The hub must be higher than half of the turbulent wind field height

This error message can occur when you attempt to start a simulation with wind type set to turbulent wind and generating the wind field from parameters.



The size of the turbulent wind field is automatically set to 1.1 of the size of the wind turbine's rotors area and is centered at the rotors' area center (e.g. for a rotor with a diameter of 50 m, a square wind field with height and width of 55 m each would be generated). 
If the hub height is too low compared to the rotor size such that the turbulent wind field would stretch below the ground or the sea surface, this error is prompted (e.g. the rotor diameter is 50 m like written above and the hub is at a height of 22 m, the generated wind field would stretch by 0.5 m below the ground). This is due to restrictions of TurbSim.

1 How to resolve it

This error can be resolved by either choosing blades with a shorter length or by increasing the hub height, e.g. by enlarging the support structure.