Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - ARTEM (Aircraft noise Reduction Technologies and related Environmental iMpact)

Teaser

ARTEM is a four-year research project, started in December 2017, and is devoted to the development of novel noise reduction technologies for aircrafts expected to enter service between 2035 and 2050. The need to further reduce the noise emissions of commercial aircraft becomes...

Summary

ARTEM is a four-year research project, started in December 2017, and is devoted to the development of novel noise reduction technologies for aircrafts expected to enter service between 2035 and 2050.
The need to further reduce the noise emissions of commercial aircraft becomes obvious when considering the current state for the citizens living in the communities in airport vicinity. Even with the current amount of air traffic, there is a strong impact of aircraft noise on comfort and well-being (e.g. caused by annoyance, sleep disturbance, etc.) for many citizens. The expected growth in air traffic in future years, resulting from increased mobility for business and leisure travel can only be accommodated in a sustainable manner, if significant reduction of noise emissions are obtained for each new aircraft.
ARTEM was set up in order to help closing the gap between noise reductions obtained by current technologies - as already applied or being matured in large European research projects such as OpenAir and CleanSky - and the long-term goals of ACARE, i.e. obtain a noise reduction of 65% for each aircraft operation in year 2050 compared to the reference year 2000 value.
Therefore, ARTEM develops innovative ideas and concepts for efficient noise reduction, co called “Generation 3” noise reduction technologies, to a technology readiness level of 3 (experimental proof of concept) or 4 (technology validated in lab).
Within the project it is taken into account, that novel aircrafts introduced between 2035 and 2050, are likely to have different configurations, as for instance the blended wing-body which could provide the desired efficiency gain. The noise signature of these configurations will be strongly influenced by the interaction of several aircraft components: airframe, high-lift-system, propulsive jet of the engine(s), landing gear, etc. The detailed understanding of those interactions is one focus of ARTEM and basis for further noise reduction. Secondly, ARTEM addresses innovative concepts for the efficient damping of noise by dissipative surface materials and liners. The development work focuses on novel concepts not considered so far. The noise reduction technologies will be coupled to the modelling of the anticipated future aircraft configurations assessing the impact in several ways including industry tools, airport scenario predictions, and auralizations.
Initiated by EREA, ARTEM brings together the expertise of a large and diverse consortium consisting of 24 partners throughout Europe: national research centers for aviation research, universities, small-and medium-sized enterprises, and major European aircraft industry companies.

Work performed

The first reporting period (month 1-18) started with a comprehensive specification task. This included the final selection of aircraft configurations to be considered and their detailed description. For the 2035 configuration, the tube-and wing NOVA concept of ONERA was chosen. A boundary layer ingesting (BLI) engine placement was selected due to an expected aerodynamic efficiency gain. The first full-scale computation of aerodynamic and aero-acoustic fields of a BLI configuration was achieved. For the 2050 configurations, a detailed configuration analyses has been carried out defining two blended-wing-body aircrafts as possible candidates. BOLT – a Blended wing body with Optimized Low-noise Technologies - is considered the best candidate within skyline 2050 for long range commercial routes (400 pax, 5500nm) using conventional UHBR engines (BPR≥16). REBEL – a REgional Blended-wing-body ELectric-propelled – is considered as disruptive concept with hybrid propulsion system, devoted to medium range commercial routes (100pax, 900nm).
Within WP1, focusing on reduction of noise propagation, several liner concepts have been investigated. A basis for their development is a detailed requirement analysis provided by RRD as one of the leading aero-engine manufactures. First liner samples - including active and passive concepts – have been build and tested. Numerical studies have been performed to simulate expected effects. For comparative testing and assessment of acoustic efficiency of the different liner concepts, two test-rigs have been prepared. Two test campaigns were conducted in the Anechoic Chamber AC-2 of TsAGI to obtain validation data for the prediction of noise shielding effects.
In WP2, the interaction effects are assessed through model-scale experiments, numerical calculation and the development of semi-empirical/analytical models with the final goal of low-noise design solutions.
In the first phase of the project, there has been a benchmark of different numerical tools assessing noise generated by the high-lift system. First wind tunnel test have been performed with different landing gear configurations (model scale) relevant to the novel aircraft configuration. Test setups have been designed and manufactured for the examination of the fundamental physics of trailing edge noise reduction using 3D surface treatments (finlets). Further, the design of a wind-tunnel test setup for the investigation of the interaction of distributed propellers has been achieved (1:3 scale). The three propellers can be mounted in front of the wing (tractor configuration) or above the wing (pusher configuration). It will serve for the aero-acoustic investigation of distributed propulsion and interactions effects of neighboring propellers.

Final results

\"ARTEM supports the maturation of low TRL “Generation 3” technology solutions aimed at 2035 / 2050 noise reduction targets.
As such, it brings together a critical mass of innovative ideas and teams to initiate a new research phase beyond the successful Silence(R), OPENAIR, and Clean Sky programs.

The selected liner concepts are matured to a point, where the comparative testing in a single relevant test setup will reveal the most promising concepts. At the end of ARTEM, those technologies will be also assessed with respect to their applicability to Clean Sky 2 configurations and transferred to other technology development projects for future maturation.

The interaction noise effects considered in ARTEM are of highest relevance for current and future aircraft configuration, as isolated reduction means do often not obtain the expected noise reduction (as obtained in isolated tests) in the full-scale aircraft application due to the negligence of the existing interactions.

Following results are expected at project end:
• Description of effects and associated noise reduction methods by design or other means for interaction noise sources encountered at novel configurations
• Set of liners and associated manufacturing practices at TRL4 capable to improve damping performance beyond current limits (broadband, low-frequency, overall damping)
• Synthesis on further novel absorption concepts at TRL3-4 and assessment of their acoustic performance under flow conditions
• Assessment of the impact of investigated noise reduction technologies for ACARE noise targets
• Feedback from hearing test participants exposed to auralization of novel aircraft configurations

ARTEM is designed to support the European efforts to meet the ACARE2050 goals. It implements the XNoise \"\"Generation 3\"\" noise reduction technologies for 2035/2050.

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Website & more info

More info: http://www.dlr.de/ARTEM.