2D Actuator Disk and Vertical Axis Rotor Model in the Wave-Current Unsteady Flow

2D Actuator Disk and Vertical Axis Rotor Model in the Wave-Current Unsteady Flow

Shan, Y.

Simao Ferreira, C.J. (mentor)

Applied Sciences

Sustainable Energy Technology

2013-10-22

A cross flow actuator based on a turbine concept is a possible choice for the harvest of the kinetic energy from a dynamic flow. Since there is a large potential of energy contained in the water movement of the ocean, it is fascinating to apply turbines to extract energy. In marine flows, currents can be described as steady since their flow velocities remain unchanged during long periods, while waves are treated as unsteady due to their variation within short periods. In some regions, the flow is a combination of both the current and the wave. Thus, it is interesting to understand how the turbine behaves during the operation in this unsteady flow. The current work tries to model the marine turbines by numerical methods. Two branches are then studied separately. The first model is built within a 2D rotor scale in which the turbine is represented as an actuator disk. Case studies are built with different wave and current velocity scales. The second model studies the case of the Vertical Axis Turbine (VAT) by integrating the wave model with a 2D VAT panel code. The simulation results from the actuator disk model suggest that it is more feasible to extract energy from the case when the current is dominant, while in the other cases, the flow is dominated by the unsteady response with large variations of power or even negative power output observed. The results from the VAT model show that for all the wave current combinations, the turbine can reach a regular periodic performance under the operation condition where the blade rotation period equals the wave period. The further study of the load behavior indicates that the turbine’s response can be controlled by tuning the phase difference between the wave flow and the blade rotation.

Windenergy

http://resolver.tudelft.nl/uuid:9fa21837-34f3-4989-8a4e-10345f59ece3

Student theses

master thesis

(c) 2013 Yuan Shan