Cfd modelling of h-darrieus vertical axis wind turbine

4.4 GENERATION OF MESH 
In a CFD simulation, the second step is to discretize the entire domain that is being investigated. It's 
a crucial component, and it might also be the most difficult. The fluid dynamics governing equations 
are solved by meshing the domain, which is done by splitting it into many cells. A mesh 
independent solution must be achieved in order to produce a valid solution, which means that the 
findings gained do not vary despite mesh refinement. As a result, a mesh independence study has 
been included, which is detailed in a later section. 
In this project, triangular mesh was created, as shown in figure 17: 
Figure 17: The fluid domain's mesh
 
The ring zone containing the airfoils is the zone with the highest density of elements, as can be 
observed. As previously indicated, this is the zone where the fluid characteristics change the most, 
so it is acceptable to use a denser mesh here. 
Figure 18 demonstrates a zoomed picture of the mesh in the ring zone and around the airfoils: 
Figure 18: The Ring Zone’s mesh 

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Figure 18 shows that the margins of the airfoil are really more refined, in order to capture the 
boundary layer effect and the larger velocity and pressure gradients that occur around the airfoil. 
ANSYS Meshing advance sizing methods were used to build a high-quality non-conforming 
unstructured mesh. In the boundary layer of the blades, an inflation tool has been used to construct 
20 levels of quadrangular cells so that the y+ 1 as needed by turbulence models. [77][78] Outside 
the boundary layer, triangular cells were employed with the same growth rate up to the inside and 
outside interface. To reduce non-conformal mesh interpolation errors, triangular cells at the 
interfaces have the same dimensions for the three sub-domains. 
After the meshing is complete, the named selections must be created. To make setting up the 
boundary conditions easier, the different portions of the domain must be designated.
Figure 19: Named selection list at the left side of the figure 

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Figure 20: Named selection list