Please show a graph of the mean pressure vs. time which you said has 5 steps over 4 seconds.

Please show a graph of the fluctuation from the mean vs. time, which you said has 20,000 steps over 4 seconds.

What is the 7 and the 200 in the equation 7*20,000*200 above?

Please show an image of the blade. 

I'm not suggesting anything until I understand your model.