COT · Control of Turbulence
7РП — „Хора“ (Действия „Мария Кюри“)
- Период
- 2010-10-01 → 2013-09-30
- Финансиране от ЕС
- 45 000 €
- Участници
- 1
- Схема
- MC-ERG
Линиите свързват координатора с партньорите.
Накратко на български
Турбулентността на течностите и газовете се анализира чрез математически модели, за да се разбере как се появяват хаотичните потоци при стените на обектите. Това помага за намаляване на разхода на гориво и вредните емисии при движение на превозни средства.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Control of Turbulence
The work carried out by the fellow in the course of the ERG grant was of numerical type. The fellow used a spectral collocation technique to identify new nonlinear solutions of the Navier-Stokes equations for boundary layer flows, solutions believed to hold a significant role in the transition to turbulence. The approach which eventually proved successful in identifying such new solutions relied on a flow-structure-regeneration-process known as the SSP (self-sustaining process). These flow states form the backbone around which turbulence is organised and maintained near a wall. They also provide clues on the origins of turbulence, i.e. on the transition process. Clearly, a turbulent flow is more dissipative than a corresponding laminar flow at the same speed; this results in more energy being spent to move any vehicle within a fluid which behaves chaotically. It is thus of importance to find means to mitigate turbulence or delay its onset, in order to reduce fuel consumption and emissions. The second part of the fellow's work thus focussed on a flow control approach, wall suction, which is being widely studied, for example in the aeronautics community, for its capacity to delay the onset of transition. The effect of suction onto the birth of nonlinear travelling wave solutions was studied by the fellow with a technique similar to that used previously. Dr. Wedin was able to demonstrate that nonlinear solutions could find their onset only at much larger values of the Reynolds number (thus at much larger fluid speeds) as compared to the conventional boundary layer flow without suction. This proves indirectly the capacity of this flow control technique to address successfully the goal of transition delay. The study pursued paves the way for many further studies, of both theoretical and more applied nature.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
The applicant researcher will do numerical studies to understand how to control or delay turbulence in boundary layer flows. This will be mainly carried out by Direct Numerical Simulations (DNS) of the Navier-Stokes equations. To initiate the DNS we intend to use, as initial conditions, the nonlinear travelling wave solutions (TWS) for the boundary layer flow that the applicant discovered during his IE-fellowship, which served as an initial phase of a long-term plan of understanding turbulence. The TWS are suitable initial conditions which have been suggested to be crucial for the understanding of turbulence and for its control. They are also important since they have stable manifolds but also a few unstable manifolds whose trajectories usually relaminarise or go turbulent. The aim is to consider a mode that sits on the unstable manifold as an initial condition and force the resulting flow trajectory to revert to laminar rather than turbulence using control strategies.The main idea of the proposed research is to use ideas from Nature and mimic the behaviour of plants and animals in order to develop ideas on how to control turbulence. Various strategies are planned to be studied to realise their suitability. The major goal is to produce clear steps forward in this branch of turbulent research.In terms of achievements the outcome of the research will be several research papers disseminated in leading international journals; furthermore and more importantly, the research will pave the way for ideas on how to manipulate turbulence in the laboratory and in industrial applications.The proposed research suits well with current research at the University of Genova and goes along the line of the fellow’s aspirations and academic interests. At the University of Genova the applicant researcher will find the ideal environment to develop and broaden further his scientific skills in fluid mechanics, stability theory, control, biomimicry and parallel computing.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITA DEGLI STUDI DI GENOVA · GENOVAКоординаторИталия
Връзки
Данни: CORDIS, © Европейски съюз