I am currently working on my thesis which compasses the design of a vibration reduction device for wind turbines (mainly tower and nacelle). But first I have to simulate the wind load on my model to find the critical vibration case. I got a wind turbine model from my professor, which I can do simulations on in Ansys. After conducting modal, harmonic and random vibration analysis there is still one problem left: the blades in my model don’t rotate. Somewhere on this forum I read that load on the tower structure due to wind shear or turbulence show up as 3P, 6P, 9P etc (for a three bladed wind turbine). Since I do the simulation on a static model, my critical vibration does’t appear at the 3P, 6P etc frequencies. Now my idea is to apply a wind load model which includes the effect of a rotating wind turbine, so I can use it on my static model. But I still don’t really understand how load on the tower structure due to wind shear or turbulence show up as these 3P, 6P etc frequencies. Can someone offer any explanation or literature which I can read on? Any help is greatly appreciated.