Active reduction of noise transmitted into and from enclosures through encapsulated structures

Project Information

IN-NOVA

Grant agreement ID: 101073037

DOI

10.3030/101073037

EC signature date 7 July 2022

Start date 1 October 2022

End date 30 September 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 2 522 160,00

Coordinated by

POLITECHNIKA SLASKA
Poland

Periodic Reporting for period 1 - IN-NOVA (Active reduction of noise transmitted into and from enclosures through encapsulated structures)

Reporting period: 2022-10-01 to 2024-09-30

Summary of the context and overall objectives of the project

The European Environment Agency alarms that noise pollution is a major environmental health problem in Europe. More than 125 million people are affected by noise levels greater than 55 dB. In Europe, noise pollution causes 43 000 hospital admissions per year and at least 10 000 cases of premature death per year. People are becoming aware of the negative consequences of prolonged exposure to noise and more often seek to reduce it. Unfortunately, this has not yet been solved, and still requires high efforts.

The main goal of the IN-NOVA project is to develop the noise-reducing methods by training 13 Doctoral Candidates through intersectoral, multidisciplinary and international joint research. Scientific objectives of IN-NOVA project are based on a precisely targeted dual noise problem, related to the transmission of noise into and from enclosures through encapsulated structures that concern a vast majority of the population and this can be divided into the two key objectives:
1. Develop comprehensive noise-reducing casing solutions that globally control the excessive noise generated and radiated by industrial devices and household appliances, whilst consuming much less energy, sensors and actuators than classical Active Noise Control (ANC) systems. This is referred to as the in-out problem.
2. Develop versatile active/passive control techniques for the reduction of noise transmission into enclosures, as represented by vehicle and aircraft cabins. This is referred to as the out-in problem.

The first of the considered techniques is called the active noise-reducing casing method (in-out problem). The idea is to enclose the noise generating device in an additional thin-walled casing or to use the casing of the device, and make its walls vibrate by using small-size piezoelectric or electrodynamic exciters. The control system provides signals to drive the exciters and change the structural properties of the casing in order to acoustically isolate the device inside (effectively block the noise using the casing). When appropriately implemented, this method results in a global reduction of noise.

The second main concept for creating active acoustic barriers has been applied with high performance to vehicle cabins and other small enclosures (out-in problem). The sound field in small spaces can be controlled by using vibration exciters or loudspeakers to generate a secondary field that has a similar amplitude but opposite phase to an unwanted noise field and thus results in noise reduction through destructive interference. Thus, in the vehicle application, this protects the passengers from the noise generated by the engine and the tyre-road interaction.

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

The Project is successfully following the planned objectives. Within the first year of the Project implementation, all 13 Doctoral Candidates (DCs) have been recruited, employed and enrolled to the PhD programs. As of the day of writing the report, 15 out of 39 secondments (38%) have been already completed. All of the DCs successfully advances their research, preparing the basis for the dissertations. Nearly half of them already published or submitted journal papers, while the others published their already obtained results in form of conference papers or other reports. The network-wide events have also been organized according to the plan (so far 7 out of 11 planned network-wide workshops/trainings have been completed). Exactly half of scientific deliverables (5 out of 10) and milestones (4 out of 8) have already been completed – all according to the planned timeline.

One of the two main IN-NOVA objectives is to develop active noise-reducing casings, capable of global reduction of noise of many devices in industry and at home. This is being achieved by making their casings vibrate and block transmission of noise in this way. The work carried out provides new knowledge to enable the development of novel encapsulated noise barriers, including design and implementation of distributed active control systems, advanced sensing and holistic soundscape approach.

The second main objective of IN-NOVA is to develop cabin noise reduction systems, enhancing passenger comfort and enabling overall vehicle/aircraft mass reduction. The investigated methods are based on the out-in noise reduction concept, hence the fundamentals are common with active casing approach, which encourages strong interactions, although the specific “casing” structures, acoustic environments and noise properties are different. The work carried out helps to better understand the current state-of-the-art solutions and develop new methods used for noise mitigation, including advanced modelling and simulations, design of active noise barriers, and acoustic metamaterials.

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)

The demand for a quieter and healthier human environment is growing rapidly and needs experts possessing a comprehensive knowledge and practical experience in noise control technology. Currently, market-available solutions are not sufficient in many cases. Regulatory guidelines also favour demand in the noise control system market. But through the completion of IN-NOVA new feasible and comprehensive noise reducing systems are being developed and delivered, boosting the advancement of European companies in this field and allowing them to take advantage of the growing noise control market, as well as motivating decision makers and politicians to undertake planned actions thanks to organised meetings with them.

The IN-NOVA Project for the first time investigates the reduction of noise passing through encapsulated structures in a complete manner, considering both in-out and out-in forms of this specific, but ubiquitous problem. It is possible thanks to interdisciplinary and complementing composition of the Consortium, integrated into well-coordinated network. Exploration and integration of synergies between the hitherto disjointed noise control techniques creates new knowledge and enable development of two complete systems reducing noise (i) generated by devices and (ii) in cabins.

Two comprehensive and feasible noise control solutions are developed within the project, dedicated to vehicle/aircraft cabins and device casings. Although related and synergetic in many aspect, they are tailored specifically for the two targeted problems, going far beyond the current state of the art. Within the course of the project, at least 30 articles will be published in very prestigious journals in vibroacoustics. At least one monograph will be published by a well-recognized publisher. The realization of IN-NOVA will develop new standards for noise control systems for encapsulated structures, providing an impetus for the research in this field for many years.

A conceptual sketch of technologies developed within IN-NOVA.