Cfd modelling of h-darrieus vertical axis wind turbine

6.1 SUMMARY OF THE WORK 
In this thesis, a 2D simulation of a H- Darrieus Vertical Axis Wind Turbine is done using one of the 
most popular CFD software package, namely, ANSYS. Several simulations were run at different tip 
speed ratios. The moment coefficient was obtained from these simulations. The moment coefficients 
obtained at different time steps were then averaged for up to two revolutions in the steady state of 
the turbine rotation. Then the obtained average power co-efficient is multiplied by the corresponding 
tip speed ratio. And thus power coefficient of the corresponding tip speed ratio was obtained. In this 
way, the results obtained were used to draw a performance curve. One of the main objectives of this 
thesis is the validation of the simulated result. The validation was done with results of a study 
available in the literature. 
Cp vs λ curves can be used in wind turbine design to determine the rotor power for any combination 
of wind and rotor speed. They provide immediate information on the maximum rotor power 
coefficient and optimum tip speed ratio. 
The Cp vs λ curve of the literature was compared with the one obtained from the simulated results. 
Thus validation of the simulation was done which shows the results match considerably. 
Prior to the simulation, two important studies were done. One is mesh (grid) independent study 
another one is the time independent study. Both the studies are very important to get a good result 
from the simulation sand also to obtain results with optimum computational effort with efficiency. 
This efficiency reduces both computational cost and time. 
 
6.2 CONCLUSION 
Lastly, it can be concluded that: 

In this project, the 2D simulation of a H-Darrieus VAWT was done using Computational 
Fluid Dynamics (CFD) simulation software Fluent. 

Cp vs λ curve obtained from the simulation matches considerably with the experimental 
data.

Sliding Mesh model was used which takes into account the vortices generated by the blades 

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passing upwind on the blades downstream unlike over-simplified MRF model. 

Prior to the simulation, mesh independent and time independent study was done not only to 
validate the result but also to reduce the computational effort 

This study can be used for design optimization and performance improvement of wind 
turbine