This proposal addresses a pressing need for the industrial flow control applications: the development of active control methods adapted to broadband turbulence dynamics with limited number of actuators and sensors. We propose to develop a strategy based on dynamic least-order models and target robust and real-time controllers. Control shall be tested in experimental demonstrators. In this project, we focus on shear flows of industrial interest accessible to reduced-order modeling and closed-loop control. Turbulence control can often not directly suppress instabilities via linear control but relies on an exploitation of nonlinear mechanisms of the turbulence cascade. Mathematically, the effect of a single frequency on broadband dynamics constitutes a major challenge, both to modeling and control design. In principle, optimal control based on Navier-Stokes discretizations (white-box models) could provide control strategies. In practice, the large computational load prevents online capability in the foreseeable future. On the empirical side, currently identified black-box models can only predict the effect actuation and sensing at one discrete frequency, i.e. have to discard the enabling turbulence nonlinearities. We pursue semi-empirical reduced-order models (ROM) as a gray-box compromise between too expensive white-box and too inaccurate black-box models. Starting point is a reduced-order Galerkin method based on the proper orthogonal decomposition (POD) with associated control design. Our efforts will address current challenges of ROM-based control of turbulent shear flows specifically related to broad-band dynamics and to convection effects. One key enabler is a novel stochastic frequency-band model for the normal cascade and Reynolds stress effects, inspired by turbulence theory. Another key enabler are domain decomposition techniques for the inverse cascade and convection effects, adopting CFD methods. Three benchmark demonstrators are chosen among the configurations studied intensively in the Institute Pprime: coherent structure manipulation of a turbulent mixing layer, noise reduction of a turbulent jet and lift increase of an airfoil at high angle of attack. This research program will synergize expertises from Pprime on the experimental approaches and numerical modelling and from the author on reduced-order modelling for turbulence control including his network of international collaborators. These collaborations with the leading experts of modeling and flow control shall be continued and strengthened in the proposed international visitor program. This program constitutes a key point of our proposal. This form of collaboration is essential to find solutions to the inherently interdisciplinary turbulence control challenges. This program shall help to establish a leading-edge research group in closed-loop turbulence control targeting real-world industrial applications. Thus, internationally and interdisciplinary visible demonstrators for closed-loop turbulence control shall be established.

While the performance and learning of movement sequences has received a good bit of experimental attention, little if any focused attention has been directed at participants’ ability to observational practice and sequence learning. This is a critical practical issue because performers often observe the movement sequence that will be performed afterwards. Observational practice and sequence learning are also of considerable theoretical interest because observing how performers acquire a movement sequence without physical practice should provide valuable insights into the fundamental ways in which movement sequences are structured, stored, and executed. The primary purpose of the present proposal is to identify the conditions under which and the process by which observational practice improves movement sequence learning. These questions will be investigated in the first two experimental series. The second purpose is to record the eye movement during observation of a sequence performed by a model. We want to determine whether predictive eye movements are displayed during the observation of a sequence movement as displayed in visually guided actions. The question of eye movements will be investigated in experimental series 3

Global warming impacts the accessibility and the catch ability of fish prey in marine ecosystems. Predictive models indicate that the temperature of oceans will continue to increase in the next decades. This warming will result in the deepening of the thermocline, and increase of ocean stratification which is expected to reduce mixing processes. In addition, coupled to increasing concentration of CO2, dissolved oxygen at depth should decrease over the next decades. All these changes are expected to have substantial biological and economical consequences. Particularly, they will impact the horizontal and vertical distribution of marine resources and consequently the foraging efficiency of their natural predators and the yield of fisheries. However, the assessment of biological consequences related to climate change on marine ecosystems is clearly lacking and not easily predictable due to major uncertainties concerning the nature of the link and the mechanisms between physical and biological processes. Much research has been conducted over the last decades to address the subject of foraging efficiency of top marine predators in relation to oceanographic conditions. However, these studies were constrained by the limitations of existing techniques mainly providing a qualitative index of foraging success, but rarely a quantitative index. Recently, new technologies have resulted in the obtaining of extensive and high resolution oceanographic data sets and the development of new analyses methods. These technologies allows while studying the at sea behaviour of top predators, the collection of invaluable oceanographic parameters over large spatial scales. Whether this approach provide an unprecedented dataset to physically and biologically characterize the marine habitat of marine predators, the lack of in situ observations of the feeding events and the absence of information on prey distribution and abundance prevented to assess properly how the spatial change in oceanographic condition impacts the accessibility, the catch ability and consequently the foraging efficiency of the top marine predators. Understanding such processes is critical to build up predictions and model to properly assess the impact of oceanographic change on top air-breathing marine predators. The general aims of this project, is to implement accelerometers allowing to assess at high spatio-temporal resolution prey intake coupled with a new generation of loggers allowing for the fist time the recording of dissolved oxygen concentration. Using this approach we intend to assess spatio-temporal change in foraging success of elephant seals according to the heterogeneity of the oceanographic conditions encountered along the track and while diving. This task dedicated to observation represents a scientific and a technical challenge in a three dimensional environment still inaccessible. Moreover, predicting by modelling the response of individuals to environmental changes is of a crucial importance to better understand the effects on the whole population and represents currently an international concern. Therefore, the collected observations will be used in a second task dedicated to predictions as a natural experiment to better assess the likely consequences of a deepening thermocline and reduced oxygen concentration on the foraging efficiency of this deep diving predator. This post-doc will allow me to implement in France, new methods learnt while in post-doc in Canada and will provide an excellent opportunity to complete my training and to compete for research-teaching positions in France and Europe.