A numerical approach known as fading regularization based on an inverse method has been developed to identify boundary conditions from field measurements by digital image correlation. The stress distribution along the boundary where a loading is applied allows to obtain an equivalent stiffness modulus of the studied material. The identified material parameters provide only a macroscopic response of the 2D structure since the postulated linear behaviour law is that of a homogeneous material. The objective of this project is to extend this work to three-dimensional field measurements representing the displacements of a possible heterogeneous material that follows a complex behaviour law. The extension of this approach would make it possible to answer to cellular biomechanical problems concerning the interactions between an invasive glioblastoma cancer cell and its microenvironment. For adults, glioblastomas are the most common and malignant primary brain tumours characterised by the presence of invasive cells in the periphery that are capable of disseminating into the surrounding brain tissue. The ability of glioblastoma cells to infiltrate brain tissue within the extracellular matrix (ECM) has been associated with the formation of invadopodia. The process of tumour invasion and the behaviour of such structures must therefore be addressed by both a biochemical and biomechanical approach. Biochemistry would allow the identification of the molecules involved and biomechanics would allow the quantification and analysis of their mechanical impacts. The aim of this project is to develop a new identification method based on an inverse method in order to study the process of invadopodia formation and to quantify the mechanical fields necessary for their invasion into the ECM. Due to the lack of information at the cell-ECM interface, the mathematical problem representing cell growth through invadopodia formation is an ill-posed problem.

The global circulation is a critical regulator of the Earth's climate processes that can be affected by the overall ocean energetics. How internal waves transport and transfer turbulent kinetic energy into mean flow potential energy is therefore a key process in the ocean. Naturally occurring double-diffusive convection can lead to the formation of spatially periodic density profiles called thermohaline staircases. Drawing analogies with condensed matter physics, this project will identify the physical mechanisms that govern internal wave transport in periodically stratified environments. The first work-package will focus on internal wave band gaps and the formation of surface states. We will then investigate the consequences of Coriolis forces on the wave propagation in periodic stratifications. The third work-package will examine the influence of spatial disorder in the periodicity of the density profile. The final part will focus on energy transfer by turbulent mixing and interactions with mean flows, as well as feedback processes emerging from mixing induced stratification evolution and external vortex flows similar to the eddies found in the ocean.

The project ImClean focuses on three main scientific challenges, aiming to improve the specific cooling capacity of thermoacoustic refrigerators that represent a green alternative to conventional refrigeration systems. The first challenge is to investigate experimentally and numerically the acoustic energy losses due to the transition to turbulence in acoustically oscillating flows. An experimental method based on coupled laser velocimetry and microphone measurements will be developed to quantify the acoustic loss due to the change in the flow regime. Also, numerical simulations will be performed and compared with the experimental results. This comparison will help in both deepening the understanding of the mechanism of acoustic energy loss and validating the proposed numerical models. The second challenge is studying the effects of flow discontinuities on acoustic energy losses and providing empirical correlations describing such effects. The developed experimental method for measuring the acoustic energy losses will be utilized to study the effects of flow discontinuities. CFD simulations will also be carried out to study the oscillating flow characteristics around these flow discontinuities. The results of the simulations will be compared with the experimental results to shed light on the physics of such losses. The outcomes of the proposed activities on the first two challenges will be very useful not only in defining the different losses that occur in thermoacoustic systems when operating at high acoustic levels (i.e. for high cooling capacity) but also for other medical and engineering applications. The last challenge is developing a compact and symmetric acoustic source for thermoacoustic applications. Developing such an acoustic source will reduce the total volume of the thermoacoustic refrigerator, hence improving its specific cooling capacity. A double-acting acoustic source will be designed and fabricated, and its performance parameters will be measured.

Turbulent flows dictate the performance characteristics of numerous industrial equipment and environmental applications. Wall-bounded flows have been extensively investigated for over two centuries, however our knowledge still pitiful modest, and this is even more true for practical flows. At low Reynolds number, turbulent boundary layers are populated by near-wall small-scales structure, by increasing the mixing momentum they increase the drag. Their effect on the drag has been well-documented and efficient control strategies designed. One key objective is to investigate their effect on heat transfer and if the similar control strategies could be applied for enhancing heat transfer. It is now well known that as the Reynolds number increases, larger structures appear in the outer flow and alter the structures near the wall, causing control to become rapidly ineffective. The ultimate goal of this research programme is to introduce a low-order dynamical model for predicting the effects of Reynolds number on canonical and actuated flow, in the aim to design the most effective strategies for drag reduction and heat transfer.

Problems involving the complex interactions of plasmas with fluids and solids have expanded in scope in recent years in part because of increased interest in low-temperature atmospheric-pressure plasmas (APP). Progress in APP-interface research can be advanced in several respects. First, direct microscopic study of the plasma interface could clarify the current understanding that is mostly inferred from macroscopic effects. Second, although plasma-fluid and plasma-surface interactions are often studied separately, new insights could emerge from studying the link between them, i.e. plasma-fluid-surface interaction. Third, novel phenomena at plasma interfaces could arise if advanced materials were used instead of bulk dielectric materials as surfaces for discharge propagation. PLASMAFACE aims to address these issues by developing advanced materials and surface processes that lead to new flow phenomena. The conventional paradigm of research in APP interactions with solids/fluids confers primary status to the plasma, which acts upon a surface or fluid. The vision behind this project is to change the point of view, wherein the plasma plays a supporting role as the facilitator of the relationship between the surface and the fluid. The principal object is in fact the surface, whose materials and processes we can manipulate to affect the fluid via the plasma. Two original APP sources will be developed to achieve this objective: nanosecond repetitively pulsed microplasma surface discharges and nanostructured surface discharges. Studies will be carried out in atmospheric pressure air and at room temperature using discharges generated on solid dielectric surfaces. Experiments to provide quantitative measurements of plasma properties, fluid velocity fields, and surface properties are proposed, acquired using in-situ time- and/or space-resolved diagnostics including electrical measurements, spectroscopy, and flow field visualization, as well as ex-situ materials characterization. The use of microspectroscopy is emphasized for detailed analysis of the interface. Coupling between gas discharge physics, hydrodynamics, surface processes, and nanoscale physics is expected to result in the emergence of interface phenomena such as the amplification of electrohydrodynamic effects and enhanced plasma propagation along surfaces. The results are expected to be generally useful to APP applications, but the study is primarily oriented towards future opportunities in aerodynamic flow control and nanomaterials processing.