Numerical Simulation of a Multi-Rotor Diffuser Augmented Wind Turbine System by Flux Reconstruction Method

This study aims to numerically evaluate the aerodynamic performance and wake characteristics of multi-rotor diffuser augmented wind turbine (MRDAWT) systems using a computationally efficient approach. An actuator line method (ALM) is integrated with a high-order flux reconstruction (FR) solver, PyFR, enabling accurate simulation of complex wake dynamics with significantly reduced computational cost. The numerical framework is first validated against experimental data for a single diffuser augmented wind turbine (DAWT), demonstrating good agreement in power coefficient predictions. Subsequently, simulations of a 25-rotor MRDAWT system reveal critical findings regarding the effects of rotor positioning. The central rotors experience a substantial enhancement in aerodynamic efficiency, achieving up to 16.21% higher power output due to the blockage effect from surrounding rotors. The wake structure analysis reveals wake interactions and wake deflections resulting from rotational effects. These results confirm the efficiency and accuracy of the proposed model for predicting aerodynamic interactions in a large-scale MRDAWT system, supporting future system design optimization.