Thesis – Accelerating the development of a closed vertical slot fishway through numerical simulations

Company Description

We have been electrifying industries, powering homes and transforming life through innovation and collaboration for more than 100 years. Empowered by our goal, we are determined to enable fossil free living within one generation. To succeed we, as one of Europe's leading energy companies, must be fossil-free ourselves.

But that’s not enough. That’s why we are looking beyond our own industry, to see where we can really make a difference.

Join us in our journey towards a fossil-free life within one generation.

Want to learn more about what we do? Visit www.vattenfall.com.

Since Vattenfall is a part of the Swedish critical infrastructure, many of our services are security classed. If this position is security classed the final candidates might be subjected to a security vetting process, according to the Swedish legislation.

Job Description

Power Climate Smarter living - that’s our purpose. We are looking for the brightest students to make this happen. Together you will contribute to a fossil free future. You will have a unique position to contribute to our purpose. All we ask from you is to use your Superpowers and share your energy to help us achieve our goal. 

About the thesis

This project will be carried out at Vattenfall R&D. To comply with the European Water Framework Directive, which aims to achieve a “good” ecological status of all rivers, the national ongoing hydropower relicensing process (NAP) in Sweden works towards mitigating the environmental impacts of hydropower production. This, for example, includes the preservation and reinstatement of upstream and downstream river connectivity, necessary for many fish species to complete their life cycles.

Technical fish passes are one solution to facilitate upstream migration for a range of migratory species. One fish pass solution is the vertical slot fishway (VSF), which consists of a series of rectangular pools with cross-walls notched by vertical slots. While VSFs are suitable for many fish species of different swimming capabilities, the generally low slope of the fishways (<12.5%) presents a constraint, requiring large construction areas and causing high costs when installed at high-head dams.

To ease this constraint while maintaining suitable hydraulic conditions for fish passage, the fishway may be re-constructed to a closed system, like a closed culvert, eliminating the free water surface while preserving gravity-based flow. Yet, however, little is known about the hydrodynamics and fish response to closed VSFs.

The following tasks shall be completed as part of the thesis:

• Review of literature on the hydrodynamics in conventional VSF and fish response.
• Experimental investigation of the hydrodynamics in a conventional and closed VSF prototype for a range of flow conditions. The experimental data collected will be used as input data and validation of the numerical model.
• Numerical simulation of the open and closed VSF using OpenFoam, replicating the laboratory-investigated scenarios.
• Hydrodynamic analysis of the numerical results.
• Discussion of the results under consideration of fish passage requirements.

Qualifications

We are looking for a student to join our journey towards a fossil free future. You are soon to be graduated from your academic studies. You also identify yourself with our principles: active, open, positive and safe.

• The applicant has a background in engineering (or similar), and ideally has some experience in computational fluid dynamics (ideally OpenFoam, and ParaView for analysis) and an interest in fish migrations.
• English language is a requirement.

• Please check with your course/module advisor/professor for suitability before applying for this thesis.

Additional Information

• Start of assignment2024-01-17 or by agreement
• Location: Älvkarleby or by agreement

• Application – a combined document with your CV and cover letter, and grades are to be submitted in the application.
• Deadline for application is 2023-11-30.
• Contact person and supervisor at Vattenfall is: Eric Lillberg, eric.lillberg@vattenfall.com, 070-5372994

Diversity & inclusion - in everything we do

At Vattenfall we build on the fact that diverse teams can outperform homogeneous teams. But we can only unleash and leverage the power of diversity, if we make everybody feel included. Read more about our important work on diversity & inclusion https://careers.vattenfall.com/about-us/diversity-and-inclusion/