I noticed, by chance, that if I had an even number of grid points in the turbulence box, then the turbulence intensity calculated at the hub (Vhub stddev/ Vhub mean) would be much smaller than what I would specify in turbsim.in. (both in *outb and in *.wnd)
I tested the same case with odd number of points in the domain to find the turbulence intensity to be correct at the hub. I assume because in this case there is a grid point exactly at the hub.
I played around with the spatial coherence parameters but that only seems to change the turbulence spectrum, not really the turbulence intensity.
- I would like to know if there is any spatial averaging done in the inflow turbulence. I did not find any info in the user guide. Any kind of spatial averaging will result in some degree of destruction of the signal and a reduction in the TI because no two neighboring points are 100% coherent, right? How doe you address this issue?
- If the blade elements are smaller than the distance between two grid points, what inflow turbulence does an element located between two points experience?
- If I use very few grid points in the domain, would there be a significant impact on the loads? Especially the fatigue loads?
All three questions may have just one answer in the end!
Thanks and best regards.