Advice Needed for school project

[lowerstoford]

The Rules!!!

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[bugwubber]

The Rules!!!

WP_20140225_19_57_58_Pro (2).jpg

Actually, my design still complies with the rules. Ignore that drawing of one fin.

As for a large wing or not, I got more altitude but a crash with no more distance.

[youtube][/youtube]

[lowerstoford]

Interestingly our test flights look to have traveled further than yours.
As it was pitch black, the videos only show lift off
What distance did you reach? Approximately

[bugwubber]

Be careful about comparing vs mine, I'm launching with snow instead of water. Its 3 degF outside.

[Water Rocket Expert]

Can't they build a simple cable tie launcher and make it better. It says you can't have fins on all sides because it won't fit on the launcher.

EDIT: Sounds more like a jet propelled airplane contest.

[bugwubber]

Can't they build a simple cable tie launcher and make it better. It says you can't have fins on all sides because it won't fit on the launcher.

When you aren't going up, it doesnt make sense to have fins on all sides. Need to start thinking like a jet pilot.

[Water Rocket Expert]

That's not completely true. If the rocket had a 2 mm nozzle, well then that is fine, but his has a full bore. It would be like putting 5 space shuttle boosters on a piper cub and saying since it is going horizontal it does not need fins on all sides. If the fins are big enough that it can glide when you throw it, they'll likely be destroyed in flight, where as if there stream line and swept then they won't produce enough life when it slows down, do your better of with more "wings" on all sides so that it will be more stable and so that it's speed will last longer.

[Water Rocket Expert]

I know planes like the SR-71 exist but they maintain the thrust so small wings don't matter.

[bugwubber]

I know planes like the SR-71 exist but they maintain the thrust so small wings don't matter.

The F-14 or NASA's new shape shifting swing wing design would be an ideal model. Low drag during high speed thrust phase, high lift, low stall speed during slow glide.

Fins on all sides will only guarantee the projectile will follow a ballistic arc. If you want to do better than a ballistic arc, you will need to trade some of your energy for lift.

This of course means you need the rocket to stay oriented in one direction. A high wing with winglets or wings with dihedral are a reliable way to do this. Loading your ballast along the bottom will also help with that orientation.

I totally forgot I made a launcher that will demonstrate models side by side. I'll launch from that tomorrow.

[Water Rocket Expert]

The problem is the high amount of thrust.

[bugwubber]

Interestingly our test flights look to have traveled further than yours.
As it was pitch black, the videos only show lift off
What distance did you reach? Approximately

I'm launching fairly level as I'm trying to keep them from going too far. I think now that is penalizing the ballistic rockets. Only had one shot since everything iced up afterwards.

[youtube][/youtube]

[Water Rocket Expert]

We now have been getting so much snow recently, it's unbelievable.

[WRA2]

We now have been getting so much snow recently, it's unbelievable.

Yea. All those "global warming" believers should come and pay my heating bill.

[bugwubber]

We now have been getting so much snow recently, it's unbelievable.

Yea. All those "global warming" believers should come and pay my heating bill.

Or at least come dig out a place for the poor pooch to go!

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[bugwubber]

Anyway, good luck tomorrow lowerstoford! Keep us posted on how it goes.