Research objectives and content
This project aims to study monotonic and oscillatory thermocapillary instabilities in fluid layers (Marangoni-Benard flows). As the vast majority of works on the subject treat about linear and weakly nonlinear situations, our main goal to achieve a description of strongly nonlinear regimes, more frequently observed in experiments (e.g. evaporative convection). First, Ginzburg-Landau equations for hexagonal, roll or square steady patterns will be extrapolated as models for describing defects and transitions experimentally observed at moderate supercriticalities. Complex Ginzburg- Landau equations will be derived from basic equations to study bifurcations of wave patterns and resonant wave interactions. Then, strongly nonlinear regimes will be studied: for monotonic instabilities, a model developed earlier and displaying transitions to chaotic flows (boundary-layer secondary instability) will be exploited, both to develop low- dimensional Lorenz-like models, and to study statistical properties of turbulent regimes. The role of fastest growing modes and of generic features such as bulk temperature field homogenisation, small-scale generation, energy pumping from basic gradient and thermal dissipation will be identified. Such kind of models will also be developed for oscillatory instabilities, and confronted to full simulations and experiments. Training content (objective, benefit and expected impact)
Available resources and post-doc training capabilities of IP-UCM will significantly increase the scientific potential the applicant and of other researchers at both Madrid and Brussels laboratories, in addition to increased synergy, long- term collaboration, post-doc exchanges, and coordination of objectives.
Links with industry / industrial relevance (22)
None at the moment.