Multiple Parachutes?

[Ground_Control]

Hey all. I'm putting together a custom large copy of one of my all time favorites the Estes Ram Jet. The issue, as with the original, is space inside the MMT. The MMT/center body tube is 18mm (BT20) and getting a 24 inch parachute in there without packing it in like a musket ball is near impossible. I was thinking of using a pair of 12" chutes one located at the nose and the other near the main body. There's plenty of shock cord and they can be easily separated internally so they shouldn't interfere with each other during deployment. Thoughts? Pictures below should illustrate the size differences between the original and the bigger version. The larger is setup for an 18mm composite motor.

 

[Sooner Boomer]

Two 12" chutes should actually give you more drag (slower recovery) than a single 24". You can always test your rocket by packing it loke you would for flight and putting it up to your mouth and trying to blow everything out. This might not taste very good with a rocket that has flown, but it will give you an idea how much force it takes to clear the tube.

 

[SecondRow]

Two 12" chutes should actually give you more drag (slower recovery) than a single 24".

Can you explain this? Maybe I don’t understand specific properties of parachutes, but a 24” parachute has roughly twice the surface area of two 12” chutes. Doesn’t that mean the 24” gives more drag?

 

[Sooner Boomer]

Can you explain this? Maybe I don’t understand specific properties of parachutes, but a 24” parachute has roughly twice the surface area of two 12” chutes. Doesn’t that mean the 24” gives more drag?

Probably. *sigh* should not post technical stuff in the middle of the night.

 

[David Schwantz]

I would have to guess that if the chutes were not attached at the same point, the one closer to NC will not inflate fully as the other having to support the weight of the booster will.

 

[SecondRow]

Probably. *sigh* should not post technical stuff in the middle of the night.

I’ve been there.

 

[BABAR]

I would have to guess that if the chutes were not attached at the same point, the one closer to NC will not inflate fully as the other having to support the weight of the booster will.

I don’t know about nylon chutes, but I’d agree that getting two PLASTIC chutes attached to one rocket BOTH fully deployed is hard, once the first one inflates it slows down the airstream and the second in my experience frequently at least partially streamers.