The classical trash-racks, placed at the entrance of intake channels of hydropower plants, have as main purpose the protection of the turbine from floating debris. The new era of trash-racks or so-called eco-friendly bar-racks, is an emerging technology to protect also the environment, for instance by guiding wandering fish into a safe bypass route.
Research on alternative behavioural guiding systems is currently rather limited, focusing on guiding racks or repulsion systems. However, recent advances in the knowledge on behavioural responses to turbulence eddies point toward the possibility of exploiting the species innate preference and avoidance of eddies of different characteristics to create migration paths passed the intakes. It has been shown that some eddies may boost swimming whereas others can hamper swimming. Turbulence eddies may be crated in new rack designs or alternative structures that efficiently interconnects the desired turbulence eddies into a migration path. Thus, the method requires proper characterization of flows around these elements to address its effect on fish guidance.
The student will work together with researchers and professors from NTNU and SINTEF Energi with both design and processing various solutions of bar elements in numerical environment.
The topic offers an opportunity to deepen the applicant's knowledge in advanced numerical modelling with open access software and to interpret the hydraulic outcome of the study from the perspective of different fish species (e.g.: Atlantic salmon, European eel, Brown trout).
The expected tasks during the semester are the following:
- Familiarize with different bar elements and flow around them in open access CFD software
- Combine the simulated hydrodynamics with known preferences of fish species
Master thesis aims for an analysis of the transition from open channel to pipe flow, based on CFD simulations, using OpenFOAM.
Figure: Transition from open channel to pipe flow