Deadline: 26 January 2018
PhD scholarship in Breaking Waves and their Interaction with Offshore Structures
The Section of Fluid Mechanics, Coastal and Maritime Engineering (FVM) in the Department of Mechanical Engineering (DTU Mekanik) at the Technical University of Denmark has an open PhD position on the subject “Breaking waves and their interaction with offshore structures”.
The main research areas of the FVM Section are fluid mechanics, hydrodynamics, and the interaction with structures and seabed. The methods applied include theoretical, numerical, and experimental modelling, and these methods are used for determining the behaviour of flows, including their impact on surrounding structures. Examples of technical applications include the scavenging process in two-stroke diesel engines, estimation of sediment transport, coastal morphology, and determination of wave loads on ships and off shore structures.
Extreme storm wave events can represent a great threat to coastal and offshore structures. Many older platforms in the sea may have been exposed to subsidence, which makes them more exposed to wave impact. Experiences from the North Sea have revealed that breaking waves occur much more frequently than originally anticipated even in relatively deep water. This might result in higher loading, than originally designed for, especially for the upper structure and upper structural elements. The PhD scholarship is part of a collaboration between DTU-MEK and DHRTC through the project “Dynamics of extreme waves and their interaction with offshore structures”.
Responsibilities and tasks
This project will develop a model that will be used to study breaking wave kinematics an interaction with offshore structures. The mixture of air and water will have a lower density than the water below the mixture of air and water and therefore the exchange of momentum with lower laying water will be reduced. This phenomenon has an effect on the entire dynamics in the broken wave and therefore also on the wave kinematics.
Free surface modelling in OpenFOAM is typically based on a two-phase concept, which makes it difficult to distinguish between the air-entrainment that is found from the model and directly from the mixture of the two phases. The formulation of the free surface shall be extended to a single-phase model (the water) with a void region representing the air. In this way, the air-entrainment model rather than the unspecified mixture between the two models govern the air-entrainment.
The developed model will be calibrated against physical experiments of breaking waves and/or against a stationary breaking wave such as the hydraulic jump. The model will be used to analyse breaking wave forces. Further, the results are expected to improve current force models.
- Develop air-entrainment based on a transport /diffusion equation for the concentration of air.
- Extend the formulation of the free surface to a single-phase model (the water)
- Calibrate air-entrainment model against physical model experiments
- Compare numerical model results to experimental results
- Dissemination of results in conference and journal publications
Candidates should have a master’s degree in engineering or a similar degree with an academic level equivalent to the master’s degree in engineering.
Approval and Enrolment
The scholarship for the PhD degree are subject to academic approval, and the candidates will be enrolled in one of the general degree programmes of DTU. For information about the general requirements for enrolment and the general planning of the scholarship studies, please see the DTU PhD Guide.
In the assessment of the candidates, consideration will be given to:
- Solid background in hydrodynamics/fluid mechanics
- Solid knowledge/experience with Computational Fluid Dynamics (CFD)
- Solid background in numerical methods
- Experience with experimental research
- Experience with Matlab/Phython or similar
- Proactive working style
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and an academic freedom tempered by responsibility.
Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed with the relevant union. The period of employment is 3 years.
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Further information may be obtained from Professor Erik Damgaard Christensen, email: firstname.lastname@example.org.
You can read more about the Department of Mechanical Engineering on www.mek.dtu.dk.
Please submit your online application no later than 26 January 2018 (local time). Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link “Apply online”, fill in the online application form, and attach all your materials in English in one PDF file. The file must include:
- A letter motivating the application (cover letter)
- Curriculum vitae
- Grade transcripts and BSc/MSc diploma
- Excel sheet with translation of grades to the Danish grading system (see guidelines and excel spreadsheet here)
Candidates may apply prior to obtaining their master’s degree, but cannot begin before having received it.
All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.
DTU Mechanical Engineering covers the fundamental engineering disciplines within Solid mechanics, Fluid mechanics, Coastal and Maritime Engineering, Energy systems and energy conversion, Materials and Surface Engineering, Manufacturing Engineering, Engineering design and Product development. The department has a scientific staff of about 135 persons, 100 PhD students and a technical/administrative support staff of about 85 persons.
DTU is a technical university providing internationally leading research, education, innovation and scientific advice. Our staff of 5,800 advance science and technology to create innovative solutions that meet the demands of society; and our 11,000 students are being educated to address the technological challenges of the future. DTU is an independent academic university collaborating globally with business, industry, government, and public agencies.
Apply for this job
Apply no later than 26 January 2018
Apply for the job at DTU Mechanical Eng by completing the following form.