Wind Power B/C

[Alex-RCHS]

Should I make my turbines concave or convex? Also, should I use tape or glue to attach the turbines to the CD?

Concave, pitch the blade so that it is in the direction of lifting off of the cd. If it were convex, then the turbine cannot catch the wind from the fan.

By this do you mean concave to the oncoming wind?

[kenniky]

I know that scores tend to change based on the fans used, but does anyone have a base line estimate of what i should aim for in terms of scoring?

There's literally no way to measure. Fans are different, motors are different, resistance is different, wiring can be different... heck, even the air can be different.

Literally the best thing you can do is keep on making designs and improving,

[ashmmohan]

Should I make my turbines concave or convex? Also, should I use tape or glue to attach the turbines to the CD?

Concave, pitch the blade so that it is in the direction of lifting off of the cd. If it were convex, then the turbine cannot catch the wind from the fan.

By this do you mean concave to the oncoming wind?

Yeah. This is what it should look like (not as extreme). The goal is for the wind from the fan to 'catch the pitch of the blade and start turning it.

[kssciteach]

Is there an expectation for the relative position of the fan? Should the fan be blowing toward the blades; pushing the wind into the assembly or should the fan be behind the the blade and pulling the wind? We had an issue come up at our regionals. It makes a big difference in how the blades need to be designed.

The rules do not seem to specify this parameter.

[maxxxxx]

Is there an expectation for the relative position of the fan? Should the fan be blowing toward the blades; pushing the wind into the assembly or should the fan be behind the the blade and pulling the wind? We had an issue come up at our regionals. It makes a big difference in how the blades need to be designed.

The rules do not seem to specify this parameter.

I'm not entirely sure what you mean by "fan behind the blade and pulling the wind". Do you mean turning the fan around so it is blowing away from the blade assembly? Think about how this would work with a real wind turbine.

If you meant blowing into the back of the blade assembly, then there are issues with the testing stand being in the way, not to mention having to interpret what "behind the plane of the CD" is to determine whether or not any part of the assembly extends behind it.

[Alex-RCHS]

Is there an expectation for the relative position of the fan? Should the fan be blowing toward the blades; pushing the wind into the assembly or should the fan be behind the the blade and pulling the wind? We had an issue come up at our regionals. It makes a big difference in how the blades need to be designed.

The rules do not seem to specify this parameter.

The following is my interpretation of the rules, and my personal experience, but not an actual rule clarification, as soinc.org is the only place for that:

In my experience the fan is positioned so that the air expelled by the fan is directed at the front of the blade assembly.

Hope this helps.

[JonB]

Is there an expectation for the relative position of the fan? Should the fan be blowing toward the blades; pushing the wind into the assembly or should the fan be behind the the blade and pulling the wind? We had an issue come up at our regionals. It makes a big difference in how the blades need to be designed.

The rules do not seem to specify this parameter.

The following is my interpretation of the rules, and my personal experience, but not an actual rule clarification, as soinc.org is the only place for that:

In my experience the fan is positioned so that the air expelled by the fan is directed at the front of the blade assembly.

Hope this helps.

I agree, that is also my experience.

[0ddrenaline]

Here's a PSA to all of you with low-pitch designs. Make sure that the pitch is adjustable. Our blade was designed for an average fan, and we medaled at every competition. Then at regionals their high speed was lower than our low speed, and our blade didn't move. We couldn't change anything because the pitch was fixed. Keep that in mind

[tltang]

Are there any rules against touching the blade during the testing period? Yesterday we went to the state competition, and oddly the proctor told us we could not touch the blade once it had been put on the stand. Because our blade needs manual help to start spinning, it never moved.

I looked at the rules again, and competition rule f. says, "teams are allowed to adjust, modify, start and stop the blade assembly rotation and re-position the blade assembly or support stand during the measurement period.". The only time you can't touch the blade is in rule g. where it says, "the team must not touch or reposition the blade assembly or supporting stand during the measurement period".

So I am confused where and how the proctor came up with "you can't touch the blade once it is on the stand".

Thanks,

Lisa

[tltang]

Are there any rules against touching the blade during the testing period? Yesterday we went to the state competition, and oddly the proctor told us we could not touch the blade once it had been put on the stand. Because our blade needs manual help to start spinning, it never moved.

I looked at the rules again, and competition rule f. says, "teams are allowed to adjust, modify, start and stop the blade assembly rotation and re-position the blade assembly or support stand during the measurement period.". The only time you can't touch the blade is in rule g. where it says, "the team must not touch or reposition the blade assembly or supporting stand during the measurement period".

So I am confused where and how the proctor came up with "you can't touch the blade once it is on the stand".

Thanks,

Lisa

corretion: what I meant was - competition rule f. says, "teams are allowed to adjust, modify, start and stop the blade assembly rotation and re-position the blade assembly or support stand during the testing period.".