Selecting your area to make sure you good results for your turbines and meteorological masts
To ensure that the windfields that WindSim produces are of good quality in the relevant area we are employing a strategy of having a refinement area, of high resolution and a buffer area surrounding it with lower resolution.
The orange box in the figure is the refinement area, while the surrounding black box is the extent of the buffer zone.
Refinement area:
The refinement area the parts of the simulation where we are expecting results to be representative. Using markers this is automatically set to be extend 2 km outside the markers, which can represent the turbines or meteorological masts. Since we want to capture as good as possible the ground effects near the relevant points we want to have the high resolution extended around the turbines as well.
Using the box selector we also recommend to extend the refinement area from the area as well.
Buffer Zone:
The buffer zone is there to minimize the impact of our boundary conditions. At the inlet, where the wind is flowing in, we are assuming that the wind has a logarithmic profile depending on the roughness of the ground. By letting the wind flow over the buffer zone it will develop a more realistic profile when it reaches the refinement area and the boundary effects are reduced.
Here it can be important to make sure that the edges of the buffer zone does not have to many significant features. A large cliff on the edge of the simulation domain, i.e. the buffer zone can cause significant effects which may extend into the refinement area.