Expandable Wing Projectile

[daxspudder]

3 does not work well... don;t ask me why I read it long time ago - anyway have you seen any rocket that has 3 tailwings ?

No. But a this is more of a missile in concept, which is more like an airplane, and last time I checked, every commercial airliner has 2 ailerons and 1 vertical stabilizer aka 3 tailwings

[sandman]

anyway have you seen any rocket that has 3 tailwings ?

The Space Shuttle

[daxspudder]

anyway have you seen any rocket that has 3 tailwings ?

The Space Shuttle

good call

[sandman]

just have to make a point, and if u guys still dont believe me, i can get out the rocket simulation software

[daxspudder]

I believe, that is why I designed it that way

[sandman]

i know, but others doubt us

[Gippeto]

I built many a model rocket in my younger days.

Being a "typical" teenager (no offence), it didn't take long to figure out that making 3 fins took less time than 4.

All my rockets worked just fine with only 3 fins. I guess they never read that book either.

[LynyrdSkynyrd]

now the question is: will a rocket design work the same at an angle as it would vertical?

I guess i'm just wondering if the front would dive b/c there's nothing to hold it up...

i could be completely wrong tho... i'm not an aerospace engineer or anything...

[POLAND_SPUD]

hmmm that's what I read... it might be wrong - but if that is the case why the book is considered to be a milestone... lol there were very few people experimenting with rockets in 17th century....

I have to do some research if I find something that supports my claim I'll post it here...

[LynyrdSkynyrd]

I think to get the projectile to fly right with fins at an angle it needs to be spinning at a fairly good rpm. at least i'm pretty sure thats how those armor piercing tank rounds work.

[POLAND_SPUD]

nahhh... AFAIK APFSDS rounds don't spin

[psycix]

Angled fins to make it spin will only increase resistance and slow the projectile down. Spinning the round is simply not needed because you already have fins.

[jackssmirkingrevenge]

nahhh... AFAIK APFSD rounds don't spin

True, in fact those designed to be fired from rifled barrels have a slipping driving band (between the barrel and the sabot) to prevent spin being transfered to the projectile. Any rotational kinetic energy imparted on the projectile detracts from the linear kinetic energy of it's motion, and when you're trying to penetrate over 12 inches of angled tank armour, you need ever fraction of a ft/lb of energy you can muster.

This is also applied to some fin-stabilised HEAT rounds, as a rifled projectile tends to disperse the jet from the shaped charge through centrifugal energy, decreasing its effectiveness.