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We investigated the pressure-driven flow in curved channels at low aspect ratio, the latter being the ratio between the channel height (along the axial direction) and width (along the radial direction). The dynamics was studied numerically,…

Fluid Dynamics · Physics 2026-03-03 Ezzahrae Jaafari , Pascale Magaud , Micheline Abbas

We study the motion of an interface between two irrotational, incompressible fluids, with elastic bending forces present; this is the hydroelastic wave problem. We prove a global bifurcation theorem for the existence of families of…

Analysis of PDEs · Mathematics 2025-08-19 Benjamin F. Akers , David M. Ambrose , Davia W. Sulon

The existence of local, classical solutions is proved, for a system of two coupled equations that describe, in the framework of the wave turbulence theory, the fluctuations around an equilibrium, of a system of nonlinear waves satisfying…

Analysis of PDEs · Mathematics 2025-05-02 Miguel Escobedo

We study the stability of coherent structures in plane Couette flow against long-wavelength perturbations in wide domains that cover several pairs of coherent structures. For one and two pairs of vortices, the states retain the stability…

Fluid Dynamics · Physics 2014-04-10 Konstantin Melnikov , Tobias Kreilos , Bruno Eckhardt

A numerical framework for rigorous linear stability analysis of two-phase stratified flows of two immiscible fluids in horizontal circular pipes is presented. For the first time, three-dimensional disturbances, including those at the…

Fluid Dynamics · Physics 2023-07-17 Ilya Barmak , Alexander Gelfgat , Neima Brauner

This paper considers two-dimensional steady solitary waves with constant vorticity propagating under the influence of gravity over an impermeable flat bed. Unlike in previous works on solitary waves, we allow for both internal stagnation…

Analysis of PDEs · Mathematics 2021-10-12 Susanna V. Haziot , Miles. H. Wheeler

This article discusses the description of wall-bounded turbulence as a deterministic high-dimensional dynamical system of interacting coherent structures, defined as eddies with enough internal dynamics to behave relatively autonomously…

Fluid Dynamics · Physics 2018-03-20 Javier Jimenez

A three-layer asymptotic structure for turbulent pipe flow is proposed, revealing in terms of intermediate variables, the existence of a Reynolds-number invariant logarithmic region. It provides a theoretical foundation for addressing…

Fluid Dynamics · Physics 2021-07-01 Sourabh S. Diwan , Jonathan F. Morrison

We derive necessary conditions that traveling wave solutions of the Navier-Stokes equations must satisfy in the pipe, Couette, and channel flow geometries. Some conditions are exact and must hold for any traveling wave solution irrespective…

Fluid Dynamics · Physics 2015-05-13 Y. Charles Li , Divakar Viswanath

The moving-contact line between a fluid, liquid and a solid is a ubiquitous phenomenon, and determining the maximum speed at which a liquid can wet/dewet a solid is a practically important problem. Using continuum models, previous studies…

Fluid Dynamics · Physics 2022-08-17 J. S. Keeler , D. A. Lockerby , S. Kumar , J. E. Sprittles

The laminar-turbulent boundary S is the set separating initial conditions which relaminarise uneventfully from those which become turbulent. Phase space trajectories on this hypersurface in cylindrical pipe flow look to be chaotic and show…

Fluid Dynamics · Physics 2015-05-13 Yohann Duguet , Ashley P. Willis , Rich R. Kerswell

We consider three-dimensional inviscid irrotational flow in a two layer fluid under the effects of gravity and surface tension, where the upper fluid is bounded above by a rigid lid and the lower fluid is bounded below by a flat bottom. We…

Analysis of PDEs · Mathematics 2019-07-24 Dag Nilsson

In this paper, we characterize a class of solutions to the unsteady 2-dimensional flow of a van der Waals fluid involving shock waves, and derive an asymptotic amplitude equation exhibiting quadratic and cubic nonlinearities including…

Mathematical Physics · Physics 2017-10-11 Neelam Gupta , V. D. Sharma

The recent theoretical discovery of finite-amplitude travelling waves in pipe flow has re-ignited interest in the transitional phenomena that Osborne Reynolds studied 125 years ago. Despite all being unstable, these waves are providing…

Fluid Dynamics · Physics 2009-11-13 C. C. T. Pringle , Y. Duguet , R. R. Kerswell

This paper studies the structural implications of constant vorticity for steady three-dimensional internal water waves. It is known that in many physical regimes, water waves beneath vacuum that have constant vorticity are necessarily two…

Analysis of PDEs · Mathematics 2023-08-09 Robin Ming Chen , Lili Fan , Samuel Walsh , Miles H. Wheeler

The existence and multiplicity of similarity solutions for the steady, incompressible and fully developed laminar flows in a uniformly porous channel with two permeable walls are investigated. We shall focus on the so-called asymmetric case…

Classical Analysis and ODEs · Mathematics 2018-04-18 Hongxia Guo , Changfeng Gui , Ping Lin , Mingfeng Zhao

Two-dimensional free-surface flow over localised topography is examined with the emphasis on the stability of hydraulic-fall solutions. A Gaussian topography profile is assumed with a positive or negative amplitude modelling a bump or a…

Fluid Dynamics · Physics 2024-03-12 Jack S. Keeler , Mark G. Blyth

Due to ample applications from medical services to industrial activities, the study of flow and heat transfer through a curved duct has attracted considerable attention to the researchers. In this paper, a comprehensive numerical study is…

Fluid Dynamics · Physics 2021-09-02 Selim Hussen , Mohammad Sanjeed Hasan , Mahtab Uddin , Rabindra Nath Mondal

We consider a two-dimensional, two-layer, incompressible, steady flow, with vorticity which is constant in each layer, in an infinite channel with rigid walls. The velocity is continuous across the interface, there is no surface tension or…

Analysis of PDEs · Mathematics 2023-10-18 Karsten Matthies , Jonathan Sewell , Miles H. Wheeler

Incompressible Navier-Stokes equations in the spherical coordinates are solved using a pseudo-spectral method to simulate the problem of spherical Couette flow. The flow is investigated for a narrow gap ratio with only the inner sphere…

Fluid Dynamics · Physics 2024-10-10 Ananthu J. P. , Manjul Sharma , Sameen A. , Vinod Narayanan