Search results for "FLUID"
showing 10 items of 5513 documents
Demo 70. Turbulencia
2013
Objetivos: Comprender la utilizad del número de Reynolds para predecir la ocurrencia de turbulencia.
Nonlinear evolution equations for turbulent superfluids
2010
In this paper a system of evolution equations for turbulent superfluid helium is written in the nonlinear regime, choosing as fundamental fields the density, the velocity, the heat flux, the non-equilibrium temperature and the average vortex line density per unit volume. Approximate equations are written, where second order terms in the non-equilibrium quantities are retained.
Strictly correlated electrons approach to excitation energies of dissociating molecules
2019
In this work we consider a numerically solvable model of a two-electron diatomic molecule to study a recently proposed approximation based on the density functional theory of so-called strictly correlated electrons (SCE). We map out the full two-particle wave function for a wide range of bond distances and interaction strengths and obtain analytic results for the two-particle states and eigenenergies in various limits of strong and weak interactions, and in the limit of large bond distance. We then study the so-called Hartree-exchange-correlation (Hxc) kernel of time-dependent density functional theory which is a key ingredient in calculating excitation energies. We study an approximation b…
The two-fluid extended model of superfluid helium
2019
In this paper we perform the first numerical comparison between the two main existing models of superfluid helium: the two-fluid model proposed by Landau and the one-fluid extended model proposed from the extended thermodynamics. The numerical experiments in this paper regard the profiles of the so-called normal and superfluid components in 2D counterflow turbulence.
Constant sign and nodal solutions for parametric anisotropic $(p, 2)$-equations
2021
We consider an anisotropic ▫$(p, 2)$▫-equation, with a parametric and superlinear reaction term.Weshow that for all small values of the parameter the problem has at least five nontrivial smooth solutions, four with constant sign and the fifth nodal (sign-changing). The proofs use tools from critical point theory, truncation and comparison techniques, and critical groups. Spletna objava: 9. 9. 2021. Abstract. Bibliografija: str. 1076.
L'Atlante dei Waterfront. Visioni, paradigmi, politiche e progetti per i waterfront siciliani e maltesi
2013
Il volume contiene gli esiti del P.O. Italia-Malta "Waterfront" dedicato alla rigenerazione dei waterfront, applicata a casi di studio siciliani e maltesi
Progettare città liquide
2021
Urban waterfronts are today one of the most prolific variants of augmented cities: fluid and hybrid places where resources, opportunities, aspirations and ambitions of cities are translated into visions, new relations and projects. The creative port city is capable of reactivating new fluid metabolism, generating new architectural forms and producing new landscapes. The permanent flows of urban culture, grounding on the waterfront, are capable to fuel huge relational networks, making cities more dynamic, communicative and competitive. The most important implication of waterfront regeneration is that this particular area should be addressed as a structural and strategic element of the city a…
Numerical Simulations of the Flow Field of a Submerged Hydraulic Jump over Triangular Macroroughnesses
2021
The submerged hydraulic jump is a sudden change from the supercritical to subcritical flow, specified by strong turbulence, air entrainment and energy loss. Despite recent studies, hydraulic jump characteristics in smooth and rough beds, the turbulence, the mean velocity and the flow patterns in the cavity region of a submerged hydraulic jump in the rough beds, especially in the case of triangular macroroughnesses, are not completely understood. The objective of this paper was to numerically investigate via the FLOW-3D model the effects of triangular macroroughnesses on the characteristics of submerged jump, including the longitudinal profile of streamlines, flow patterns in the cavity regi…
Vertex corrections for positive-definite spectral functions of simple metals
2016
We present a systematic study of vertex corrections in the homogeneous electron gas at metallic densities. The vertex diagrams are built using a recently proposed positive-definite diagrammatic expansion for the spectral function. The vertex function not only provides corrections to the well known plasmon and particle-hole scatterings, but also gives rise to new physical processes such as generation of two plasmon excitations or the decay of the one-particle state into a two-particles-one-hole state. By an efficient Monte Carlo momentum integration we are able to show that the additional scattering channels are responsible for the bandwidth reduction observed in photoemission experiments on…
High-Reynolds-number turbulent cavity flow using the lattice Boltzmann method
2018
We present a boundary condition scheme for the lattice Boltzmann method that has significantly improved stability for modeling turbulent flows while maintaining excellent parallel scalability. Simulations of a three-dimensional lid-driven cavity flow are found to be stable up to the unprecedented Reynolds number $\mathrm{Re}=5\ifmmode\times\else\texttimes\fi{}{10}^{4}$ for this setup. Excellent agreement with energy balance equations, computational and experimental results are shown. We quantify rises in the production of turbulence and turbulent drag, and determine peak locations of turbulent production.