Results 21 to 30 of about 26,029 (108)

Space‐Time Modeling and Numerical Simulations of Non‐Newtonian Fluids Using Internal Variables

International Journal for Numerical Methods in Fluids, EarlyView.
Based on Hamilton's principle, the study focuses on a novel strategy for the modeling of non‐Newtonian fluids with the help of internal variables. Here, the viscosity evolves locally in space and time. Three configurations are numerically implemented, namely channel flow, a benchmark, and a lid‐driven cavity.
Philipp Junker, Thomas Wick
wiley   +1 more source

Fast derivatives of likelihood functionals for ODE based models using adjoint-state method

, 2017
We consider time series data modeled by ordinary differential equations (ODEs), widespread models in physics, chemistry, biology and science in general.
Haber, Tom, Melicher, Valdemar, Vanroose, Wim   +2 more
core   +1 more source

On the Behavior of Two C1 Finite Elements Versus Anisotropic Diffusion

International Journal for Numerical Methods in Fluids, EarlyView.
Bi‐cubic Hemite‐Bézier and reduced cubic Hsieh‐Clough‐Tocher finite elements, of class C1, are compared for the solution of a highly anisotropic diffusion equation. They are tested numerically for various ratios of the diffusion coefficients on different meshes, even aligned with the anisotropy.
Blaise Faugeras, Hervé Guillard, Boniface Nkonga, Francesca Rapetti   +3 more
wiley   +1 more source

Reductions of Gauss-Codazzi equations

, 2016
We prove that conformally parametrized surfaces in Euclidean space $\Rcubec$ of curvature $c$ admit a symmetry reduction of their Gauss-Codazzi equations whose general solution is expressed with the sixth Painlev\'e function.
Conte, Robert, Grundland, A. Michel
core   +1 more source

The Logistic Function in Glass Transition Models of Amorphous Polymers: II. A Theoretical Framework for Isothermal Compression Processes

Macromolecular Theory and Simulations, EarlyView.
An exactly‐solvable Riccati equation that approximates the macroscopic‐phenomenological behavior of amorphous polymers at glass transition pressure, Pg${P}_{g}$, is derived within thermodynamics with internal state variables. This work confirms the validity of the logistic function in glass transition models of amorphous polymers and establishes a ...
Claudio Corbisieri
wiley   +1 more source

On the analyzing of bifurcation properties of the one‐dimensional Mackey–Glass model by using a generalized approach

Mathematical Methods in the Applied Sciences, EarlyView.
The goal of this work is to look at how a nonlinear model describes hematopoiesis and its complexities utilizing commonly used techniques with historical and material links. Based on time delay, the Mackey–Glass model is explored in two instances. To offer a range, the relevance of the parameter impacting stability (bifurcation) is recorded.
Shuai Zhang, Yaya Wang, Hongyin Geng, Wei Gao, Esin Ilhan, Haci Mehmet Baskonus   +5 more
wiley   +1 more source

BRST analysis of general mechanical systems

, 2013
We study the groups of local BRST cohomology associated to the general systems of ordinary differential equations, not necessarily Lagrangian or Hamiltonian.
A.A. Sharapov, Agrachev, Alexandrov, Barnich, Barnich, Barnich, Barnich, Barnich, Barnich, Batalin, Cattaneo, D.S. Kaparulin, Fuchs, Grigoriev, Henneaux, Henneaux, Kaparulin, Kaparulin, Kazinski, Kosmann-Schwarzbach, Lada, Lyakhovich, Lyakhovich, Lyakhovich, Lyakhovich, Maclane, Retakh, S.L. Lyakhovich, Seiler, Voronov   +29 more
core   +1 more source

A Geometric Interpretation for the Algebraic Properties of Second‐Order Ordinary Differential Equations

Mathematical Methods in the Applied Sciences, Volume 48, Issue 6, Page 6912-6917, April 2025.
ABSTRACT Nowadays, a substantial portion of investigations concerning the symmetry analysis of differential equations predominantly adhere to a framework comprising the following key procedures: (i) the derivation of symmetries, (ii) the determination of an optimal system, (iii) the utilization of these symmetries to construct invariants or ...
A. Paliathanasis, S. Moyo, P. G. L. Leach   +2 more
wiley   +1 more source

Unveiling New Perspectives on the Hirota–Maccari System With Multiplicative White Noise

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT In this study, we delve into the stochastic Hirota–Maccari system, which is subjected to multiplicative noise according to the Itô sense. The stochastic Hirota–Maccari system is significant for its ability to accurately model how stochastic affects nonlinear wave propagation, providing valuable insights into complex systems like fluid dynamics
Mohamed E. M. Alngar, Khaled A. Gepreel, Reham M. A. Shohib, Yakup Yildirim   +3 more
wiley   +1 more source

Quasilinear Degenerate Evolution Systems Modelling Biofilm Growth: Well‐Posedness and Qualitative Properties

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We analyze nonlinear degenerate coupled partial differential equation (PDE)‐PDE and PDE‐ordinary differential equation (ODE) systems that arise, for example, in the modelling of biofilm growth. One of the equations, describing the evolution of a biomass density, exhibits degenerate and singular diffusion.
K. Mitra, S. Sonner
wiley   +1 more source