Isolation of the singular part of the electromagnetic field scatteredby objects with sharp edges and conic points

In this article we propose a method for overcoming a number of problems that may arise when solving scattering problems on objects of complex structure. This approach can be used for mathematical and numerical modeling of waveguide, emitting and scattering systems of various complexity.

Activities in the Secondary School

In this chapter there is the presentation of a vertical path on the main topics of arithmetic-algebra-infinitesimal calculus and numerical methods, which are an object of study in the secondary school. Naturally, the attention will be focused on the “virtual” phase, that is the applications with the computer and the MatCos 3.X environment, both as graphical-numerical experimentation, of intuitive support to the understanding of the concepts, that as a necessary moment for the actual calculation in the applications. It presents a TLS based on a real problem, from which the whole presented methodology shines through: from problem solving, to mathematical and numerical modeling, to the formulation of the solving algorithm and its implementation in the MatCos 3.X environment.

Interdependence of flow and pipe characteristics in transient induced contamination intrusion: numerical analysis

Contaminant intrusion in pipelines during transients is a remarkable mechanism, which leads to a decline in the quality of the contained water. The negative pressure of water hammer pressure waves is the trigger for the suction of pollution from the surrounding leak area, and hence deteriorating water quality. The volume of contamination intruded into the pipeline is investigated using mathematical and numerical modeling of the phenomenon. To elucidate this phenomenon in real pipe systems, the intrusion amount is estimated for 72 different scenarios including: two lengths of pipeline (i.e. short and long), three different leak locations, three different fluid velocities in the pipe, two leak diameters and two pipeline materials (elastic and viscoelastic). The results showed that the amount of intrusion in viscoelastic pipes was clearly less than that in elastic pipes, especially in long pipelines. The critical zone of high intrusion risk is identified close to the downstream valve for small leak sizes, nevertheless, it is difficult to estimate this zone in the case of large leaks due to significant interactions between nodal components (valve, leak, reservoir).

NUMERICAL SOLUTION OF BLOOD DYNAMICS IN ATHEROSCLEROTIC CAROTIDS

In this work we present the mathematical and numerical modeling of blood fluid-dynamics in atherosclerotic carotids. We review how to obtain the computational domain, the mathematical formulation of the fluid-structure interaction problem, and a possible strategy for its numerical discretization. We also report some numerical results for a case both before and after the surgical removal of the plaque.