Effects of Inflow Parameters and Disk Thickness on an Actuator Disk inside the Neutral Atmospheric Boundary Layer

Abstract

An accurate choice of the inflow parameters has been shown to affect the CFD results significantly. In this study, the actuator disk method (AD) is used to investigate the effects of the widely used inflow formulations, the logarithmic and power-law formulations, in the neutral atmospheric boundary layer simulations. Based on the one-dimensional momentum theory, the AD model is a rapid method that replaces the turbine with a permeable disk and is among the most used methods in the literature. The results of the k-ω AD simulation indicated that in spite of the logarithmic method’s widespread use, the power law formulation gives a better description of the velocity field. Furthermore, an actuator disk thickness study also showed that given the effect of actuator disk thickness on the rate of convergence, more attention should be dedicated towards finding a suitable disk thickness value. The combination of an optimized mesh and a suitable choice of AD thickness can help with the rate of convergence which in turn shortens the simulation’s run time.

Keywords

• wind turbine simulation
• actuator disk
• atmospheric boundary layer
• CFD
• wake recovery