Abstract
Two popular modelling approaches to represent a tidal stream turbine (TST) are the actuator disk (AD) and blade element momentum (BEM). In this paper a focus is placed on the AD method and the BEM-AD hybrid method where three different approaches are modelled; they are the actuator disk (AD) model, BEM-actuator disk (BEM-AD) model and lastly a modified BEM-AD model. The results are validated against experimental measurements found in literature, with a key focus on comparing the downstream velocity and turbulence intensity. The modified BEM-AD model allows the radial variation in the disk porous parameter instead of an overall averaged. This approach has shown near optimum prediction of downstream wake velocities and turbulence intensities. Mesh convergence studies have been conducted to optimise the computational efficiency for each approached used. The impact of inlet velocity and turbulence velocity is also investigated.