Wind Power B/C

[GoldenKnight1]

4) A blade assembly with violations is still allowed to run (with the 15 point construction violation) because rule 4.c does not specify any consequence if the team does not fix the construction violation(s). This opens up an interesting situation if a team finds a way to increase their voltage score by at least 20% by breaking a construction rule ..... Maybe blade assemblies that don't meet the construction rules and don't / can't be fixed get zero in Part I (rule 5.f)
.

This is why I like to ask for suggestions / comments. The wording in 4.c. is supposed to prevent blades that don't meet specs from being tested, but I can see how it could be read otherwise.

Also what is the overall difference in score between a team that (a) has no blade, (b) has a blade with a construction violation that they correct, and (c) has a blade with a construction violation that they never correct? I would argue that without knowing specifics that I think B is the best of these, followed by C, and A being the worst.

[lazyguy01]

I would like to second the change to using voltage rather than power (v^2/r) for the Part I score.

I understand your point about the scoring that if a blade is 10% better then it should be reflected in a 10% better blade score (i.e. Part 1 score). This however would only contribute 5% to the total score because of the 50/50 weighting between the two parts of the event.

I believe there was an early explanation that the goal was to reflect the power captured, however it seems that the power generated by the turbine is small compared to the wind energy from the fan, so it does not seem to accurately reflect on the blade performance. Commercial turbines are measured in power but they extract up to 30% to 40% of the wind energy. The best I have seen in this event is less than 2% of the wind energy.

To illustrate the original point the top three Part I scores at our state finals were 50 (of course), 24.8 and 9.9 with the other 26 teams below that. (This made the written portion almost moot for the top two teams). While the performance of the top 2 blades were good the final scores don't seem helpful.

If you want to argue that incremental changes are harder as the blade performance increases, I would have to agree, but I still think that using a point system proportional to the voltage would be an improvement.

I totally agree and that's pretty much that I have seen in invitational, regional, and State tournaments. The team with much higher voltage will pretty much guarantee the top places even they do fair or below average in the written part.

[lazyguy01]

4) A blade assembly with violations is still allowed to run (with the 15 point construction violation) because rule 4.c does not specify any consequence if the team does not fix the construction violation(s). This opens up an interesting situation if a team finds a way to increase their voltage score by at least 20% by breaking a construction rule ..... Maybe blade assemblies that don't meet the construction rules and don't / can't be fixed get zero in Part I (rule 5.f)
.

This is why I like to ask for suggestions / comments. The wording in 4.c. is supposed to prevent blades that don't meet specs from being tested, but I can see how it could be read otherwise.

Also what is the overall difference in score between a team that (a) has no blade, (b) has a blade with a construction violation that they correct, and (c) has a blade with a construction violation that they never correct? I would argue that without knowing specifics that I think B is the best of these, followed by C, and A being the worst.

Could the team with construction violation will automatically be in tier II? I have seen some team using commercial material (without major modification) to get a very good result that can benefit much more than the penalty.

[GoldenKnight1]

I totally agree and that's pretty much that I have seen in invitational, regional, and State tournaments. The team with much higher voltage will pretty much guarantee the top places even they do fair or below average in the written part.

But is that such a bad thing? And that is honestly a question that I don't know. If I had the best plane in Wright Stuff that crushed the competition should I not win? If your competitor beat you in Wright Stuff by flying an extra 30 seconds wouldn't it make you want to improve your plane to fly longer rather than change the formula that determines the ranking?

This event seems at the top to be run where the paper and pencil test score you receive keeps you competive so that the device score can win the day for you. It's About Time seems to be the other way around where the top teams have a clock that can get them 45-50 points and the test is the deciding factor. For IAT if you get a great score on the test and you have a reasonable clock you do very well. Wind is just the other way in which a great blade and a reasonable test will do well.

[PHXcoach]

Great question.
I would also add a consideration of how well the blade does, so that possibilities are:
a) blade assembly with no violations achieves highest voltage
b) blade assembly with no violations achieves 50% of high voltage
c) blade assembly with corrected violations achieves highest voltage
d) blade assembly with corrected violations achieves 50% of high voltage
e) blade assembly with uncorrected violations
f) no blade assembly

Lets assume rule 4.c is clarified to prevent any blade assembly with uncorrected violations from being run.

(a) is straight forward

I would like (f) to score no higher than any other condition. Right now it would score 0 points.

I would like (e) to score no lower than (f), but no higher than any other condition - i.e. you are not worse off taking a blade to a competition than having no blade. If the blade was not allowed to run then this would be a -15 pt score.

(d) is interesting - we had some of these - where the blade score ends up being negative because the 15 point construction violation was larger than the voltage score. I would like to see this be not lower than an unfixed blade or not bringing a blade at all.

I think that I have only seen one blade with a correctable violation that scored well, and in that case the 15 pt penalty seemed fair, but with only one case I don't have a lot to go on to compare cases (b) and (c).

So I think the two cases I am concerned about are:
1) blades with uncorrected violation - which could just be given 0 voltage score and a construction penalty
2) teams with no blade assembly - this current scores better than a blade with unfixed violations (e) or a blade with fixed violations that gets less than 50% of the maximum voltage (d)

So I think the only remaining problem (other than clarifying rule 4.c) is that someone not bringing a blade (f) can do better than teams that bring a violating blade (d) and (e). Maybe giving teams with no blade the same 15 point penalty as the construction violation would address this.

Generally the variability of generators and fans has made comparing results from different states difficult. It will be interesting to see how teams nationals scores compare to their state scores.

[PHXcoach]

With respect to the Wright Stuff comparison - I understand your point, but they don't square the flight times !

[finagle29]

With respect to the Wright Stuff comparison - I understand your point, but they don't square the flight times !

Additionally, nobody has requested that the square root of the times be used to rank teams. Again, I'd like to point out that (IMO) power is a more fundamental measurement of how good a wind turbine is than voltage. Voltage can be increased and decreased by an ideal transformer, but power remains constant. A wind turbine that is twice as efficient (taken to mean having a power coefficient two times greater) as another one will extract twice the power, but only times the voltage across the same resistor. Scoring teams based on voltage rather than power is akin to taking the square root of the ratio of their efficiency to the best team's efficiency, something that just makes less sense to me.

[0ddrenaline]

I understand what lazyguy01 is saying. From the competitions I've been to, the teams on the very top are separated from lower teams by their blade score, while lower teams are separated from each other by test score. However, whether or not you see this as a problem is a matter of opinion. I personally don't mind that the blade score matters very much. I still have to do well on the test, but a single wrong question usually won't determine the difference between 1st and 3rd, which may happen at some competitions in study events. It seems fair to me.

[0ddrenaline]

I understand what lazyguy01 is saying. From the competitions I've been to, the teams on the very top are separated from lower teams by their blade score, while lower teams are separated from each other by test score. However, whether or not you see this as a problem is a matter of opinion. I personally don't mind that the blade score matters very much. I still have to do well on the test, but a single wrong question usually won't determine the difference between 1st and 3rd, which may happen at some competitions in study events. It seems fair to me.

[lazyguy01]

With respect to the Wright Stuff comparison - I understand your point, but they don't square the flight times !

Additionally, nobody has requested that the square root of the times be used to rank teams. Again, I'd like to point out that (IMO) power is a more fundamental measurement of how good a wind turbine is than voltage. Voltage can be increased and decreased by an ideal transformer, but power remains constant. A wind turbine that is twice as efficient (taken to mean having a power coefficient two times greater) as another one will extract twice the power, but only times the voltage across the same resistor. Scoring teams based on voltage rather than power is akin to taking the square root of the ratio of their efficiency to the best team's efficiency, something that just makes less sense to me.

In this competition, all team are using the same setup (same resistor, motor, fan) and what they are focusing or seeing is voltage. The higher the voltage, the more power it will generate. When the judge record the reading, they record the voltage and based on that, they can pretty much tell the different. By squaring the different, it just make the points gap much bigger than the written part. I will see all the teams will pretty much spend most of the time focusing on making the more efficient blade assembly than studying the topics. If they are using different setup (just like real world), then I see the point to use power as the calculation.