Abstract
In a tidal turbine array, the turbine performance is significantly influenced by upstream wakes. While extensively studied, most research has focused on conventional turbines, leaving a gap in the study of ducted turbines. This paper investigates the hydrodynamic characteristics of a ducted turbine in an infinitely large array. A three-dimensional numerical model of two ducted tidal turbines is constructed using the computational fluid dynamics (CFD) method, followed by experiments in Zhejiang University's circulating flume. The turbine speed is controlled by adjusting the turbine power using resistance boxes, and the experimental results are used to validate the CFD model. Periodic boundary conditions are then applied to simulate an infinite array of ducted turbines. The research proposes a method for predicting the worst-case performance of ducted turbines. In an infinitely large array, as the streamwise turbine spacing increases, hydrodynamic performance gradually recovers. When the spacing exceeds 30D, performance can reach at least 90% of the ideal standalone state. The results summarize the distribution pattern of turbine load fluctuations within an array, showing that the first-row turbine experiences the smallest load fluctuation, while the second-row turbine faces the largest unsteady load, decreasing with each subsequent row.