The enhancement of an engine operability involves increasing the compressor surge margin which is still an open challenge.

The project FLORA (FLOw control in RAdial compressor) is twofold.

First, it proposes to achieve a comprehensive understanding of the transient behaviour of the radial compressor delivered by the Topic Leader through a precise characterization of the instabilities which develop at various rotation speeds and at different IGV (Inlet Guide Vanes) stagger angles. Detailed experimental investigations are planned providing an improved and time-resolved description of the path to surge.

Then, it proposes to apply passive flow control strategies in order to push back the compressor surge line towards low mass flow which will consequently enhance the compressor stability, hence the engine operability. The proposal particularly aims at evaluating the benefits from the boundary layer aspiration in radial geometries in terms of performance (gain in pressure ratio and efficiency) and surge margin. Besides experiments, calculations will help for the understanding of the internal flow structures which develop from stable operating points up to surge. High-fidelity Large Eddy Simulations (LES) will be used to get an in-depth comprehension of the impact of the flow control on the internal flow.

The project FLORA will contribute to the development of stable and efficient radial compressors with extended operating range.