Validation of Three-Dimensional Actuator Disc Approach for a Full Size Tidal Turbine - Anas Rahman

Institute for Energy Systems Research Conference 2016 Hosted by the IES Conference Team Tuesday 6th December 2016 Session 1.a: Fluids Speaker: Anas Rahman Title: On the Validation of Three-Dimensional Actuator Disc Approach for a Full Size Tidal Turbine Abstract: This study outlines the methodology in implementing the actuator disc approach via Reynolds-Averaged Navier–Stokes (RANS) momentum source term for a 20-meter diameter turbine. To date, only few studies have examined the execution of the actuator disc approximation for a full size turbine. Small scale models have fewer constraints than large scale models because the range of time-scale and length-scale is narrower. In particular, applying a very dense mesh is possible at small scale but hardly feasible for large scale applications. Thus, detailed parametric analyses to determine the optimum size of the structured grid cells that represent the turbine, as well as the ideal unstructured mesh size upstream and downstream the turbine have been conducted. The model output parameters have been compared with experimental results found from the literature, where the predicted velocity and turbulence intensity shows an excellent agreement with measurement data. The results also demonstrate that the accuracy of the actuator disc is highly influenced by the vertical resolutions, as well as the grid density of the disc enclosure. The methodology followed in this study may hence be used to lay the groundwork for implementation of tidal turbines by the actuator disc method in ocean scale models. Anas Rahman www.eng.ed.ac.uk/about/people/mr-anas-abdul-rahman Institute for Energy Systems: www.eng.ed.ac.uk/research/institutes/ies Edited and uploaded by Joseph Burchell www.eng.ed.ac.uk/about/people/mr-joseph-­­­­­burchell