Experimental and numerical investigations of actuator disks for wind turbines. Issue 7 (10th March 2020) - Ranjbar, Mohammad Hassan
Abstract: The expenses of a wind turbine modeling in particular a wind farm modeling either numerically or experimentally cause to take the advantages of actuator disks (AD). Porous disks (PD) are used to simulate actuator disks in experiments especially for wake studies. A rotor of a wind turbine replaced by a PD can be modeled efficiently with less cost and process time. For a proper PD selection, some semi‐empirical equations are suggested for a range of solidity of 0.2‐0.6. These equations came from a number of tests. The PDs with different dimensions and solidity values were considered for the tests and models. The results of 2D and 3D numerical simulations and the experimental results show that at the solidity of 0.5, the coefficient of performance of a PD reaches approximately 16/27 which is equal to the Betz's limit; the relation between the coefficient of power and the solidity is fitted by a parabolic equation. The average error of the proposed equations for the power coefficient is reported 1.59%. Finally, based on the current results, some semi‐empirical equations are suggested to help the initial PD selection, and then, the cost of further studies may decrease. Abstract : Some equations were extracted to find suitable porous disk geometry instead of using the wind turbine. Both 2D and 3D studies were done and showed that the proposed approach can be used for 3D studies. Proposed approach results in the more cost‐effective study of wind turbines and wind farms using either numerical or experimental approaches.