The question of finite-time blowup of the 3D incompressible Euler equations is numerically investigated in a periodic cylinder with solid boundaries. Using rotational symmetry, the equations are discretized in the (2D) meridian plane on an adaptive (moving) mesh and is integrated in time with adaptively chosen time steps. The vorticity is observed to develop a ring-singularity on the solid boundary with a growth proportional to ∼(ts - t)(-2.46), where ts ∼ 0.0035056 is the estimated singularity time. A local analysis also suggests the existence of a self-similar blowup. The simulations stop at τ(2) = 0.003505 at which time the vorticity amplifies by more than (3 × 10(8))-fold and the maximum mesh resolution exceeds (3 × 10(12))(2). The vorticity vector is observed to maintain four significant digits throughout the computations.
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http://dx.doi.org/10.1073/pnas.1405238111 | DOI Listing |
ACS Omega
January 2025
State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China.
In waterflooding development of narrow channel reservoirs, the water cut rises quickly, and the reservoir becomes nearly fully flooded, yet oil recovery remains low. The narrow strip sand body and long-term water injection create a complex oil and water distribution, making it difficult to evaluate the degree of reservoir utilization during waterflooding. This paper establishes a practical streamline method to quantitatively characterize the waterflooding mobilization degree of narrow channel reservoirs.
View Article and Find Full Text PDFBMC Res Notes
January 2025
Department of Mathematics, Jimma University, Jimma, Ethiopia.
Objective: In this work, singularly perturbed time dependent delay parabolic convection-diffusion problem with Dirichlet boundary conditions is considered. The solution of this problem exhibits boundary layer at the right of special domain. In this layer the solution experiences steep gradients or oscillation so that traditional numerical methods may fail to provide smooth solutions.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Theoretical and Computational Physics Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India.
The orbital-free density functional theory (OF-DFT) based method is a convenient tool to carry out electronic structure calculations scaling almost linearly with the number of electrons. However, the main impediment in the application of this method is the unavailability of the accurate form for the non-interacting kinetic energy functional in terms of electron density. The Pauli kinetic energy functional is the unknown part of the kinetic energy functional, and the corresponding Pauli potential appears in the governing Euler equation.
View Article and Find Full Text PDFEntropy (Basel)
November 2024
Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague, Czech Republic.
We develop a hybrid classical-quantum method for solving the Lorenz system. We use the forward Euler method to discretize the system in time, transforming it into a system of equations. This set of equations is solved by using the Variational Quantum Linear Solver (VQLS) algorithm.
View Article and Find Full Text PDFPhys Rev E
November 2024
Ecole Centrale de Lyon, CNRS, Université Claude Bernard Lyon 1, INSA Lyon, LMFA, UMR5509, 69130 Ecully, France.
In this paper, using hydrodynamic entropy, we quantify multiscale disorder in Euler and hydrodynamic turbulence. These examples illustrate that the hydrodynamic entropy is not extensive because it is not proportional to the system size. Consequently, we cannot add hydrodynamic and thermodynamic entropies, which measure disorder at macroscopic and microscopic scales, respectively.
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