CFD
MODELLING
ANSYS FLUENT has been used to establish a CFD model, which is a software
used for CFD modeling. In this section, CFD modeling of NREL PHASE VI
wind turbine blades has been performed. The computational domain and
boundary conditions, mesh, turbulence model, solution method and
convergence criteria used in the CFD modeling are presented in this
section
Computational domain of airfoil,
blade and their boundary
conditions
The use of Ansys commercial software performs the construction of the
computational domain and grid generation for S809 airfoil. It is widely
accepted that the use of the C-shaped domain is quite dominated in 2D
airfoil simulations [23-26]. So, the designed C-Shaped Domain, along
with S809 airfoil and boundary conditions, are presented in figure 5.
From the previous work, it has been found that NREL PHASE VI is a
two-blade turbine and it possesses 1800 periodicity
and hence one blade is modeled while performing CFD analysis. However,
in this study author is trying to investigate the performance of the
NREL PHASE VI turbine by considering three blades., Due to the symmetric
nature of a three-blade wind turbine, the domain is made for a single
blade to reduce computational time and by using periodicity, the
solution of flow simulation around one blade gets extrapolated to two
other blades to visualize the complete rotor [27-29]. The domain
follows the 120° radial stream tube design in which the velocity inlet
is kept behind 12 m from the blade and maintained the arc of 12 m
radius. Whereas, the pressure outlet is placed at 24 m from the blade
and the outlet surface maintained the arc of 24 m radius. The top
surface is also considered to be the inlet and exhibit the same
velocity. The computational domain and boundary conditions for the wind
turbine model are depicted in Figure 6.