Periodic Reporting for period 3 - InnoSTAT (Innovative STATOR)
Période du rapport: 2022-10-01 au 2023-12-31
The reduction measures for engine related noise from the intake, but also for rearward radiation is highly targeted during the last 15 to 20 years. Most effort has been made in passive technologies for intake liner concepts, but also for the low noise design of fan and stator blades. From all the current available technologies a noise reduction related to engine sources by 6 dB can be expected, which is a big achievement, but still does not suffice to reach the goals.
Thus, a further refinement of possible technologies had to be re-opened, like in the case of innovative stator technology. The proposed work of InnoSTAT consisted in a systematic procedure, which was performed yet for considered OGV technologies. InnoSTAT was the first project where the activities are focused on the above process with the only goal of bringing at least 3 OGV concepts to demonstrator level at TRL3 on full scale. This has not been achieved yet in any other programme for one OGV concept. The project’s objectives were
• to define 5 novel low noise stator concept designs, to develop and test them on prototype level TRL2 to TRL3,
• to select and develop 3 novel stator concepts for further advanced design, characterisation and full 3D stator stage large-scale testing of 2 OGV stages to TRL4,
• to define, design and manufacture 1 demonstrator OGV at TRL3 on full-scale.
The project’s goal will be achieved in 3 major steps
• testing and improving the technologies 5 concepts on small- scale prototype level,
• down-selection of 3 technologies for further test of two of them on large-scale, each as a fully equipped stator stage, and
• 1 selected concept demonstrator to be manufactured and perform an integration study regarding engine environment.
This 51-months project with its ambitious goals requested 2,788 k€ in total. Its contribution to the noise reduction on ultra-advanced long-range and ultra-advanced short-/medium-range will be significant.
Thus, a further refinement of possible technologies had to be re-opened, like in the case of innovative stator technology. The proposed work of InnoSTAT consisted in a systematic procedure, which was performed yet for considered OGV technologies. InnoSTAT was the first project where the activities are focused on the above process with the only goal of bringing at least 3 OGV concepts to demonstrator level at TRL3 on full scale. This has not been achieved yet in any other programme for one OGV concept. The project’s objectives were
• to define 5 novel low noise stator concept designs, to develop and test them on prototype level TRL2 to TRL3,
• to select and develop 3 novel stator concepts for further advanced design, characterisation and full 3D stator stage large-scale testing of 2 OGV stages to TRL4,
• to define, design and manufacture 1 demonstrator OGV at TRL3 on full-scale.
The project’s goal will be achieved in 3 major steps
• testing and improving the technologies 5 concepts on small- scale prototype level,
• down-selection of 3 technologies for further test of two of them on large-scale, each as a fully equipped stator stage, and
• 1 selected concept demonstrator to be manufactured and perform an integration study regarding engine environment.
This 51-months project with its ambitious goals requested 2,788 k€ in total. Its contribution to the noise reduction on ultra-advanced long-range and ultra-advanced short-/medium-range will be significant.
Between M1 and M18 the focus was mainly on the appropriate specifications and the final selection of OGV concepts for prototype manufacturing and testing. This was done in a final technology review, which was performed to ensure that the right technologies will be used for the test campaign of WP3. Further specifications, like basic test setup definition, blade geometry, target frequencies and aerodynamic properties, were established and extensively documented. The detailed description of the technical requirements for the OGV prototypes was provided and the specifications for the configurations to be studied in the small-scale experimental campaign were also developed. A first preliminary design review meeting (PDR) took place in M17.
The period from M19 to M36 was focused to prepare the small-scale wind tunnel tests of WP3. Every prototype concept underwent a detailed design regarding InnoSTAT's specific wind tunnel setup. A final concept selection occurred in summer 2021 after a CDR. In total, 49 OGV – 5 prototype sets and 2 references - were manufactured until mid of January 2022 and tested together with the reference OGV until end of May 2022. Almost all of the 5 prototype concepts showed promising acoustic results. 2 of the prototype concepts reached TRL 2 and haven’t been selected for the next step. 3 concepts reached TRL 3 and passed the selection procedure, by including the most important acoustic metrics together with aerodynamic performance. The consortium's 3 concepts went into the next phase of InnoSTAT, the large-scale investigations of WP4.
After M37, the WP4 focused on re-designing and select the low-noise OGV for the large-scale test campaign at the PHARE-2 facility. After successful PDR and CDR, 2 full OGV stages were manufactured and tested, until November 2023 and during January 2024. The third concept will be manufactured in 2024 to be available for future activities (InnoSTAT’s legacy). The results from large-scale show very good effects, of course depending on the operation point. But the total acoustic power could be reduced by 5dB to 10dB, with some tonal reductions up to 13 dB*. The target TRL 4 was fully achieved at large-scale.
The definition, specification, mechanical design and manufacturing of a full-scale demonstrator was done in WP5, ending up at TRL 2-3.
Test activities were closely accompanied by high-fidelity numerical work of WP2.
Overall, InnoSTAT was successful by achieving all of its set objectives.
*É.Salze et al., “Noise reduction of aero-engines using innovative stators with leading edge features”, AIAA/CEAS Aeroacoustics Conference, 4-7 June 2024, Rome, Italy.
The period from M19 to M36 was focused to prepare the small-scale wind tunnel tests of WP3. Every prototype concept underwent a detailed design regarding InnoSTAT's specific wind tunnel setup. A final concept selection occurred in summer 2021 after a CDR. In total, 49 OGV – 5 prototype sets and 2 references - were manufactured until mid of January 2022 and tested together with the reference OGV until end of May 2022. Almost all of the 5 prototype concepts showed promising acoustic results. 2 of the prototype concepts reached TRL 2 and haven’t been selected for the next step. 3 concepts reached TRL 3 and passed the selection procedure, by including the most important acoustic metrics together with aerodynamic performance. The consortium's 3 concepts went into the next phase of InnoSTAT, the large-scale investigations of WP4.
After M37, the WP4 focused on re-designing and select the low-noise OGV for the large-scale test campaign at the PHARE-2 facility. After successful PDR and CDR, 2 full OGV stages were manufactured and tested, until November 2023 and during January 2024. The third concept will be manufactured in 2024 to be available for future activities (InnoSTAT’s legacy). The results from large-scale show very good effects, of course depending on the operation point. But the total acoustic power could be reduced by 5dB to 10dB, with some tonal reductions up to 13 dB*. The target TRL 4 was fully achieved at large-scale.
The definition, specification, mechanical design and manufacturing of a full-scale demonstrator was done in WP5, ending up at TRL 2-3.
Test activities were closely accompanied by high-fidelity numerical work of WP2.
Overall, InnoSTAT was successful by achieving all of its set objectives.
*É.Salze et al., “Noise reduction of aero-engines using innovative stators with leading edge features”, AIAA/CEAS Aeroacoustics Conference, 4-7 June 2024, Rome, Italy.
Activities on low-noise OGV are ongoing since more than a decade. The selection of 5 different concepts, ranging from passive and active to adaptive, and developing them systematically from small-scale, over large-scale into the final result: a full-scale demonstration for engine integration, is a process which went beyond the state-of-the-art. Using experimental data, 3 OGV concepts from InnoSTAT participants were selected, 2 of them were manufactured on large-scale. Tests with rotating large-scale fan started before end of 2023 and were accomplished short after the project’s end. A full-scale demonstrator was designed and manufactured, based on all results. InnoSTAT followed a scientific process to develop low-noise concepts for the specific noise source of the fan-stator-interaction at a turbofan engine, for the first time from small-scale to full-scale demonstration.
The main impact from InnoSTAT will be generated by the actions planned within the project. They will demonstrate - in a well quantified step-by-step process - the potential of establishing a technology for aircrafts’ noise reduction by providing concepts on demonstrator level, and setting the focus on novel aircraft propulsion systems, such as UHBR, that can make a significant contribution towards:
• Reduction of perceived noise by 65% in 2050 (baseline year 2000) and thus reducing the impact of Europe's air transport operations on the environment. Since aviation has a direct impact on the environment and over EU citizens’ health due to its emissions and noise to which the population is exposed.
Overall, InnoSTAT’s contribution to the abovementioned impact will – due to the nature of the project’s topic – mainly be reasonable in the targeted reduction of perceived noise: InnoSTAT allowed reaching a TRL3/4 aeroacoustics vision of the low-noise slits concept and serrated leading-edge technology, thanks to WP4 Phare UHBR large-scale test demonstrations and achievements. Both concepts - slits and serrations - demonstrated a significant noise reduction level on each of the 3 different acoustic certification points (as confirmed by the TM, see below).
The serrated GEN2 OGV concepts showed a broadband noise reduction up to ~2.5 PWL(dB) and ~6 PWL(dB) respectively on forward and aft fan broadband noise, and up to ~1.5 PWL(dB) on forward and ~4 PWL(dB) on aft for the slits GEN1 OGV concept.
Based on the Phare test rig noise measurements, the TM has performed in-flight noise transposition that leads to high EPNdB noise reduction at aircraft level. After applying a ponderation for uncertainties and further design adaptation to achieve full scale integration feasibility, a potential acoustic benefit of at least 2.5 EPNdB (and potentially even more) is today projected thanks to InnoSTAT’s work (TRL3/4 vision).
The main impact from InnoSTAT will be generated by the actions planned within the project. They will demonstrate - in a well quantified step-by-step process - the potential of establishing a technology for aircrafts’ noise reduction by providing concepts on demonstrator level, and setting the focus on novel aircraft propulsion systems, such as UHBR, that can make a significant contribution towards:
• Reduction of perceived noise by 65% in 2050 (baseline year 2000) and thus reducing the impact of Europe's air transport operations on the environment. Since aviation has a direct impact on the environment and over EU citizens’ health due to its emissions and noise to which the population is exposed.
Overall, InnoSTAT’s contribution to the abovementioned impact will – due to the nature of the project’s topic – mainly be reasonable in the targeted reduction of perceived noise: InnoSTAT allowed reaching a TRL3/4 aeroacoustics vision of the low-noise slits concept and serrated leading-edge technology, thanks to WP4 Phare UHBR large-scale test demonstrations and achievements. Both concepts - slits and serrations - demonstrated a significant noise reduction level on each of the 3 different acoustic certification points (as confirmed by the TM, see below).
The serrated GEN2 OGV concepts showed a broadband noise reduction up to ~2.5 PWL(dB) and ~6 PWL(dB) respectively on forward and aft fan broadband noise, and up to ~1.5 PWL(dB) on forward and ~4 PWL(dB) on aft for the slits GEN1 OGV concept.
Based on the Phare test rig noise measurements, the TM has performed in-flight noise transposition that leads to high EPNdB noise reduction at aircraft level. After applying a ponderation for uncertainties and further design adaptation to achieve full scale integration feasibility, a potential acoustic benefit of at least 2.5 EPNdB (and potentially even more) is today projected thanks to InnoSTAT’s work (TRL3/4 vision).