Intelligent Structures for Low Noise Environments

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.

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.