Intelligent Structures for Low Noise Environments

Lead Research Organisation: University of Southampton
Department Name: Sch of Engineering

Abstract

Increasing international trade is leading to an explosion in the amount of shipping worldwide, which in turn is increasing the levels of noise pollution in our oceans. This is exacerbated by the large scale of the vessels used with low frequency acoustic radiation from vibrating structures propagating over long distances. The elevated noise and its detrimental impact on sea-life is a significant environmental concern. The power needed to propel such large container vessels is also leading to significant internal habitability issues with associated health and safety concerns. More generally, dwindling natural fuel reserves together with concern over greenhouse gas emissions is leading to a proliferation of offshore and land-based renewable energy generating installations. Such projects are all contributing to increasing noise pollution that in many cases radiates as infrasound (i.e. at frequencies below the threshold of human hearing) that causes unique physiological effects and discomfort in humans. In the automotive sector, similar environmental pressures are leading to lighter material construction and the increasing use of electric power. These trends lead to similar challenges for sound control and in the case of electric vehicles, this involves consideration of the unique psychological effects that cause annoyance that are not present or masked in vehicles powered by internal combustion engines.

The primary vision of the work proposed here is to address the low frequency noise mitigation requirement with an ambitious programme of research aimed at the development of a range of energy efficient novel intelligent structures through the holistic combination of tools and techniques from the key distinct disciplines of active and semi-active control, fluid structure interaction, acoustic modeling, signal processing and numerical optimization and additive layer manufacture. An Intelligent Structure is defined here as a structure that integrates structural elements that encompass novel sensors, actuation including morphing materials, energy scavenging and energy storage, printed electronics, data storage, computing and communications; not only as discrete embedded devices but also printed using advanced additive manufacturing techniques. In combination the components deliver behavior and performance that satisfy multiple objectives that could include energy efficiency, fault tolerance, low noise, low vibration and light weight.

The proposed partnership will be led by the Noise and Vibration Engineering Department of BAE Systems Maritime and the Institute of Sound and Vibration Research at the University of Southampton (UoS) which brings together a well-established and world leading grouping of expertise in maritime noise and vibration mitigation technologies. Working together with Lloyd's Register (LR), UoS leading expertise in fluid structure interaction and electromechanical design and the world renowned EPSRC Centre for Additive Manufacturing at the University of Nottingham this represents a formidable partnership that will deliver intelligent, energy efficient low noise structures and machines to improve the environment and enhance security and safety across a wide domain of applications.

Planned Impact

The Impact Summary should cover potential economic and societal impacts. The questions you should address here are: Who might benefit from this research and how?

In today's society, noise is all pervasive and problematic in working and domestic settings, where it has significant detrimental environmental, safety and health impacts. The control of noise is, therefore, of a high importance due to its impact on both humans and the environment more broadly. For example, the World Health Organisation indicates that noise can lead to effects such as sleep disturbance, cardiovascular disease, reduced performance at work or school and hearing impairment [1], and a recent study estimates that around 1 million healthy life-years are lost each year from traffic noise alone [2]. In the maritime environment, industrial noise due to shipping and offshore industries not only has an impact on humans, but also on marine life that rely on sound for communication, orientation, and locating prey [3]. The development of Intelligent Structures for Low Noise Environments, therefore, has the potential to have a significant impact in a broad range of areas.

Reducing noise, or more importantly, reducing the impacts of noise on humans and the environment, will have a positive impact on both the population's health and the environment. Although a variety of advanced noise control treatments are available, they do not generally offer the adaptability or the multifunctional capabilities of the intelligent structures that will be developed within this programme. In particular, the optimised structures incorporating active elements will enable adaptation to the environmental and human requirements. For example, structures that reduce the subjective impact of the noise rather than simply the sound pressure level will have a positive impact on human's through application in marine working environments, aerospace and automotive applications.

In addition to the benefits on human health of reducing environmental noise, the developed low noise technologies will also provide a lightweight solution compared to traditional high performance noise and vibration control treatments. This will provide a performance advantage in the maritime, aerospace, and automotive sectors, where there is an increasing requirement to use lightweight materials to reduce the carbon footprint through increased fuel efficiency. For example, a 7% increase in fuel efficiency has been predicted for every 10% reduction in a car's weight [4]. This increase in fuel efficiency, which may be facilitated by the research into lightweight control solutions in this programme, has the potential to support a reduction in CO2 emissions and, therefore, make a further positive contribution towards both a healthy nation and a resilient nation.

Finally, in addition to the positive impacts on health and resilience, the outputs of the research programme will have significant economic impact through the commercial exploitation of the developed technologies. This large-scale programme, which is founded on strong partnerships between academia and industry, will provide direct routes to exploitation of the world-leading technologies and manufacturing processes. This commercial exploitation will not only contribute to future UK GDP, but will also provide new opportunities for the UK workforce in a technically advanced area and thus support the productive nation prosperity outcome.

[1] http://www.euro.who.int/en/health-topics/environment-and-health/noise/data-and-statistics
[2] http://www.euro.who.int/__data/assets/pdf_file/0008/136466/e94888.pdf?ua=1
[3] Peng, Chao, Xinguo Zhao, and Guangxu Liu. "Noise in the sea and its impacts on marine organisms." International journal of environmental research and public health 12.10 (2015): 12304-12323
[4] Cheah, Lynette, et al. Factor of two: halving the fuel consumption of new US automobiles by 2035. Springer Netherlands, 2008.

Publications

10 25 50
 
Description The overall objective of this programme is to create new low-noise intelligent structures that can be used to reduce anthropogenic noise in a range of sectors. Key findings in the first year are:

1) Geometrical features in engineering structures can be used to dramatically reduce the sound that radiates when they vibrate. Such "acoustic black holes" can be combined with smart active materials to reduce further the noise that is radiated and enable greater structural integrity in the resulting composite structure. The holistic combination of the best active and passive features leads to a significantly lower energy requirement than using solely traditional active noise control approaches.

2) A practical methodology has been developed for reducing the far-field radiated sound power of a vibrating structure using only sensors and actuators embedded within the structure. The significance of this is that the approach can be used for any complex structure and can be calibrated in any environment so enabling its use in full-scale systems across many industrial sectors.

3) As an extension to the finding described in 2 it has also been shown that such embedded structural actuators can be used to reduce the acoustic scattering that occurs at the surface of the structure in response to an incident sound wave. The occurrence of such scattering is, for example, the reason that noise levels within a train are significantly elevated when it travels through a tunnel.
Exploitation Route The finding could be exploited by many industrial sectors. The focus of the research has been on alleviating noise in the maritime sector and so the findings could be exploited to reduce both internal noise for enhanced passenger and crew comfort but also exterior noise to reduce the detrimental effects of shipping noise on marine life. Although centred on the maritime sector the work has very broad application potential and could be used to deal with the attendant noise challenges in the automotive sector resulting from the increasing use of lightweight panels to increase fuel efficiency and extend battery life.
Sectors Aerospace, Defence and Marine,Energy,Environment,Transport

 
Description BAE Systems AGM 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Supporters
Results and Impact The BAE Systems AGM was an opportunity to present my work on acoustic black holes to an audience that included company investors, politicians and industrial partners.
Year(s) Of Engagement Activity 2019
URL https://investors.baesystems.com/agm
 
Description IOA Bulletin 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact This is a magazine published by the Institute of Acoustics, aiming to inspire young people to consider a career in acoustics. I wrote a featured article (Page 28) on my experience studying acoustics at the University of Southampton.
Year(s) Of Engagement Activity 2019
URL https://www.association-of-noise-consultants.co.uk/wp-content/uploads/2014/11/IOA-Acoustics-A-Sound-...
 
Description New Scientist Live 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was part of a team that ran a range of scientific demonstrations as part of New Scientist Live 2019. The event was attended by thousands of people over the 4 days, and I'm estimating that we must have seen over 500 people through our stand over that time.
Year(s) Of Engagement Activity 2019
URL https://www.southampton.ac.uk/islne/news/2019/10/newscientistlive.page?
 
Description New Scientist Live 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A huge public event where people from all backgrounds with an interest in cutting edge science and engineering come for a day of talks and demonstrations. I was one of two PhD students presenting work in association with the BAE Systems. It was a fantastic experience and I thoroughly enjoyed engaging with a diversity of people.
Year(s) Of Engagement Activity 2019
URL https://live.newscientist.com/#/
 
Description SOTSEF 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The University of Southampton's Science & Engineering Day is an annual festival, celebrating the cutting-edge STEM research taking place at the University. I was involved with designing and supervising a number of demonstrations, including

* An Active Vibration Control demonstration, showing a potential earthquake protection system
* A binaural dummy head, used to expain how the human brain interprets the audio it recieves from our ears
* A loudspeaker array for cars, which is capable of playing different music to the driver and front passenger at the same time
Year(s) Of Engagement Activity 2019
URL https://www.southampton.ac.uk/islne/news/2019/03/science-engineering-day.page?