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Is Mach 2 possible on a D21?

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ScrapDaddy

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I'm not an idiot I know this would be EXTREMELY HARD but I'm wondering if this would be possible..and if you just happened to have a design for this just happened to have a rocksim design file laying around for one of these please share : D :roll:
 

dave carver

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Used to be you could put a E25 into a Zinger and pop Mach but I don't know about the D21.
 

JDcluster

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You could do a Estes Alpha on a Vulcan G 200, that's if you can find a G 200.....


WRASP says Mach 2.22



JD
 

The EGE

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In a rocket: no.

Under absolutely optimal and impossible conditions - 5g rocket, minimum diameter, 0.25 Cd - the maximum vertical speed is about Mach 1.6, or 550 mps.

Under ideal but plausible conditions - 12g rocket and 0.4 Cd - The best you can get is a hair over Mach 1.2, or 410 mps.

A more reasonable estimate, for a rocket that's not absolutely polished and built to actually survive supersonic flight, is 18g and 0.55 Cd, which gets Mach 1.1; 370 mps.

(All figures run with RASP. Rocksim will deliver similar results)

The only possible way to get a D21 to Mach 2 (690 mps) is on a frictionless, massless rocket sled in a vacuum, where the motor could accelerate itself to 960 mps (Mach 2.8).

The smallest rocket that can get to Mach 2 without a perfect rocket is prolly the AT J570W, or similar CTI loads. Those require L2 certification, though, and a very large field as they'll put a 18 oz minimum-diameter bird to some 13000 feet.

For now, I'd suggest sticking to Mach 1 as a reasonable, if difficult, goal.
 

cjl

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The G200 is definitely OOP.

As for mach 2 on a D21? I'd say that no, that's not possible. There's simply not enough power. Even mach 1 on a D21 is difficult. A realistic minimum for achieving mach 2 is something along the lines of the Aerotech I600R or CTI I540 WT.
 
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The EGE

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Yes, the G200 is OOP. The highest-thrust 24mm motor currently available is the AT F39, though the lighter SU F32 would be better for 24mm mach attempts.
 

ScrapDaddy

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yeah i had doubts that it was possible : / i guess ill just keep this on my whenever better 18mm motors come out list, and i just noticed there isnt much of a market for 18mm composites is there a reason?
 

Initiator001

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Twenty yars ago, I built a lightweight rocket powered by a D21 for the velocity trials event held at El Dorado Dry Lake outside of Las Vegas, NV.

After the data was reviewed, my D21 model had reached a velocity of Mach 1.019. Just made it. :D

The 'fastest' flight of the event was a minimum diameter 29mm rocket built by Scott Pearce and powered by an AeroTech G300-P motor. It reached a velocity of Mach 2.19.

Mach 2 with a D21? Not possible, it can barely reach Mach 1. ;)
 
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