Issues with Inflation and K-Omega SST
 

Good Morning,

My university group are currently experiencing some issues with the modelling of our Vertical Axis Wind Turbine on ANSYS Fluent.

We are running a transient 2D simulation of 3 Aerofoil blades rotating round a centre point. The simulation is using K-Omega SST with the coupled pressure-velocity method. We have applied an inflation to the blades to better model the near wall interactions and are getting a Y-Plus value of around 1. The simulation is running for 300 time steps and a force plot is generated displaying the torque produced by the system. Using the torque and the wind speed the efficiency of the turbine can be calculated.

The issue we are having is the simulation is producing too high an efficency for the given set up. It should produce a maximum efficiency of around 28% as per previous literature. We are getting a value of around 40% efficiency with our set up but have achieved the 28% efficiency previously when no inflation was applied.

What could be the issue resulting in the blade inflation generating much higher torques and therefore efficiencies of the turbine?

Many Thanks and let me know if I can give any more details on our set up.