  This work is dedicated to studying the influence of yaw angle on the wake
characteristics of a 2.5 MW utility-scale wind turbine using large-eddy
simulations with the turbine's blades and nacelle parameterized as actuator
surfaces. Four different yaw angles are simulated, i.e.,
$\gamma=0^{\circ},10^{\circ},20^{\circ},30^{\circ}$ for three different
tip-speed ratios $\lambda = 7,8,9$. Similarities are observed for both
time-averaged velocity fields and the turbulence statistics of turbine wakes.
Specifically, it is found that the temporal average of the wake deflection, the
velocity deficit and the transverse velocity, the Reynolds stresses, and the
wake width defined using the velocity deficit can be properly scaled using the
characteristic length and velocity scales depending on the thrust on the rotor
and yaw angles. The width of the region influenced by the transverse velocity,
the PDF of the instantaneous wake position, and the standard deviation of wake
position and wake width, on the other hand, are scaled well using the rotor
diameter independent of the yaw angles and tip-speed ratios. These results
suggest that the wake of a yawed wind turbine can be decomposed into the
streamwise and transverse components, and the turbine-added turbulence and the
meandering motion of the wake can be decoupled from the wake deflection for the
considered cases.
