Job description

Motivation:

Foundation piles for offshore wind become larger (XXL piles), and installation technologies develop further to drive those piles at target penetration depths. These piles radiate noise at low frequencies, usually below 150Hz, for which a more accurate soil description is required (and soil-structure-fluid interaction) since the majority of the energy (>90%) is inserted into the soil and a significant part can channel back into the seawater. Moreover, current numerical models are slow and do not allow for large number of simulations which are usually required for design purposes. At the same time, vibratory installation technologies are under development in order to reduce the noise at-the-source. To date, no validated model exists to predict the noise radiation and seabed vibrations from vibratory installations offshore. This PhD work aims to develop a semi-analytical model for underwater noise emissions applicable to XXL piles for vibratory and impact piling installations. The predictions of the mathematical model will be verified against lab-scale experiments and full-scale datasets. The proposed models also aim to provide a statistical determination of the possible uncertainty due to the variation or lack of accurate dynamic soil parameters. The model will be amended with noise mitigation elements at-the-path to the receiver, to assess the noise mitigation performance of various systems, i.e. air-bubble curtains, HSD systems, etc., and to optimise the overall mitigation strategy. The outputs of this model , including the particle motion and vibrations, shall provide input to the bio-acousticians and policymakers to assess the noise impact on the fish, mammals and invertebrates.

Expected results:

(i) Numerical modelling results of acoustic sound generation and wave propagation in shallow waters using semi-analytical approaches and calibration with actual data during the XXL pile installation and vibratory piling;

(ii) Analysis of the interaction between waves and the variable geometry/acoustic properties of the marine environment by means of parametric studies to evaluate the acoustic transmission paths through seawater and seabed;

(iii) Probabilistic analysis and risk assessment concerning target noise levels defined by noise regulations with and without air-bubble curtains;

(iv) Examination of noise mitigation efficiency at target low frequencies related to XXL foundation piles and proposals for noise reduction strategies by identifying the optimum locations to position the mitigation system to block the tunnelled energy through an elastic sediment;

(v) Conversion of model outputs into the relevant sound metrics to interpret the sound impact on the marine animals.

 

Requirements

The candidate should:

• Hold a M.Sc. diploma in related Engineering field and/or Applied Sciences and/or Physics, preferably in some relation to structural dynamics and/or offshore engineering and/or soil-structure interaction;
• Have an excellent knowledge of the English language;
• Be eager to expand his knowledge in dynamics of structures, soil-structure and fluid-structure interaction and acoustics.

Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the Graduate Schools Admission Requirements.

In case you are a DN-EU grant, please read the following document carefully. (insert link pdf document)

and/or

Mobility Rule: researchers must not have resided or carried out their main activity (work, studies, etc.) in the country of the recruiting beneficiary for more than 12 months in the 36 months immediately before their date of recruitment. Compulsory national service, short stays such as holidays, and time spent as part of a procedure for obtaining refugee status under the Geneva Convention are not taken into account. For international European research organisations, international organisations, or entities
created under Union law, recruited researchers must not have spent more than 12
months in the 36 months immediately before their date of recruitment in the same
appointing organisation. Note that the mobility rule applies to the (first) beneficiary where the researcher is recruited. In case of multiple recruitments, the mobility rule only applies to the first recruitment.

Conditions of employment

Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1,5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2,5 years assuming everything goes well and performance requirements are met.

Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from € 2770 per month in the first year to € 3539 in the fourth year. As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills.

The TU Delft offers a customisable compensation package, discounts on health insurance and sport memberships, and a monthly work costs contribution. Flexible work schedules can be arranged.

For international applicants, TU Delft has the Coming to Delft Service. This service provides information for new international employees to help you prepare the relocation and to settle in the Netherlands. The Coming to Delft Service offers a Dual Career Programme for partners and they organise events to expand your (social) network.

TU Delft (Delft University of Technology)

Delft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context.

At TU Delft we embrace diversity as one of our core values and we actively engage to be a university where you feel at home and can flourish. We value different perspectives and qualities. We believe this makes our work more innovative, the TU Delft community more vibrant and the world more just. Together, we imagine, invent and create solutions using technology to have a positive impact on a global scale. That is why we invite you to apply. Your application will receive fair consideration.

Challenge. Change. Impact!

Faculty Civil Engineering & Geosciences

The Faculty of Civil Engineering & Geosciences (CEG) is committed to outstanding international research and education in the field of civil engineering, applied earth sciences, traffic and transport, water technology, and delta technology. Our research feeds into our educational programmes and covers societal challenges such as climate change, energy transition, resource availability, urbanisation and clean water. Our research projects are conducted in close cooperation with a wide range of research institutions. CEG is convinced of the importance of open science and supports its scientists in integrating open science in their research practice. The Faculty of CEG comprises 28 research groups in the following seven departments: Materials Mechanics Management & Design, Engineering Structures, Geoscience and Engineering, Geoscience and Remote Sensing, Transport & Planning, Hydraulic Engineering and Water Management.

Click here to go to the website of the Faculty of Civil Engineering & Geosciences.

Additional information

For information about this vacancy, you can contact Dr. Apostolos Tsouvalas, e-mail: a.tsouvalas@tudelft.nl.

Application procedure

Are you interested in this vacancy? Please apply no later than 31 December 2023 via the application button and upload your motivation and CV.

• You can apply online. We will not process applications sent by email and/or post.
• A pre-Employment screening can be part of the selection procedure.
• Please do not contact us for unsolicited services.