PhD scholarship in Turbo-Expanders with Two-Phase Expansion for Organic Rankine Cycle Power Systems

Updated: about 2 months ago

DTU, Technical University of Denmark, and Technion, Israel have recently started up an exciting, interdisciplinary collaboration project within the EuroTech alliance. We aim at designing innovative turbo-expanders with two-phase expansion for organic Rankine cycle power systems. The research disciplines involved are thermal sciences, mechanical design, manufacturing engineering and materials science. Numerical as well as experimental work is included. Currently we have an opening for a PhD position at DTU, Department of Mechanical Engineering within this project. Another PhD student related to this project will be hosted by Technion.

The organic Rankine cycle technology has gained worldwide acceptance as an efficient way to utilise low-grade heat sources. It is possible to increase the power output of an organic Rankine cycle unit by expanding a two-phase mixture of the working fluid. Moreover, organic Rankine cycle systems featuring an expander that can operate with a two-phase mixture would easy the control of organic Rankine cycle systems utilizing fluctuating heat sources (e.g. solar heat and combustion engine exhaust gases). However, the primary challenge with two-phase expansion is the design of expanders that can handle two-phase mixtures appropriately.

Responsibilities and tasks
The research work includes the numerical and experimental analysis of turbo-expanders with two-phase expansion for organic Rankine cycle applications. The PhD student at DTU will be responsible for the tasks related to thermal sciences, while The PhD student at Technion will be responsible for the tasks related to solid mechanics and material science. If you have a passion for research and a mechanical engineering background with knowledge about turbomachinery design, thermal sciences and manufacturing engineering, you may be the person we are looking for. You will become part of a leading international research team and together with colleagues; you will get the opportunity to conduct groundbreaking research, ranging from detailed numerical analysis to experimental verification. The results of your research will contribute to expand the use of renewable energy sources and make energy systems for efficient, reducing carbon dioxide emissions and mitigating climate change. You will get the chance to publish your work in top-level scientific journals and at international conferences. It is also likely that your work will result in patents.  

Examples of your responsibilities are the following:

  • Development of a preliminary expander design using mean-line and 3-dimensional aerodynamic design approaches
  • Analysis of two-phase nozzles
  • Digitalization of the manufacturing process by developing models to predict the manufacturing time and cost of turbo-expanders
  • Multi-objective optimization considering the performance, and production and material costs of the expander, enabling to identify the optimal expander design
  • Adaptation of the organic Rankine cycle test rig at DTU
  • Preparing for and advising the manufacturing of the expander prototype
  • Steady-state and dynamic operation testing of the organic Rankine cycle unit at DTU
  • Evaluation of the effects on the performance and erosion of the expander of operation with a two-phase mixture
  • Evaluation of the organic Rankine cycle unit reliability/controllability due to the two-phase expansion

Candidates should have a two-year master's degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master's degree.

Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see the DTU PhD Guide .

We offer
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 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 upon with the relevant union. The period of employment is 3 years.

You can read more about
career paths at DTU here .

Further information
Further information may be obtained from Associate Professor Fredrik Haglind, tel.: +45 4525 4113.

You can read more about Department of Mechanical Engineering at .

Please submit your online application no later than 5 April 2020 (23:59 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 out 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.

Applications and enclosures received after the deadline will not be considered.

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 80 persons.

Technology for people
DTU develops technology for people. With our international elite research and study programmes, we are helping to create a better world and to solve the global challenges formulated in the UN’s 17 Sustainable Development Goals. Hans Christian Ørsted founded DTU in 1829 with a clear vision to develop and create value using science and engineering to benefit society. That vision lives on today. DTU has 11,500 students and 6,000 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. Our main campus is in Kgs. Lyngby north of Copenhagen and we have campuses in Roskilde and Ballerup and in Sisimiut in Greenland. 

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