Project outline
Aircraft noise remains a major environmental challenge as the aviation industry moves toward quieter and more sustainable propulsion systems. Low-frequency noise, produced by jet engines and fans, is particularly difficult to suppress using conventional acoustic liners due to its long wavelengths and high energy content.
This PhD project will explore the use of acoustic metamaterials to achieve effective low-frequency noise reduction in aircraft systems. Working with world-class academics at the University of Bristol and several industry and academic partners, you will investigate novel liner concepts designed to suppress low-frequency broadband noise. The project aims to develop compact, high-performance acoustic metamaterials that can significantly reduce aircraft noise footprints and support the next generation of quiet, efficient, and environmentally friendly air transport.
Project Partners
This project is based at the University of Bristol.
Further project information
Acoustic liners are specially designed surfaces used in aircraft engines and propulsion systems to absorb sound energy and reduce the noise that reaches the environment. Traditional liners often struggle to control low-frequency noise because the long sound wavelengths are difficult to absorb within the limited space available in modern aircraft structures.
Low-frequency metamaterials represent an emerging frontier in aeroacoustics, offering new possibilities for noise reduction beyond the limits of conventional passive treatments. In contrast to traditional liners, metamaterials can achieve strong acoustic control through subwavelength resonant mechanisms, that enable efficient sound absorption at frequencies previously difficult to reach. By integrating elements such as Helmholtz resonators, membrane absorbers, and labyrinthine channels, these materials can be engineered to exhibit locally resonant behaviour, that allows precise tuning of their acoustic response.
The PhD candidate will conduct experiments using the state-of-the-art Grazing Flow Impedance Tube at the University of Bristol, that enables detailed characterisation of liner performance under realistic flow and acoustic conditions. The work will also make use of advanced measurement tools, including high-speed Particle Image Velocimetry (PIV) and hot-wire anemometry, to capture detailed flow–acoustic interactions.
The project involves close collaboration with industry partners and offers placements with both academic and industrial collaborators, providing a strong platform for research impact and professional development. The student will also be encouraged to participate in international training schools and conferences, presenting their findings to the wider aeroacoustics and metamaterials research community.
Subject Areas
- Acoustic Metamaterial
- Fluid Dynamics
- Experimental Methods
- Aeroacoustics
- Noise Control
- Sustainable Aviation
Required qualifications/skills
Essential
- A minimum of a 2:1 undergraduate degree in Aerospace Engineering, Mechanical Engineering, Civil Engineering, Physics, or a related discipline.
Student
Commencing in October 2026