Furling Input file Yaw2Shft sign convention

Wind & Water Furling
1

Hi, I am simulating an upwind turbine where looking downwind left is the positive y axis. So, does the variable Yaw2Shft in furling input file will stay positive or I have to enter it as a negative value? I am confused about the sign convention.

2

Dear Ruchit,

Figure 18 from the old FAST User’s Guide (drive.google.com/file/d/1d_-vRR … sp=sharing) shows a picture of an upwind furling wind turbine. When looking downwind, if the shaft is to the left of the yaw axis, Yaw2Shft is positive, if the shaft is the right of the yaw axis (as in Figure 18), Yaw2Shft is negative.

Best regards,

3

Hi,

Yes, I provided the input accordingly. But when I reduces the offset (Yaw2Shft) keeping all other parameters same, then the loads and moments (at blade root, LSS shaft, yaw bearing) increases considerably which is quite opposite to that of expected. That’s the reason, I want to be sure about the convention. With consideration to that, does it make sense to have more loads and moment with the reduction in the offset value (I changed value from -0.12 to -0.07)?

Thanks,
Ruchit.

4

Dear Ruchit,

It is difficult for me to comment generally. I would guess that the response would depend on many factors, e.g., reducing Yaw2Shft could reduce the yaw/furl motion, resulting in very different loads relative to the original case.

Best regards,

5

Hi,

I am new to working with the wind technology and FAST. I want to understand what effect would be there on the Design loads at blade root, rotor shaft and yaw bearing by reducing the Yaw2Shft offset, where Tail furl in True and Rotor Furl is False. If I can get some small description for the expected result with this change, then it would be helpful.

Thank You.
Ruchit Shah.

6

Dear Ruchit,

I don’t have enough experience with the design of furling wind turbines to comment. Perhaps someone else on this forum can. It is probably worth having a discussion with a designer of furling wind turbines. e.g., discussing with a design engineer at Bergey Windpower Co. could be ideal.

Best regards,

7

Hi,

Yes, if anyone from this forum can explain a bit about setting up the FAST for furling wind turbine, and how different parameters can affect the result, then it would be a great discussion.

Regards,
Ruchit.