely long pipe with Navier boundary conditions are established for steady axisymmetric solutions of Navier-Stokes system. This is crucial for studying the general Leray problem for flows in a general infinitely long nozzle. The key point is the uniform estimate with respect to both the flux of flows and friction coefficient in Navier boundary conditions. The partition of the two-dimensional plane for parameters, friction coefficient, and Fourier variable associated with the axial coordinate plays a key role in achieving these estimates.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2023)
Article
Mathematics, Applied
Yun Wang, Chunjing Xie
Summary: In this paper, the uniqueness and structural stability of Poiseuille flows for axisymmetric solutions of steady Navier-Stokes system with Navier boundary conditions in a periodic pipe are proven. The stability is also shown to be uniform with respect to both the flux and the slip coefficient of Navier boundary conditions. Furthermore, it is demonstrated that the nonzero frequency part of the velocity is bounded by a negative power function of the flux as long as the flux is suitably large. The analysis highlights the importance of uniform linear structural stability and detailed analysis of boundary layers and swirl velocity corresponding to the flux and slip coefficients in different regimes.
MATHEMATICAL MODELS & METHODS IN APPLIED SCIENCES
(2023)
Article
Mechanics
Vignesh Ramakrishnan, Remil Mushthaq, Anubhab Roy, S. Vengadesan
Summary: In this study, the effect of wall slip on the stability of a two-layered plane Poiseuille flow was investigated using mathematical modeling and numerical methods. It was found that wall slip has both stabilizing and destabilizing effects on the flow system.
Article
Mechanics
Sajjad Azimi, Tobias M. Schneider
Summary: The study investigates the impact of symmetry breaking on the three-dimensional plane Couette flow homoclinic snaking, revealing that wall-normal suction can modify the bifurcation structure of solutions. This modification disrupts the connected snakes-and-ladders structure and leads to the creation of previously unknown solution branches.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Multidisciplinary
Xiaoyang Xu, Jie Cheng, Sai Peng, Peng Yu
Summary: In this study, a smoothed particle hydrodynamics (SPH) method is developed to simulate viscoelastic fluid flows governed by the Phan-Thien-Tanner (PTT) constitutive equation. The method is validated by comparing its solutions with those obtained by the finite volume method (FVM). The method is also used to simulate the impact behavior and dynamics of a viscoelastic droplet, and the influences of various parameters are investigated. The results demonstrate the accuracy and capability of the SPH method in describing the rheological properties and surface variation characteristics of viscoelastic fluid flows.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2024)
Article
Mathematics
Kaijian Sha, Yun Wang, Chunjing Xie
Summary: In this paper, the authors prove the uniform nonlinear structural stability of Poiseuille flows with arbitrarily large flux in a two-dimensional periodic strip. They establish the a priori estimate for the corresponding linearized problem by analyzing the associated boundary layers. The well-posedness theory for the Navier-Stokes system is also proved, even when the L2-norm of the external force is large. These results demonstrate the uniqueness of solutions for the steady Navier-Stokes system, even when the flux is large and the flow is not symmetric.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kai Tian, Shujuan An, Guangpu Zhao, Zhaodong Ding
Summary: This study provides analytical and numerical solutions for an electromagnetohydrodynamic flow using a Caputo time-fractional Maxwell model. The influence of the electric double layer at the solid-liquid interface is considered. The results show the presence of resonance behavior in the flow, and compared with the classical Maxwell fluid, the slip velocity and resonance behavior of the fractional Maxwell fluid are suppressed.
Article
Mechanics
H. Rahmani, H. Kumar, J. Greener, S. M. Taghavi
Summary: This study investigates the inertial flows of a yield stress fluid in a channel with a superhydrophobic groovy wall using numerical computations. The superhydrophobic wall is modeled with slip and stick arrays, while the viscoplastic rheology is modeled using the Bingham constitutive model. The study focuses on the effects of flow parameters on various flow variables and addresses the interplay between yield stress fluid rheology, wall superhydrophobicity, and flow inertia.
Article
Polymer Science
Wangqing Wu, Fengnan Duan, Baishun Zhao, Yuanbao Qiang, Mingyong Zhou, Bingyan Jiang
Summary: Wall slip has a direct impact on the molding quality of plastic parts. This study presents an effective modeling method based on united-atom molecular dynamics simulations to investigate the flow behavior of polymer melts in nanochannels. The results show that the united-atom molecular dynamics model outperforms the commonly used FENE model in describing the flow behavior. The slip velocity increases with the driving force and exhibits opposite trends under different orders of magnitude of the wall-fluid interactions.
Article
Mathematics, Applied
Yueqiang Shang, Hongtao Ran
Summary: We propose and investigate a parallel subgrid stabilized algorithm for simulating the incompressible Navier-Stokes equations with nonlinear slip boundary conditions. The algorithm employs finite element discretizations and completely overlapping region division for parallelization, where a elliptic projection operator is utilized to define the stabilization term. It has attractive features of global subproblem solving, easy implementation, advantages inheritance, and optimal convergence rate.
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B
(2023)
Article
Automation & Control Systems
Wulin Fan, Yuli Sun, Qinghuai Su, Jianshe Zhao, Fanxuan Yang
Summary: The study focused on the impact of wall-slip velocity of abrasive medium on the workpiece material removal rate in abrasive flow machining process. The coupling effect of wall shear stress and workpiece surface roughness on wall-slip characteristics was explored. A novel method based on fluid mechanics and AFM experiments was proposed to determine wall-slip velocity, and power-law mathematical models were derived to describe the relationship between wall-slip velocity, wall shear stress, and workpiece surface roughness. The models were validated through verification tests, and the results showed that the proposed method and mathematical models improved the prediction accuracy of MRR in AFM process.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Mathematics, Applied
Kostas D. Housiadas, Georgios C. Georgiou
APPLIED MATHEMATICS AND COMPUTATION
(2018)
Article
Mechanics
Evgenios A. Gryparis, Spyros D. Gkormpatsis, Kostas D. Housiadas, Roger I. Tanner
Article
Mechanics
Kostas D. Housiadas, Antony N. Beris
Article
Physics, Fluids & Plasmas
Kostas D. Housiadas
PHYSICAL REVIEW FLUIDS
(2019)
Article
Engineering, Multidisciplinary
Kostas D. Housiadas
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2020)
Article
Mechanics
Spyros D. Gkormpatsis, Evgenios A. Gryparis, Kostas D. Housiadas, Antony N. Beris
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2020)
Article
Mechanics
Kostas D. Housiadas, Roger Tanner
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2020)
Editorial Material
Mechanics
Kostas D. Housiadas, Georgios C. Georgiou
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2020)
Article
Mechanics
Kostas D. Housiadas, Jeremy P. Binagia, Eric S. G. Shaqfeh
Summary: In this study, we investigated various aspects of the spherical squirmer model in weakly elastic fluids using large-scale numerical simulations and asymptotic methods. Our findings show that the low-Wi region plays a crucial role in enhancing speed and rotation rate in perturbation solutions.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Kostas D. Housiadas
Summary: This study theoretically investigates an active, self-propelled, spherical microbody in a weakly viscoelastic matrix fluid using analytical techniques. Three dimensionless numbers arise from the elastic stress in the governing equations, and the impact of slip parameters on singularity in viscoelastic stress for different constitutive models is discussed. The effect of secondary slip and swirl parameters on swimming velocity enhancement, as well as the variety of swimming behaviors influenced by the secondary slip parameter, are emphasized.
Article
Mechanics
Spyros D. Gkormpatsis, Kostas D. Housiadas, Antony N. Beris
Summary: This study analytically investigates the effect of perfect slip boundary conditions on the steady translation of a spherical particle in a viscoelastic fluid. It is found that under perfect slip conditions, the relative drag force on the sphere increases monotonically with viscoelasticity.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Mechanics
Kostas D. Housiadas, Christos Tsangaris
Summary: Lubrication theory is extended to study the laminar flow of an incompressible and highly viscous simple Newtonian fluid in microfluidic channels and tubes with variable geometry. The analysis includes different shapes for the walls and axisymmetric tubes with variable circular cross section, and derives analytical expressions for the average pressure drop.
Article
Mechanics
Kostas D. Housiadas
Summary: This study investigates the performance of two-point Pade approximants on the truncated series solutions for the shear and elongational viscosities of viscoelastic flows modeled with the Giesekus constitutive equation. Low- and high-order two-point diagonal Pade approximants are constructed and found to predict the right trends over the entire range of Weissenberg number, with the high-order formula being more accurate. The results demonstrate the analytical predictability of viscoelastic phenomena using the proposed two-point Pade non-linear analysis.
Article
Mechanics
Kostas D. Housiadas, Christos Tsangaris
Summary: In this study, the effect of Navier slip in the steady, laminar flow of a highly viscous and incompressible Newtonian fluid in a microfluidic channel with variable geometry is investigated. Analytical expressions in series form for the pressure drop are derived, and it is shown that slip at the walls substantially reduces the required pressure drop and facilitates fluid transport. Additionally, the higher-order terms in the asymptotic solution provide important information for the field variables and major quantities of interest in this type of internal and confined flows.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2023)
Article
Mechanics
Kostas D. Housiadas, Georgios C. Georgiou
Summary: We study the regularized Papanastasiou model in ducts, focusing on symmetric channels and axisymmetric pipes with varying walls. By using the classic lubrication approximation and the Lambert W function, we obtain exact analytical solutions for the isothermal, steady and creeping flow field. These solutions reduce to the analytical solutions for ideal yield-stress Bingham and Newtonian fluids under specific parameter values of the Papanastasiou model. The analytical solutions are then used to calculate the average pressure drop required to maintain constant volumetric flowrate through the duct, with emphasis on the effects of Bingham and regularization numbers, as well as the amplitude of undulation or wall variation.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)