Elastic Launched Glider C

[JonB]

I am well aware of the FAQ posted about "(no) aerodynamic surfaces may be behind the main wing". Would a "V" tail be considered an aerodynamic surface if it has no airfoil?

I feel it would provide lift at some point of the transition/flight (even with no angle of attack when gliding), but correct me if I am wrong.

[jander14indoor]

As usual, opinion, not official answer, post question to the NSO website, etc...

A surface needs no airfoil to provide lift/be aerodynamic. Just as an example, look at the Simple Simon glider, flat plate wing and it flies just fine. Making it a V doesn't change it's characteristics. I suspect if you have any significant surface area when projected to the horizontal plane it will not count as a canard.

Jeff Anderson
Livonia, MI

PS, if Brian's times are without bonus, I suspect that's a VERY competitive design. I watched some very pretty conventional fliers this weekend and the best got consistent 23 second flights in that 40 ft gym without getting any higher than 30 ft, if that.

[Smithy0013]

I am well aware of the FAQ posted about "(no) aerodynamic surfaces may be behind the main wing". Would a "V" tail be considered an aerodynamic surface if it has no airfoil?

I feel it would provide lift at some point of the transition/flight (even with no angle of attack when gliding), but correct me if I am wrong.

again opinion (I'm just a student) but if I were running the event i would say no to that. Because it becomes messy with at what point does it stop becoming a V tail and is simply a horizontal stab with dihedral? 45 degrees? less? more? Also assuming they are flat plates, they would need to fly perfectly straight into the airflow to not generate lift. This would be practically impossible to do since any time the glider has any changes made in direction, theyre gonna be doing something to affect pitch. But again it's just an opinion. Although if Im wrong thatll make this whole canard thing that much easier

[jander14indoor]

<SNIP>Although if Im wrong thatll make this whole canard thing that much easier

Not much risk of being wrong there...

And the whole POINT of a stabilizer is to react by providing force to counteract change when perturbations in flight occur. Which a flat plate V tail will do.

And yes, that's still an opinion.

Jeff Anderson
Livonia, MI

[elg4]

Does anyone have information about the dimensions at nationals glider will be flying in?

We looked up the location and it is the Arena Lobby but could not find the dimensions.

[_HenryHscioly_]

8.6 meters high, 28.75m long, 13.85m wide
how would times of 22-23s fair?

[musicalcoconut]

Does anyone have information about the dimensions at nationals glider will be flying in?

On the nationals website it says the area is 38 feet tall. I don't know the floor area though.

[jander14indoor]

At a regional last weekend I observed some nice flying gliders, the best team was in the 23s. Ceiling height was around 40 feet, similar to the national site. But frankly there was a lot more time in their gliders. They were only getting about 2/3rds of the way to the ceiling where they transitioned. If they'd transitioned 10 ft higher they would have been in the low 30s at least.

After the official scoring they tried to get higher, but I don't think they had any practice at higher sites and had trouble dialing in launch and trim parameters to get a good transition as they went higher. Thus the importance of practice at multiple heights.

And their gliders were not down to 3.0 gm so I suspect it will take 30 to 35 to win nationals.

Oh, that's per flight. Aggregate, 90+.

Jeff Anderson
Livonia, MI

[Smithy0013]

At a regional last weekend I observed some nice flying gliders, the best team was in the 23s. Ceiling height was around 40 feet, similar to the national site. But frankly there was a lot more time in their gliders. They were only getting about 2/3rds of the way to the ceiling where they transitioned. If they'd transitioned 10 ft higher they would have been in the low 30s at least.

After the official scoring they tried to get higher, but I don't think they had any practice at higher sites and had trouble dialing in launch and trim parameters to get a good transition as they went higher. Thus the importance of practice at multiple heights.

Well you have to realize that a lot of people don't have the facilities to practice in a forty foot gym. I know my gym isn't close to the height we faced at regionals and if we did take full advantage of the height i think we could have knocked first off of its pedestal. Also simply getting the glider to get higher you have to sacrifice a bit of the LD most of the time which makes it complicated in terms of how much time they would actually get.

[jander14indoor]

I recognize how hard this event is. And the mention of height was to emphasize how important it is to test against multiple ceiling heights, you will have difficulty getting there at the tournament.

But by the time you get to nationals several teams will have it nailed so I'm just using that regional's results as a point of reference to answer the previous poster's questions about how 23 seconds will fair at nationals. Good, not likely to win, might medal, there can be a big drop between 1st and 6th. Opinion based on limited evidence.

Regards,

Jeff Anderson
Livonia, MI