Objectives

The PHARE experimental facility will permit each of the partners to carry out scientific works that were previously out of reach for them. Indeed, the absence of experimental data relating to configurations of extreme situations prevents the construction of reliable numerical models. This new equipment will permit all the partners to better understand the physical mechanisms generated during mechanical and aerodynamic instability, rupture processes and any other phenomenon leading to abnormal behaviour. Since the experimental facility has been designed for realistic turbomachines, it will provide directly usable data for situations in which these machines are used.

The experimental facility will therefore provide data to all the numerical codes being developed by each of the partners, and it will encourage setting up innovative projects based on two main orientations: reducing the level of consumption (a major stake for the coming decades), and controlling environmental risks.
Indeed, the first orientation will permit the partners to develop via a multidisciplinary approach new architectures for turbomachines with low energy consumption that combine new materials (composites, ceramics, polymers, etc.), mechatronic approaches (piezoelectric control, flow control, etc.), new geometries, better inclusion of aeroelastic phenomena, etc.

The second orientation, relating to controlling environmental risks and the reliability of solutions, is also of great importance since it involves human and material safety, and environmental impacts. The extreme optimisation of machines leads us to examine risk situations more closely: narrowing tolerances (rotor-stator contact), lightening structures (greater flexibility of devices permitting dynamic and aeroelastic couplings), higher aerodynamic loading and more compact machines (aerodynamic instability, risk of rupture). In addition, the race to gigantism observed in particular in nuclear energy production and the refitting of existing plants with more efficient (and thus more massive) equipment leads to increase the destructive effects of failures. It is therefore necessary, through time, to be capable of numerically simulating all these mechanical situations, which presupposes genuine progress in the development of current simulation software. Although some solutions exist that favour reduced consumption, they may not only lead to risk prone dynamic states but also generate noise levels incompatible with environmental standards. For example, `open rotor` type architecture will lead to considerable reduction of consumption levels, but generate unacceptable noise. Likewise, the interaction between flows and pods (for aircraft, wind turbines) can be a source of acoustic radiation that exceeds current standards. The aim is therefore to identify strategies of reducing passive noise by using new materials with microstructural characteristics, by adapted geometries, and by using active resources capable of controlling the onset of instabilities and the level of acoustic radiation.