Displaying 21 – 40 of 42

Showing per page

Modelling of Natural Convection Flows with Large Temperature Differences: A Benchmark Problem for Low Mach Number Solvers. Part 2. Contributions to the June 2004 conference

Henri Paillère, Patrick Le Quéré, Catherine Weisman, Jan Vierendeels, Erik Dick, Malte Braack, Frédéric Dabbene, Alberto Beccantini, Etienne Studer, Thibaud Kloczko, Christophe Corre, Vincent Heuveline, Masoud Darbandi, Seyed Farid Hosseinizadeh (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

In the second part of the paper, we compare the solutions produced in the framework of the conference “Mathematical and numerical aspects of low Mach number flows” organized by INRIA and MAB in Porquerolles, June 2004, to the reference solutions described in Part 1. We make some recommendations on how to produce good quality solutions, and list a number of pitfalls to be avoided.

Modelling of Natural Convection Flows with Large Temperature Differences: A Benchmark Problem for Low Mach Number Solvers. Part 1. Reference Solutions

Patrick Le Quéré, Catherine Weisman, Henri Paillère, Jan Vierendeels, Erik Dick, Roland Becker, Malte Braack, James Locke (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

There are very few reference solutions in the literature on non-Boussinesq natural convection flows. We propose here a test case problem which extends the well-known De Vahl Davis differentially heated square cavity problem to the case of large temperature differences for which the Boussinesq approximation is no longer valid. The paper is split in two parts: in this first part, we propose as yet unpublished reference solutions for cases characterized by a non-dimensional temperature difference...

On the Charney Conjecture of Data Assimilation Employing Temperature Measurements Alone: The Paradigm of 3D Planetary Geostrophic Model

Aseel Farhat, Evelyn Lunasin, Edriss S. Titi (2016)

Mathematics of Climate and Weather Forecasting

Analyzing the validity and success of a data assimilation algorithmwhen some state variable observations are not available is an important problem in meteorology and engineering. We present an improved data assimilation algorithm for recovering the exact full reference solution (i.e. the velocity and temperature) of the 3D Planetary Geostrophic model, at an exponential rate in time, by employing coarse spatial mesh observations of the temperature alone. This provides, in the case of this paradigm,...

Optimal Convective Heat-Transport

Josef Dalík, Oto Přibyl (2011)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

The one-dimensional steady-state convection-diffusion problem for the unknown temperature y ( x ) of a medium entering the interval ( a , b ) with the temperature y min and flowing with a positive velocity v ( x ) is studied. The medium is being heated with an intensity corresponding to y max - y ( x ) for a constant y max > y min . We are looking for a velocity v ( x ) with a given average such that the outflow temperature y ( b ) is maximal and discuss the influence of the boundary condition at the point b on the “maximizing” function v ( x ) .

Population Growth and Persistence in a Heterogeneous Environment: the Role of Diffusion and Advection

A. B. Ryabov, B. Blasius (2008)

Mathematical Modelling of Natural Phenomena

The spatio-temporal dynamics of a population present one of the most fascinating aspects and challenges for ecological modelling. In this article we review some simple mathematical models, based on one dimensional reaction-diffusion-advection equations, for the growth of a population on a heterogeneous habitat. Considering a number of models of increasing complexity we investigate the often contrary roles of advection and diffusion for the persistence of the population. When it is possible we demonstrate...

Some properties of forced, dissipative large-scale circulations in a barotropic, non-divergent rotating atmosphere

Laura Gardini, Renzo Lupini, Carlo Pellacani (1983)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Viene studiata la stabilità dell’atmosfera in un pianeta ruotante, forzata da un agente esterno ed in presenza di dissipazione. Lo studio vien condotto nelle ipotesi barotropiche e riguarda, per l’effetto delle approssimazioni adottate, solamente quei fenomeni caratterizzati da grandi scale spaziali. In particolare viene studiata la stabilità dei flussi zonali che caratterizzano la circolazione dei maggiori pianeti del sistema solare; ne vengono determinate, servendosi della approssimazione di Galerkin,...

Currently displaying 21 – 40 of 42