Catálogo de publicaciones - libros

We focus on the inter-related roles of scale and heterogeneity of porous medium properties for fluid flow and contaminant transport in isothermal and non-isothermal multiphase systems across a range of scales. Multiscale network and macro-scale continuum models, and detailed laboratory experiments are used to support the investigation. We demonstrate the critical role of scale in determining the dominant forces in a porous medium system, the importance of heterogeneity across a range of scales, and the dominant role of block heterogeneities on macro-scale fluid flow and non-isothermal contaminant remediation. We give special attention to the numerical approximations of pressure-saturation-conductivity relations in heterogeneous systems, and we show the effects of interface approximation schemes on both the ability to resolve phenomena of concern and on the efficiency of the numerical simulator.

In this paper we analyse the unsteady expansion and contraction of a long, two-dimensional bubble confined between superheated or subcooled parallel plates, whose motion is driven by mass transfer between the liquid and the vapour.

Semi-Lagrangian techniques are proposed for animating water waves in realistic events. The two-dimensional shallow water equations are considered to model the motion of water flow and a second order time marching procedure which combines the characteristic method with a finite differencing discretization is used to integrate the model. Numerical results are carried out on a squared pool without and with obstacles. The obtained results show that our algorithm is robust, stable and highly accurate.

Models based on a filtered Poisson process are used for the flow of a river. The aim is to forecast the next peak value of the flow, given that another peak was observed not too long ago. The most realistic model is the one when the time between the successive peaks does have an exponential distribution, as it is often assumed. An application to the Delaware River, in the USA, is presented.

The robust Parallel Finite Element Method examined in [5] and [4]. It is an element-wise parallel iterative solution method based on a Red-Black domain decomposition. Convection-diffusion problems are solved in an optimal order for a method which makes use of not more than local communication. For the parallellism, the recent paper [8] shows that a near perfect load-balance can be obtained for two-dimensional problems. This paper proves that one of the conditions which is sufficient in the two-dimensional case, unexpectedly is not so for the three-dimensional case.

A mathematical model for the flow and solidification of a thin liquid film is briefly described. Typical results for ice accretion due to incoming rain droplets on a at surface and aerofoil are shown.

The optimal profile of turbine blades is crucial for the efficiency of modern powerplants. The applied SQP algorithms are based on gradient information.

A Finite Element Modified Method of Characteristics (FEMMOC) is proposed for numerical solution of the two-dimensional shallow water equations. The method is formulated and implemented for mean flow and hydraulics in the strait of Gibraltar. Preliminary results presented in this work show that the FEMMOC is able to provide stable, accurate and efficient solutions.

We discuss an algorithm for convection-diffusion equations with high activity areas which combines the Local Defect Correction technique with high order compact finite difference schemes.

Since steady-state nonlinear fluid sloshing in moving tanks is caused by a finite set of natural modes, approximate solutions of the original free boundary value problem can be found from a system of nonlinear ordinary differential equations (modal system) coupling time dependent amplitudes of these leading modes. We focus on two-dimensional flows in a rectangular tank. We present an extensive literature survey and examine bifurcations of periodic (steady-state) solutions of a single-dominant modal system derived by [1].