Article
Thermodynamics
A. S. Alhamaly, Majid Khan, S. Z. Shuja, B. S. Yilbas, H. Al-Qahtani
Summary: Stagnation point flow on a linearly stretching surface with heat transfer analysis using nanofluid with variable properties results in larger heat transfer rates compared to homogenous property fluid. The presence of a large volume fraction of nanoparticles in the boundary layer significantly enhances the heat transfer. Additionally, the Prandtl number, stretching rate of the surface, and nanoparticles volume fraction have significant influence on the Nusselt number.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Mathematics, Applied
Golam Mortuja Sarkar, Bikash Sahoo
Summary: This paper investigates the steady three-dimensional Hiemenz flow of a viscous incompressible fluid over a stretching/shrinking sheet. Numerical solutions for the shear stress parameters and displacement thicknesses of the sheet are obtained and compared with asymptotic solutions. Dual solutions of the similarity equations are found for both the stretching and shrinking cases, and a stability analysis reveals the physically reliable solution.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Mathematics, Interdisciplinary Applications
Arif Ullah Khan, A. Al-Zubaidi, Shahid Munir, S. Saleem, Faisal Z. Duraihem
Summary: This study investigates the boundary layer flow for Casson fluid generated by a stretching sheet with cross flows, analyzing three different cases of cross flow with streamwise flow and deriving one-parameter solutions based on material parameters. The similarity solution for the model is obtained from the Weidman solution using proper transformations.Velocity profiles and wall shearing parameters for all types of flows are displayed graphically, showing the impact of the Casson fluid material parameter beta on various flow patterns.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Physics, Multidisciplinary
Mirza Naveed Jahangeer Baig, Nadeem Salamat, Faisal Z. Duraihem, Salman Akhtar, Sohail Nadeem, Jehad Alzabut, Salman Saleem
Summary: This study mathematically models the stagnation point flow over a heated stretching cylinder using the phase flow approach. The interaction between impinging stagnation flow and flow due to the stretching surface of the cylinder is thoroughly interpreted. Exact analytical solutions are computed and evaluated graphically. Heat transport analysis and Nusselt number interpretation are incorporated. The results show a dominant impinging stagnation flow for higher oncoming flow pressure and lower stretching velocity of the cylinder.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Dhurgham Allaw, Norfifah Bachok, Norihan Md Arifin, Fadzilah Md Ali
Summary: This study investigates the behavior of carbon nanotubes at unsteady stagnation points, taking into account the slip effects. Through mathematical modeling and numerical simulations, the relationships between practical quantities and key parameters are obtained and physically interpreted. The study finds that there are double solutions for both extending and shrinking cases, and increasing the volume fraction of carbon nanotubes accelerates the separation of fluid. This research has significant implications for various industries, including processing and biomedical.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Mechanics
R. Ayats, F. Marques, A. Meseguer, P. D. Weidman
Summary: The study investigates Navier-Stokes equilibrium solutions of a viscous fluid confined between two infinite parallel plates, revealing the existence of both two-dimensional and three-dimensional solutions, as well as the disappearance, creation, and annihilation of solutions at different stretching or shrinking rates. Additionally, new families of equilibria are observed near cuspidal codimension-2 bifurcation points when both plates are simultaneously stretching or shrinking at higher rates, exhibiting behavior similar to other planar and cylindrical self-similar flows.
Article
Mathematics, Applied
Patrick D. Weidman
Summary: A new family of three-dimensional viscous stagnation-point flows has been discovered by modifying Hiemenz's two-dimensional outer potential stagnation-point flow and adding periodic radial and azimuthal velocities, depending on the shear-to-strain-rate ratio gamma=b/a.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2021)
Article
Mechanics
Jarrett Boyd, Gram Hepner, Maxwell Ujhazy, Shawn Bliss, Melikhan Tanyeri
Summary: Recent advancements in science and engineering have enabled trapping and manipulation of individual particles and macromolecules in water using a flow-based confinement method. This study demonstrates the feasibility of trapping and manipulating two micro/nanoscale particles using coupled planar extensional flows. The results show that precise control of particle confinement and interparticle distance can be achieved by manipulating strain rates and particle positions. The findings contribute to our understanding of feedback-controlled particle manipulation and have potential applications in polymer science and biology.
Article
Multidisciplinary Sciences
Anwar Saeed, Muhammad Bilal, Taza Gul, Poom Kumam, Amir Khan, Muhammad Sohail
Summary: Fractional calculus is used to describe the function where classical calculus fails. The study investigated the fractional behavior of a hybrid nano liquid flow containing TiO2 and Ag nanoparticles on a stretching sheet, finding that the drifting velocity generated by electric field E significantly enhances the velocity and heat transfer rate in blood. The fractional model is seen as more generalized and applicable compared to the classical model.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
B. Wang, R. Ayats, A. Meseguer, F. Marques
Summary: In this paper, the stability and dynamical relevance of different types of flows between orthogonally stretching parallel plates are explored. It is found that the Stokesian flow is stable, while other flow solutions are unstable. When both plates shrink, a Hopf bifurcation occurs leading to stable time-periodic regimes. Additionally, quasiperiodic flows and chaotic dynamics are observed, but chaotic dynamics is rare.
Article
Materials Science, Multidisciplinary
Dezhi Yang, Muhammad Israr Ur Rehman, Aamir Hamid, Saif Ullah
Summary: The study investigated the effect of a non-uniform heat source/sink on the unsteady stagnation point flow of Carreau fluid past a permeable stretching/shrinking sheet, incorporating additional effects of magnetohydrodynamics, joule heating, and viscous dissipation. The nonlinear partial differential equations were transformed into ordinary differential equations and solved using the Runge-Kutta-Fehlberg technique. The results showed how the fluid flow velocity and temperature of Carreau fluid varied with different parameters, and how the local Nusselt number changed with the Eckert number for both upper and lower branches.
Article
Business, Finance
Ansgar Belke, Jens Klose
Summary: This article introduces a new measure to capture safe haven flows for twelve Euro area countries and estimates the impact on the natural rate of interest. The study shows that the natural rate tends to decrease in countries with safe haven inflows and increase in countries with safe haven outflows.
INTERNATIONAL REVIEW OF ECONOMICS & FINANCE
(2021)
Article
Thermodynamics
J. Cui, N. Naheed, U. Farooq, M. Hussain, M. Sheremet
Summary: This study explores the impact of Cu/H2O and Al2O3/H2O nanofluid flow on mixed convection and investigates the convective phenomena on a permeable shrinking/stretching surface subjected to heat source/sink and magnetic field effects. The results show that the increase in nanoparticle volume fraction enhances the thermal profile, while an increase in the magnetic number raises the magnitude of the skin friction coefficient and reduces the Nusselt number.
JOURNAL OF ENGINEERING THERMOPHYSICS
(2022)
Article
Mechanics
M. Rank, A. Voigt
Summary: This study investigates the influence of varying Gaussian curvature on anomalous vortex-network active turbulence on general surfaces using a numerical approach for a covariant generalized Navier-Stokes equation. The simulation results indicate an alignment of vortex chains with minimal curvature lines of the surface and a dependency of this turbulence regime on the sign and gradient of local Gaussian curvature.
Article
Computer Science, Interdisciplinary Applications
Sergio Pirozzoli, Paolo Orlandi
Summary: This paper proposes a new DNS method for wall-bounded flows, using numerical simulations to derive optimal parameters and grid spacing, and providing a specific prescription for the number of grid points and grid clustering needed for accurate results. The conclusions are supported by high Reynolds number DNS, demonstrating the presence of a near logarithmic layer in the mean velocity profile.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Engineering, Multidisciplinary
M. R. Turner, T. J. Bridges, H. Alemi Ardakani
JOURNAL OF ENGINEERING MATHEMATICS
(2017)
Article
Meteorology & Atmospheric Sciences
B. Cheng, M. J. P. Cullen, J. G. Esler, J. Norbury, M. R. Turner, J. Vanneste, J. Cheng
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2017)
Article
Mathematics, Applied
M. R. Turner
QUARTERLY JOURNAL OF MECHANICS AND APPLIED MATHEMATICS
(2018)
Article
Mechanics
M. R. Turner, P. D. Weidman
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2019)
Article
Mechanics
M. R. Turner, T. J. Bridges
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2019)
Article
Engineering, Multidisciplinary
M. R. Turner, J. R. Rowe
JOURNAL OF ENGINEERING MATHEMATICS
(2019)
Article
Physics, Fluids & Plasmas
P. D. Weidman, M. R. Turner
PHYSICAL REVIEW FLUIDS
(2019)
Article
Meteorology & Atmospheric Sciences
M. R. Turner, J. Norbury
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2020)
Article
Mechanics
M. R. Turner
Article
Mechanics
Matthew R. Turner, Patrick Weidman
Summary: This study examines the impingement of axisymmetric Homann stagnation-point flow on a surface undergoing perpendicular, planar, biaxial stretching, revealing four branches of steady solutions and a spiralling behavior in the surface shear stress parameter plane. The analysis also finds only one stable solution for each set of parameters, indicating limited stability of the solutions.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2021)
Article
Mathematics, Applied
Dan J. Hill, David J. B. Lloyd, Matthew R. Turner
Summary: This paper investigates the existence of localised axisymmetric patterns on the surface of a ferrofluid in the presence of a uniform vertical magnetic field. The study formally explores small-amplitude solutions that remain bounded close to the pattern's centre and decay exponentially away from it. The results present different classes of stationary radial solutions and parameter regions in which various localised radial solutions emerge. The approach taken in this paper outlines a route to rigorously establish the existence of axisymmetric localised patterns in the future.
JOURNAL OF NONLINEAR SCIENCE
(2021)
Article
Physics, Fluids & Plasmas
M. R. Turner, Patrick D. Weidman
Summary: This study examines the flow generated by a biorthogonally stretched membrane under a steadily rotating flow at infinity. It shows that the velocity field of the flow is an exact, self-similar solution of the fully three-dimensional Navier-Stokes equations, governed by a set of four ordinary differential equations. Dual solutions exist when the membrane is stretched in both directions or for a range of parameters where it is stretched in one direction and allowed to shrink in the other. The linear stability analysis reveals that only one solution is stable for a given stretching and rotation rate.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Physics, Fluids & Plasmas
Matthew R. Turner, Richard P. Sear
Summary: The Earth's atmosphere contains suspended particles, which may deviate from the air's path and collide with obstacles. Particle inertia, measured by the Stokes number St, drives this deposition, with a critical value Stc. The deposition amount near Stc follows an unusual scaling law of exp[-1/(St - Stc)1/2], controlled by the flow's stagnation point.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Physics, Fluids & Plasmas
Ryan Poole, M. R. Turner
Summary: A spatiotemporal stability analysis is conducted on a flow representing both jets and wakes, subject to confinement by identical compliant walls. The flow's absolute and convective stability properties are determined by tracking the position of pinch points in the complex wave-number plane. The compliant walls modify the existing shear-induced instabilities and introduce new instabilities, which can become dominant and induce absolute instability into the system.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Essam Nabil Ahmed, Alessandro Bottaro
Summary: This study focuses on the fully developed, steady, incompressible, laminar flow in a channel with rough and/or permeable walls. The influence of micro-structured boundary surfaces on the flow behavior is simulated using high-order effective boundary conditions derived from homogenization theory without empirical parameters. A closed-form solution of the Navier-Stokes equations is obtained for the flow in the channel, incorporating slip velocities, shear stress, and streamwise pressure gradient at each virtual boundary. The accuracy and applicability of the model are validated against full feature-resolving simulations for different textures. The Stokes-based model used to identify slip and interface permeability coefficients in the effective boundary conditions is reliable and accurate up to a certain threshold, beyond which advective effects need to be considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Mustafa Turkyilmazoglu, Faisal Z. Duraihem
Summary: Thermally-driven natural convection in a porous layer is explored theoretically in this work based on Darcy's law. The study focuses on the non-circulating basic cellular flow between two infinitely long horizontal plates and its instability onset. The results show that a circulatory flow and temperature variation along the horizontal axis govern the motion, and the instability can be determined through linear stability analysis and numerical calculations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
P. Roca Ramis de Ayreflor, A. Viudez
Summary: In this study, the inelastic interactions between a small, intense dipole and a weak, neutral monopole in two-dimensional flows are examined. It is found that dipoles with small size but large amplitude can cross and scatter off the neutral vortex, while leaving the vortex stable.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Nilanjan Mondal, Chirodeep Bakli
Summary: This study presents a micro-nanochannel junction with directional flow achieved by a combination of junction geometry and wall functionalization. The system acts as a fluid diode with asymmetric pressure drop and flow rate in the nanochannel. The directional junction transport can be tuned with slip length, providing a key parameter for engineering various applications. The findings contribute to the understanding of flow rectification systems in nanochannels and have implications for capillary blood flow, desalination systems, and energy storage devices.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Ussama Ali, Anas Ghannam, Md Islam, Isam Janajreh
Summary: This study utilizes a passive flow control technique involving a slit through a circular structure to dampen flow-induced vibration. The results demonstrate that the presence of a slit can decrease lift and drag coefficients and suppress flow-induced vibration.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sebastian A. Altmeyer
Summary: This article investigates how an alternating magnetic field can restrict and suppress the generation of vortices in ferrofluidic Couette flow. It finds that when the initially rotating outer cylinder is suddenly stopped, more complex vortex dynamics are generated in the system, and the presence of an alternating magnetic field can modify these dynamics, mainly depending on the modulation amplitude of the field.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Pradeep, L. P. Singh
Summary: This study focuses on the analytical solution to the Riemann problem for a 1-D non-ideal flow of dusty gas with external force. The elementary wave curves, including rarefaction wave, shock wave, and contact discontinuity, were obtained and their implications on density, velocity of flow, and shock speed were examined. The addition of external force results in non-self-similar solutions.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Meng Fan, Antoine Dazin, Gerard Bois, Francesco Romano
Summary: This study investigates the prominent features of the primary instabilities of a turbulent source flow between finite-span parallel rings with spatially modulated inflow conditions rotating at angular rate n. Two different two-dimensional instabilities that occur at large and low flow rates have been traced back to two different physical mechanisms related to jet-wake and mean-core flow, respectively. The effect of the radial aspect ratios on the instability characteristics of the flow between parallel rings is also considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Yasmin Hengster, Martin Lellep, Julian Weigel, Matthew Bross, Johannes Bosbach, Daniel Schanz, Andreas Schroder, Florian Huhn, Matteo Novara, Daniel Garaboa Paz, Christian J. Kahler, Moritz Linkmann
Summary: Using curvature and torsion to describe Lagrangian trajectories provides insights into small and large time scales. Probability density functions (PDFs) of curvature and torsion were calculated for experimental Lagrangian trajectories in different flows, and were compared with experimental and numerical simulation results. The effect of anisotropy on geometry or tracer particle trajectories was quantified using the curvature vector, which was found to be related to velocity fluctuations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Nang X. Ho, Truong V. Vu
Summary: The present paper reports numerical results on the solidification process of a hollow drop on an inclined surface. The drop undergoes deformation and forms an asymmetric tip as the surface angle increases. The solidification time, however, is not affected by the surface angle. The fluid accumulates at the bottom of the drop and the bubble moves upwards before being trapped by solidification. A larger bubble reduces the tip shift. The effect of Bond number and Stefan number on solidification is also considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Idalia Jagodzinska, Bartosz Olszanski, Konrad Gumowski, Slawomir Kubacki
Summary: This study investigates the characteristics of high subsonic and transonic flows through a linear cascade using experimental investigations and numerical simulations. The experiments measured static pressure, flow field, and turbulent intensity, and provided inlet conditions for the numerical simulations. The simulations validated the experimental data and tested the applicability of the turbulence models.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Kun Sung Park, Ali Zamiri, Minsuk Choi, Byung Ju Lee, Jin Taek Chung
Summary: In this study, the stator geometry of a single-stage transonic fan was optimized to improve its aerodynamic performance and stall margin. Steady and unsteady simulations were conducted to analyze the impact of shock waves generated by the rotor blade on the stator inlet flow. Using a design of experiment and response surface method, an optimal geometry of the stator blade was obtained to increase the fan's efficiency and stall margin.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Yuanzhao Zhang, Bo Li
Summary: This study investigated the effects of longitudinal and lateral spacing on the aerodynamic drag characteristics of the whole team and each member in speed skating team pursuit competition. The results showed that decreasing the longitudinal spacing resulted in greater drag reduction for the whole team and individual skaters. Furthermore, lateral movement of the leading skater also led to additional drag reduction for the team. Computational fluid dynamics simulations revealed differences in drag distribution between the leading skater and the middle and last skaters.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sichang Xu, Chris Peirone, Eugene Ryzer, Gary W. Rankin
Summary: This paper presents a study of a special bistable load-type supersonic fluidic oscillator capable of producing self-sustained oscillations in two gas pressure chambers. The experimental portion verifies the robust nature of the device performance and shows distinct differences compared to a similar prototype. A three-dimensional computational fluid dynamics model is required to accurately simulate the transient filling process, leading to an unaffordable computational cost. To address this issue, a low-order fluid circuit model is developed, which provides an accurate and rapid prediction of the transient performance.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sampson Davis, Eli Shellabarger, James Miller, Thomas Ward
Summary: The present work focuses on studying the effects of shock wave - boundary layer interaction in 2D hypersonic flow at the sharp leading edge of a flat plate and a flat plate followed by a compression ramp. A key parameter, the hypersonic interaction parameter x, is defined and analyzed using a semi-analytic reduced-order model. The study aims to improve on existing methods by characterizing the viscous boundary layer and investigating the upstream influence resulting from the compression ramp.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
