PhD position: Urban sound modelling for innovative air mobility perception studies

PhD position: Urban sound modelling for innovative air mobility perception studies

Join a cutting-edge PhD in aircraft noise modelling and help shape the future of quiet, sustainable flight!

Background

New aerospace concepts like Urban Air Mobility (UAM) introduce air taxi’s and delivery drones in cities that are densely populated. The human impact of these new noise sources, influenced by complex building structures and in the presence of other noise sources, is limited, and scientific studies to understand the impact on people is therefore needed.

The lack in knowledge is related to the models that should be used to auralize UAM in urban environment: new models are needed to predict noise exposure in urban cities. Traditional aircraft noise studies are focused to areas with high noise exposure: areas near the runway or final approach or early departure routes. Current noise models only consider a free propagation path from the sound source towards the observer, and have limitations in including urban influences on the sound propagation. In urban environments, complex urban structures generate an acoustical environment that requires sophisticated noise modelling between the source and the observer. In urban environments, local differences may amplify or reduce noise effects compared to traditional noise models for aircrafts. Human perception in the urban environment is also influenced by other simultaneous (background) sources of sound, which may influence the required accuracy of the propagation model.

An improved model will help finding the perceptual impact of UAM noise in cities, and help to find solutions to reduce noise impact, either at the source, by optimizing aircraft design or adjust operating conditions or routing, or in the urban environment itself by the use of materials, orientation and type of buildings, or the influence of vegetation.

Project description

The candidate will focus on the urban environment and develop a model to predict the frequency dependent noise levels due to Urban Air Mobility vehicles in these areas. These models will not only provide intensity of sound, but also the frequency spectrum and influence of phase differences, as to mimic the perception in real urban environments as close as possible. This will result in monaural sound levels for noise impact assessment and binaural time signals for being used in VR technology as NLR’s Virtual Community Noise Simulator (VCNS). The resulting model can therefore both be used for both perception studies or evaluations to better understand how aircraft noise propagates within a city.

A validation study of this model is key in the development and consists of objective and subjective comparisons. For this purpose, a measurement campaign in a suitable urban area will take place, or at a specific controlled test-site such as NLR’s (MITC) “DigiCity” urban city mock-up initiative, or a similar initiative near Schiphol Airport. As for the subjective comparison, VR experiences based on predicted and measured noise will be compared. Changes at the source are not part of this study, but including realistic sound produced by UAM vehicles is part of this work. Finally, based on these findings, some practical use cases will be worked out to improve perception studies (e.g. using the VCNS) and to demonstrate how noise mitigation measures could be developed in urban environments.

Your profile

• Master’s degree in (Building) Acoustics, Physics, Aerospace engineering or an equivalent study;
• Collaborative and self-directed, and receptive to constructive feedback;
• Good communication skills for spoken and written English. Knowledge of Dutch is desirable but not mandatory;
• Strong background in programming, using MATLAB and/or Python or other relevant programming languages;
• Ability to learn independently and passion for research.

What do we offer you?

You will be employed by NLR as a PhD candidate at NLR Amsterdam. NLR offers you a 4-year research contract, as well as the opportunity to build a professional network in aerospace. As a PhD candidate, you will be enrolled in the Graduate School of Eindhoven University of Technology (TU/e), providing an inspiring research environment, i.e. an excellent team of supervisors and academic staff.

In addition to all this, we offer:

• No fewer than 45 days off (with full-time employment) so that you can also fully enjoy your free time in addition to your challenging job;
• A fixed end-of-year bonus of 8%;
• A contribution towards your healthcare costs;
• Extra paid parental leave;
• The possibility to work from home.

Working at NLR

Royal NLR has been a knowledge organization with the will and ambition to innovate for over 100 years. Based on that motivation, we make the world of aviation and space travel safer, more sustainable, more efficient and effective and stand for groundbreaking innovations. We employ more than 990 passionate professionals, from aircraft engineers to psychologists and from mathematicians to application experts.

A positive VOG screening is necessary for this position.