leedrill Posted February 11, 2014 Posted February 11, 2014 http://www.youtube.com/watch?v=WGHmevJvnM4 ive wondered how these stabilise themselves since being shown one by a mate is it just that the notches in the side of the empty cavity underneath the motor has the similar effect to fins or is the that these cut outs allow air in the side that is turning into the wind correcting it i cant get my head around this principal is there some one out there that can explain this too me in detail
kpknd Posted February 11, 2014 Posted February 11, 2014 I have seen flare rockets used in model rockets, but you need onboard deployment. The slotted tube looks like a good experiment for finless models, I might give it a try.
FlaMtnBkr Posted February 11, 2014 Posted February 11, 2014 I wonder if some of the gas is diverted out the holes and the gas stream acts like fins that the still air flows around. Or the horizontal component push against each other and keep the back from going sideways and somehow keeps it straight. What I have wondered is why some whistle rockets will fly mostly straight. I guess it is mostly in those saturn batteries and the long unfilled tube is what keeps it going straight similar to a stick. But I think I have seen short whistle rockets without a stick fly fairly straight.
psyco_1322 Posted February 12, 2014 Posted February 12, 2014 If you look at spent Saturn missiles, the short burn melts the hell out of the tubes, which cause their erratic flights. Rockets with out sticks usually don't fly very well. The para motors I have seen often look to have little ports in the side like a stinger, or in end around the nozzle. I would guess they are spin stabilized, but I have yet to recover one to see how they look after shooting. The motors seem to fly fine if you attached a stick to them.
leedrill Posted February 12, 2014 Author Posted February 12, 2014 the ones ive seen taken apart on youtube really have no signs of being spin stabilised and in the slow mo vids around i can find you can see no spinning on take off to a few meters not to say they arnt though but i do believe they arnt. though it does just seem the slots in the ass end are the cause of straight flights and the motor nozzle is up past them maybe the have a cyclonic action to them and i just cant see the whole thing spinning on take off
Mumbles Posted February 12, 2014 Posted February 12, 2014 Saturn missles also benefit from having the fuel mostly in the front end of the tube. They're naturally stabilized by air resistance just like darts and Jarts.
leedrill Posted February 12, 2014 Author Posted February 12, 2014 actually mumbles i think you have hit the nail on the head to my question the motor is up a fair way and the cut outs would have exaust gasses comeing out some what { unless they Venturi air in } but id assume that when it does stray from stable the cut outs allow air and exaust gasses to shift to the hole with the least pressure being the one that would some what help to correct its flight path still this is just my assumption if it is wrong please chime in if you have more knowledge
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