Thesis project Concrete damages in spillways – CFD studies

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. 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 fossil freedom.

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.

The project is to be performed at Vattenfall R&D.

Thesis background/subject/assignment

A spillway is probably the most critical structure with respect to dam safety. Floods must be discharged without jeoparding the dam structural integrity. This means that the waterway has to withstand the impacts of the flood water. Even a limited extent of deficiency may limit its discharge function. However, damages do occur unexpectedly, even in low-head chute spillways, after regular operations without being exposed to extreme flood events.

It is suspected that cracks may delelop in the chute floors due to e.g. poor construction quality, low concrete strength, changing operation conditions etc. Turbulent flow enters the cracks and even construction joints, generates uplift forces and leads to structural damages (even at small discharges), which is often the cause of damages in spillway structures. Understanding the flow dynamics and pressure propagation beneath the concrete slabs is essential for safey operation, repair and re-design of existing chute spillways.

Thesis goal/purpose

The project aims to achieve the following goals. (1) To map the flow patterns at different operation conditions of a chute spillway and to identify the worst scenario. (2) To clarify the reason for concrete damages. (3) To suggest potential remedial measures or reshape the chute longitudinal profile.

This assignment is for one student or two.

Execution

With an existing dam in the background, the study is executed with the help of CFD modeling with ANSYS FLUENT. The previous model tests is reviewed. Representative flow cases are simulated so as to capture the most unfavorable operation scenario. Potential countermeasures are also examined in the modeling.

For the students

• To get familiar with the ongoing work with dam safety and dam upgrade projects in the country
• To learn about hydraulic model tests
• To learn the fundamental knowledge of CFD
• To develop CFD skills for simulations of spillway flows

The project consists of the following aspects.

1. Background and literature review
2. Data collection
3. Learning of CFD modeling techniques
4. CFD model setup (with experimental verification)
5. CFD simulations and result analyses
6. Report writing

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.

• Education - proper background is university education in civil (hydraulic) engineering, engineering physics or similar disciplines.
• Scope - the project corresponds to a 30 hp diploma work.
• Very good command of written English is required.
• Strong interests in hydropower, dam safety and hydraulic engineering.
• The time of execution should be within four (4) months, completed during 2025.

Additional Information

More information

• Start of assignment – January 2025 or by agreement
• Location – Älvkarleby, Stockholm or by agreement
• Application – a combined document with your CV (with complete contact information) and cover letter, explaining your interest for hydropower. University grades are also to be submitted in the application.
• Deadline – the deadline for application is 2024-12-08. Incoming applications are processed on a running basis and the vacancy is filled as long a suitable candidate is found (the announce is then removed). This is the reason why you should not wait to the deadline to send in your application.
• Contact person and supervisor at Vattenfall – James Yang, james.yang@vattenfall.com, phone 070-2723 200. Inquiry can be made by phone.

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/