Močno vezane računalniške simulacije s tokom gnane Darrieusove turbine : doktorska disertacija

slovenian

doktorska dela

2014

computational fluid dynamics   Darrieus turbine   finite element method   fully coupled simulations   hydrokinetic turbines

Univerza v Mariboru, Fakulteta za strojništvo

Among conventional systems for river energy extraction the new types of turbines are considered in the recent time that can be deployed in a free stream without impounding of a waterway and represent a minor impact on an environment when compared to conventional power stations. Procedures for analysis of these turbines are based on different aerodynamic models, while modern methods based on computational fluid dynamics have been applied only recently. Even those are performed using prescribed operational parameters, such as constant rotational velocity. To acquire the whole operational characteristics more simulations have to be performed. For a deeper understanding of operating principles the new simulation procedure has been developed, which employ flow driven approach, which enables more realistic condition in a simulation. Using such approach it is possible to acquire the whole operational characteristics of a turbine for a certain flow velocity within a single simulation. The blades of such turbines, especially in horizontal axis position, represent long and slender structures that are exposed to hydrodynamic loading during operation. This causes blade deformation, which instantly changes flow conditions around it. The consequence is altered performance of a turbine. Using a combination of flow driven approach and fully coupled fluid structure interaction in a simulation it is possible to assess the influence of blade deformation to the turbine performance. Therefore the routine has been developed to enable simultaneous use of fluid structure interaction and a flow driven approach. To validate the newly developed simulation procedures the experiment with a scaled model of a turbine was performed on a natural waterway. The results of experiment and simulation showed a good agreement. Comparison of simulations based on conventional and newly developed approaches pointed considerable differences in turbine operation. Therefore it is reasonable to use developed simulation procedure as well as its further development.

08.08.2023