Wind Power B/C

[robotman]

Discussion for Wind Power B/C.

Resources:
Wind Power Wiki
2009 Thread (run as Physical Science Lab)
2010 Thread (run as Physics Lab)
2011 Thread
Wind Power Test Exchange 2016

[chalker]

Since I posted something in Air Trajectory, might as well give a high level overview of changes for Wind Power compared to the rules from several years ago. As always, you need to read the actual rules though to understand all the details:

-Used language similar to the robot events regarding commercial kits / designs requiring functional modifications
-Reduced testing time to 3 minutes total per station
-Students indicate to supervisor when to start the voltage measurement period (with fan already on and blade spinning)
-Max voltage during testing period used for scoring
-Written test topics revised to 5 general areas
-Penalty for stopping turning is now only a 0.8 multiplication factor

[joiemoie]

If this is using max voltage rather than max power, this will definitely be a big game changer. Once again, the focus will be on speed then.

[retired1]

Yes and no. it is (max voltage in the 30 seconds measured) squared and that value divided by the load which is to be between5 and 7.5 ohms. Which is in parallel. Seems to me that it should be series.
There is one run at low wind and one at high wind.
The sum of the high wind value plus the low wind value is divided by the highest overall value which means that it is less than 1.0 for everyone but the best score. This is multiplied by 50
Then there is 50 points from the test to be added. So, the best score will be a bit under 100 points. High score wins.
It is true, that the faster you can get it to rotate, thee higher the voltage will be

[chalker]

If this is using max voltage rather than max power, this will definitely be a big game changer. Once again, the focus will be on speed then.

Not really. There is still a resistor in the circuit, and keep in mind the P=V*V/R, thus max power should pretty much occur at the same relative level as max voltage.

[JonB]

In the rules this year (3B) it states that teams cannot modify the CD. Last time this event ran teams could trim down the CD so just the center of the CD is left to attach to the motor and the blades. Does it have to be a FULL, unmodified CD this year? Seems strange to me.

[retired1]

Struck me as a bit unusual, but it does tend to make the teams a bit more even since the wind can not blow thru the CD. We cut it out last time also. Ours looked like an old fashioned windmill.
Oh well, another obstacle to overcome.

[JonB]

Struck me as a bit unusual, but it does tend to make the teams a bit more even since the wind can not blow thru the CD. We cut it out last time also. Ours looked like an old fashioned windmill.
Oh well, another obstacle to overcome.

A rather strange obstacle, in my opinion. I think most teams (well, basically all of them) cut down the CD last time. If I remember correctly, the rules last time specifically stated that it could be cut down, but I could be wrong. But hey, something new and different if we are reading the rules correctly.

[chalker]

Yes, that is a change from previous years. It's primarily a safety issue. We had reports / concerns about teams shattering cd's and the resulting shards of plastic causing cuts and such.

[CTMSRoadScholarKING]

So, I was making the Wind Power tutorial thing on soinc.org under the Wind Power section by KidWind, and the PVC in the nacelle says it is supposed to be 3" long, but it won't make a solid piece like it says. So, would it be a typo so that it isn't a 3" piece or did I do something wrong? Thanks for your help and sorry for the long sentence.