Community Research and Development Information Service - CORDIS


TAVAC Report Summary

Project ID: 717089
Funded under: H2020-EU.

Periodic Reporting for period 1 - TAVAC (Technologies for Active Vibration and Acoustic Comfort)

Reporting period: 2016-09-01 to 2018-02-28

Summary of the context and overall objectives of the project

In aircraft cabin environments, vibrations and noise co-exist which affect the passenger comfort and quality of flight. Vibrations are typically generated by two main sources: (1) the aircraft engines (turbojet or turboprop) rotating at high speeds and transferred via the engine mounts and the fuselage to passenger area; these vibrations typically lay in the range of 100-500Hz. (2) Additional vibrations are caused by the aerodynamic loads on the fuselage which may affect the global modal response of the aircraft and are finally transferred to the passenger area via the fuselage floor. The latter are significantly lower – up to frequencies of 20 Hz. There are two related important challenges faced in new aircraft development. Challenge 1: The comfort of passengers should be continuously improved. Challenge 2: Most importantly, as more powerful and efficient aircraft engines are introduced and new light-weight airframes are adopted the intensity of engine and airframe vibrations is increased while the damping capacity of the fuselage is reduced, hence, the vibration and noise level in the cabin are increased, setting a barrier in the improvement of airframe and engine efficiency. To address both challenges, special noise cancellation techniques should be employed. The project aims to improve existing airframes and engine technology and efficiency, while sustaining the high level of the customer comfort through the introduction of novel integrated active technologies of noise and vibration reduction. This is accommodated in two discrete, but highly related directions: (1) Active vibration isolation and control; and (2) Active noise control. The project aims to technically improve current successful approaches and to adapt them for increased passenger comfort in business jets. The project objectives can be summarized as:
• Obj. 1: Develop an Active Vibration Control System to accommodate engine vibrations using active engine mounts.
• Obj. 2: Develop an Active Noise Cancelation System to reduce noise discomfort in the passenger area.
• Obj. 3: Develop an Active Vibration Control System to attenuate aerodynamic vibrations transferred to passenger area via the fuselage floor.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In WP1, Task 1.1 - “Conceptual Design, Specifications and Installation Constrains”, the proposed system was presented in order to confirm its feasibility and compliance to system requirements in terms of frequencies, amplitudes and installation constrains (Deliverable D.1.1). In Task 1.2 - “Design (actuator, sensors, amplifier, controller)”, the proposed system was elaborated further, in order to confirm its feasibility and compliance to system requirements in terms of frequencies, amplitudes and installation constrains (Deliverable D1.2).

In WP2, Task 2.1, experimental tests were performed with an ANC system (Deliverable D2.1). The main objective with these preliminary experiments was to examine if the classical LMS Active Noise Control (ANC) system is suitable for reducing noise and examine how large the quite zone could be and how big the reduction is in frequencies excited by sin signal with frequency equal to 110 Hz. In Task 2.2, the definite experimental setup was proposed (Deliverable D.2.2).

In WP3, Task 3.1, “Conceptual Design, Specifications and Installation Constrains”, the proposed solution was presented in terms of feasibility and compliance to fulfil the requested system requirements (Deliverable D3.1). In Task 3.2, the objective was to finalize the design of the proposed anti-vibration setup in the PDR, to reduce the resulting vibration on the aircraft tip due to the aerodynamic excitation applied on the horizontal tail, and to quantify the system performance regarding the set targets for vibration reduction, weight and so forth. Based on the initial design proposed during the PDR the proposed anti-vibration setup that requires to be installed in the aircraft cockpit is a Semi-Active Tuned Mass Damper.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

In the active engine and fuselage vibration control the project will provide the following progress beyond the SoA:
• Will utilize solid-state d33 stacked PZT actuators; also low-cost, light-weight piezopolymer dynamic sensors and/or MEMS accelerometers. The proposed solid-state actuators and sensors will drastically improve effectiveness, reduce power amplifier requirements, eliminate the need of signal conditioning, and will drastically reduce the weight of the actuator-sensor system.
• provide a robust design and optimization methodology, relying on FEA numerical tools, which will enable the optimization of the actuator-sensor network based on the modal-attenuation and filtering concept.
• provide an integrated virtual-testing simulation capability which will predict the attenuated dynamic response of the aircraft structure to the fuselage-floor, coupled with the actuator, sensor and controller systems.

For the active noise control system the first direction for progress beyond the state of the art consists in the design of EAP based loudspeakers for ANC. They can offer numerous advantages over other loudspeaker technologies, such as:

• Lightweight design
• High energy efficiency
• High frequency band selectivity by natural frequency tuning
• High directivity
• Easy embedding in 3D infrastructure through 3D printing
• Tangible feedback for head tracking

The local ANC control at a headrest will offer the following innovative features:
• Efficient sub band adaptive filtering algorithm (SAF) for the optimum combination of narrow-band and broadband ANC.
• Efficient cross-talk cancellation through 3D binaural audio approaches (head tracking possibility of the EAP design, BACCH algorithm)

The developed Active Vibration & anti-Noise Control Systems will become available to industry, SMEs and research community through strategic partnerships and marketing plan. Research results will be disseminated to technology stakeholders (CleanSky partners, industry, research organizations and academia) to enhance composite structure impact knowledge and improve the passenger comfort in business jets. The project is expected to have a major effect on the development of applied technologies for enhanced aircraft performance, a key priority of the CleanSky program and the EU Flightpath 2050 Vision for Aviation. The proposed AVNC concept is very promising because it will enhance passenger comfort, the quality of air-travel and provided services and will offer a competitive advantage for the new regional aircraft.
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top