Darrieus Wind Turbine

Simulation Methodologies for the Darrieus Wind Turbine

Authors: Md Mahmud Hasan Saikot, Mahbub Siam, Mahfuzur Rahman, and Dr. Maglub Al Nur

Abstract

The most exploited design choices for the Darrieus turbines are the H-shape configuration, also called straight bladed configuration. Though it has a great performance in high tip speed ratios (TSR), it performs poorly in low TSRs. The simulation results also become unstable in low TSRs due to large angle of attack variation and separation. This leads to inaccurate and often misleading results in low TSR simulations of Darrieus turbine. The rotation and curvature is also a very important consideration in the simulations. In this study, high fidelity unsteady 2D simulations were exploited to analyze a three-bladed H-Darrieus wind turbine in low TSRs to predict a stable and accurate simulation model. The Standard SST and curvature corrected SST models were analyzed in-depth. Mesh and timestep sensitivity were also performed in great details. CFL number and Wall Y+ parameter have been used to observe the performance of our simulations in different TSR ranges. A detailed outline for stable and accurate simulation have been generated.

Fig: Comparison Between Simulations done with two different Turbulence Models.