Добро пожаловать на регулярные семинары по актуальным темам исследований в области вычислительной механики!

Приглашённые лекторы из Сколтеха и других вузов выступают с докладами, чтобы познакомить студентов с текущими исследованиями и достижениями в различных областях современной механики жидкости и твёрдого тела, прикладной математики, вычислительной математики и промышленного применения механики. Студенты получают возможность узнать об актуальных проблемах механики у ведущих специалистов в области вычислительной механики.

Продолжительность доклада: 50 минут

Q&A: 10-15 минут

Семинары проводятся на английском языке.

Ведущий преподаватель: Аслан Касимов, доцент

Контакты: A.Kasimov@skoltech.ru

21 МАЯ, 14:00 | АНАЛИЗ БЕГУЩИХ ВОЛН ОДНОЙ УПРОЩЕННОЙ МОДЕЛИ ИЗ ТЕОРИИ ГОРЕНИЯ

Аудитория: R3-2009
Докладчик: Шамиль Магомедов, аспирант программы «Инженерные системы», Сколтех

The talk will focus on a discussion of an analogue model of combustion. It is part of the research devoted to the study of the deflagration-to-detonation (DDT) transition. The deflagration-to-detonation transition is a phenomenon in which the slow subsonic combustion of a mixture is suddenly transformed into a supersonic shock wave characterised by a sudden jump in pressure and temperature. Understanding the various mechanisms of DDT and being able to control it is important for a number of reasons, including explosion safety, the development of detonation engines and others.

Analogue models of reacting flows have been successful in predicting many qualitative features of combustion waves. However, the phenomenon of DDT has escaped such simplified treatment. The purpose of the present research is to investigate in more detail the properties of such an analogue model capable of predicting the transition from deflagration to detonation.

The traveling waves of the system are analysed using asymptotic methods in the limit of small dissipation and weak nonlinearity. The problem of constructing stationary solutions is also investigated numerically using the finite element method with an adaptive computational mesh. A qualitative agreement between the results of the numerical and asymptotic approaches is demonstrated.

28 МАЯ, 14:00 | ВОЛНЫ ГОРЕНИЯ В ПЕРИОДИЧЕСКИ НЕОДНОРОДНЫХ СРЕДАХ

Аудитория: R3-2009
Докладчик: Марьюш Сорока, аспирант программы «Инженерные системы», Сколтех

The problem of propagation of a one-dimensional combustion wave in a periodically inhomogeneous medium is considered. The problem is motivated by the phenomenon of regularization of detonation wave velocity oscillations discovered in recent studies on detonation in inhomogeneous mixtures. It is known that both detonation waves, and slow combustion waves, propagating in homogeneous media have complex nonlinear dynamics. In this case, the wave velocity can oscillate regularly or chaotically depending on the mixture parameters (for example, activation energy). The question of the influence of periodic external conditions on such oscillations is of scientific and practical interest.

The talk will focus on the phenomenon of regularization of the dynamics of a combustion wave as it moves in a periodically inhomogeneous medium. A model system of reaction-diffusion equations for dimensionless temperature T and fuel concentration C with Arrhenius kinetics of energy release is studied. We investigate how spatial heterogeneity in the initial concentration of the fuel, as well as in the heat loss coefficient, affects wave dynamics. The influence of these parameters on combustion wave dynamics is analyzed by numerically solving the system. The nature of the oscillations is seen to depend significantly on the inhomogeneity profiles.