PhD position on “Identification and reduction of sources of sound in positive displacement machines”
Supervisors: Dr Juan Guzman-Inigo, Dr Thibaud Plantegenet and Prof. Ahmed Kovacevic.
Background: Positive displacement compressors/expanders are used in many applications where quiet operation is required. These include compressors used for heat pumps in home applications, installed in passenger transport vehicles or used to supply pressurised air in various mobile machines operating in streets and residential areas. There are several approaches to reduce the noise emissions of these machines, including the use of silencers in the discharge pipes or sound insulators. However, the most effective approach is the reduction of noise at source.
For positive displacement machines (PDMs), two main sources of noise (or sound) have been identified: (i) mechanical sources, produced by the vibration and/or periodic contact of moving parts, and (ii) fluid sources, generated by gas pulsations in the suction and discharge chambers. These two mechanisms produce vibrations of the machine housing and frame that propagate in the air or through the pipes leading to the noise perceived. Although extensive research has been done on the subject, it is still not clear how to design PDMs to minimise all these sources of sound.
In this project, we will perform a systematic study of sound in PDMs using a combination of state-of-the-art experimental, numerical, and analytical tools. The study will include, for the first time, both mechanical and fluid sources coupled with the vibrations of the machine housing and frame.
Objectives: The aim of the proposed research project is to create design tools for the development of quieter positive displacement machines. The project will involve a series of research modules to realise the above aim:
- Review available literature on noise produced by PDMs.
- Develop analytical and numerical tools to evaluate and predict the noise produced by PDMs.
- Create an experimental database to benchmark new predictive tools.
- Identify the main factors which influence noise in PDMs.
Outcomes: The project will deliver the following outputs:
- Comprehensive review of noise produced by PDMs.
- Dedicated noise prediction tool for PDMs.
- Guidelines for the design of “quiet” machines.
The project will fully fund 3 years of a PhD study, including a scholarship and bursary in the amount of £19,450 p.a.
It is expected that the candidate has a good mathematical background, excellent knowledge of thermodynamics, fluid mechanics and vibrations and holds a Master’s degree in mechanical engineering or related discipline. Good skills in using programming languages such as Python or similar are desired. The candidate is expected to have a positive attitude toward teamwork, ability to work proactively and independently and is motivated to learn and contribute to this multidisciplinary project.
For any queries about the post please contact firstname.lastname@example.org
Applications, consisting of a CV and a Personal Statement, should be sent by email to email@example.com
Closing date for applications: 17:00 on 11th May 2023.