Periodic Reporting for period 3 - FLORA (FLOw control in RAdial compressor)
Période du rapport: 2021-09-01 au 2023-10-31
The FLORA (FLOw control in RAdial compressor) project aims at promoting the development of the next generation of aeronautical engines (weight reduction, increased efficiency and stability range) to reduce environmental impact of air transport (reducing emissions of CO2, NOx and noise impact). In such a context, the compressors are major components because they determine the fuel consumption, the stability range and the acceleration ability of the entire engine. The enhancement of an engine operability involves increasing the compressor surge margin which is still an open challenge. Thus FLORA project main goal is to contribute to extending the aeronautics centrifugal compressor operating range to more efficient operating zone.
From an aerodynamic point of view, that requires a better understanding of phenomena which limit the stability range and to develop strategies in order to widen it while keeping (even increasing) the performance at nominal operating condition.
FLORA project has two main objectives:
• First, it proposes to achieve a comprehensive understanding of the transient behaviour of the radial compressor delivered by Safran Helicopter Engines through a precise characterization of the instabilities which develop at various rotation speeds and at different Inlet Guide Vanes stagger angles. Detailed experimental investigations are planned providing an improved and time-resolved description of the path to surge (including unsteady pressure and LDV measurements).
• 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 project 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. Numerous (U)RANS and LES simulations will be used to get an in-depth comprehension of the impact of the flow control on the internal flow.
This project has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement N° 820099.
From an aerodynamic point of view, that requires a better understanding of phenomena which limit the stability range and to develop strategies in order to widen it while keeping (even increasing) the performance at nominal operating condition.
FLORA project has two main objectives:
• First, it proposes to achieve a comprehensive understanding of the transient behaviour of the radial compressor delivered by Safran Helicopter Engines through a precise characterization of the instabilities which develop at various rotation speeds and at different Inlet Guide Vanes stagger angles. Detailed experimental investigations are planned providing an improved and time-resolved description of the path to surge (including unsteady pressure and LDV measurements).
• 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 project 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. Numerous (U)RANS and LES simulations will be used to get an in-depth comprehension of the impact of the flow control on the internal flow.
This project has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement N° 820099.
For the first period numerous actions were conducted with success including:
• The adaptation of the compressor module on the ECL 1 MW test rig.
• Performance measurements and unsteady pressure measurements on a large range of operating condition (various IGV stagger angle and rotation speed).
• RANS calculation on a large range of operating condition (various IGV stagger angle and rotation speed).
• LES calculation at nominal speed.
• Publication of the first analysis of experimental results in a Journal paper.
For the second period numerous actions were conducted with success including:
• RANS Compressor map completed with a third IGV stagger angle.
• URANS calculations: 800 rotations on 20 operating point.
• Development of LES calculation with aspiration methodology at nominal speed.
• Publication of a Journal paper and two conference publication.
For the final period, numerous successful actions were conducted, including:
• Performance measurements and unsteady pressure measurements with flow control (air suction) at low and intermediate speeds.
• Internal flow measurement using an optical measurement method (LDA).
• Characterization of the various instabilities.
• Analysis of the effect of IGV stagger.
• Analysis of the effect of flow control.
• Creation and dissemination of project databases.
• Publication of three Journal papers and two conference publications.
• Successful defense of a thesis.
• The adaptation of the compressor module on the ECL 1 MW test rig.
• Performance measurements and unsteady pressure measurements on a large range of operating condition (various IGV stagger angle and rotation speed).
• RANS calculation on a large range of operating condition (various IGV stagger angle and rotation speed).
• LES calculation at nominal speed.
• Publication of the first analysis of experimental results in a Journal paper.
For the second period numerous actions were conducted with success including:
• RANS Compressor map completed with a third IGV stagger angle.
• URANS calculations: 800 rotations on 20 operating point.
• Development of LES calculation with aspiration methodology at nominal speed.
• Publication of a Journal paper and two conference publication.
For the final period, numerous successful actions were conducted, including:
• Performance measurements and unsteady pressure measurements with flow control (air suction) at low and intermediate speeds.
• Internal flow measurement using an optical measurement method (LDA).
• Characterization of the various instabilities.
• Analysis of the effect of IGV stagger.
• Analysis of the effect of flow control.
• Creation and dissemination of project databases.
• Publication of three Journal papers and two conference publications.
• Successful defense of a thesis.
To summarize, the following general advancements in knowledge related to process innovations were produced within the framework of the FLORA project:
• Improvement of expertise in experimental approaches for investigating internal flows in turbomachinery.
• Enhancement of optical measurements.
• Advancement of expertise in high-fidelity simulations in the context of turbomachinery.
• In-depth validation of numerical predictions and associated models.
• Understanding of flow organization and unsteadiness leading to surge and flow instabilities.
• Precise and detailed understanding of the transient behavior of the SHE radial compressor.
• Enhancement of flow control strategy to extend the high-efficiency operating range.
• Improvement of expertise in experimental approaches for investigating internal flows in turbomachinery.
• Enhancement of optical measurements.
• Advancement of expertise in high-fidelity simulations in the context of turbomachinery.
• In-depth validation of numerical predictions and associated models.
• Understanding of flow organization and unsteadiness leading to surge and flow instabilities.
• Precise and detailed understanding of the transient behavior of the SHE radial compressor.
• Enhancement of flow control strategy to extend the high-efficiency operating range.