GLR Mariah 54 - Block 3 Video Build

bobkrech said:

SinfulDarkLord needs to do some homework. CCotner is correct, however the occurrence of buckling at the Mach transition is just coincidental.

Column buckling failure of airframes is a well understood phenomenon, but not by the weekend launcher. It happens more than you think and a good example is the TRF archive reference below to a LOC Weasel column buckling failure on a Cesaroni I-540 at NERRF 3 that I analyzed for Boris Katan.

https://www.rocketryforumarchive.com/showthread.php?t=45337

Aeroelastic loads cause vibrations in the airframe which couple with the aerodynamic pressure loads and inertial loads created by high thrust motors to create a buckling failure in a minimum diameter airframe at the top of the motor casing which acts as a stress concentrator. The failure occurs with the top of the rocket folding over and being ripped off by aerodynamic forces.

Airframe column buckling failure is due to high velocity dynamic pressure loading and/or high acceleration inertial loading of a vibrating airframe and is due to a lack of airframe stiffness, not a high angle of attack. It is prevented by stiffening the airframe by inserting a full length coupler inside the airframe to stiffen it, or by wrapping the airframe with FG or carbon.

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That is true, but much more common with paper or LOC tubing. It is not as common with Blue Tube or Magna Frame.

bobkrech said:

Aeroelastic loads cause vibrations in the airframe which couple with the aerodynamic pressure loads and inertial loads created by high thrust motors to create a buckling failure in a minimum diameter airframe at the top of the motor casing which acts as a stress concentrator. The failure occurs with the top of the rocket folding over and being ripped off by aerodynamic forces.

Airframe column buckling failure is due to high velocity dynamic pressure loading and/or high acceleration inertial loading of a vibrating airframe and is due to a lack of airframe stiffness, not a high angle of attack. It is prevented by stiffening the airframe by inserting a full length coupler inside the airframe to stiffen it, or by wrapping the airframe with FG or carbon.

Bob

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cwbullet said:

That is true, but much more common with paper or LOC tubing. It is not as common with Blue Tube or Magna Frame.

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I am no where near as eloquent as Bob nor due I have his knowledge or education, but I do have years of experience, seeing most of this stuff happening & understanding it....all for the wrong reasons...Lol but learning from them.

Us old timers call this...... "finding the speed of paper" meaning that speed at which it will go no further.

Several years ago a couple of my buddies tried an experiment to prove this: [yeah Mike this means you & JB!]
They had a contest to see who could break Mach, closest to the ground. [before Warp or V-max]
Built a rocket called "Shred Me" and began to stuff various motor in it starting with K-550's then reds & blues.
Hit the wall with the K-1100 blue thunder. Got to mach around 1000ft [If memory serves] but shred me imploded.
self destructed, other configurations were built, all paper or phenolic, double coupled, double walled, etc.

But after Shred Me 1 and finally Shred Me 2 [or 3?] no paper rocket could get them past the realm of a brute K-1100 [or might have been the red 1275?] They had G-whiz on board for data, any how after the last flight, which I was standing under, when it imploded at 700ft, and rained down all the debris from a spectacular shred, nothing but small pieces.
We all had a good laugh & they finally decided that after many attempts with different configurations........ we
"found the speed of paper".....

Many others have tried before & since....now there is Magna & bluetube....so the bar has been raised a bit....BUT without any re-enforcement......you too will find the speed of paper/fin flutter. Now you know "the rest of the story" & why I suggested a smaller K before the L due to seeing 2 of these find the "speed of paper" with L's un re-enforced.

Once again good luck with your experiment and "Shred Me 4"...Lol

I hope it survives....really I do.

PS Bob.... I was there and remember the Boris flight/posts AND learned a lesson or 2 from that also!

Thank for clarifying that. I never said it wan't possible. I want trying to say it is more common with higher thrust motors.

CCotner said:

That makes a ton of sense, thank you. I was trying myself to to figure out how the failure could have occurred, because the straight-up drag force was no where near enough to buckle the tube. I need to teach myself a good way to model that kind of behavior for my N5800. Bob, do you have a good resource? A quick look through the index of Anderson's compressible flow textbook didn't turn anything up. I have access to Ansys Fluent but am in the infant steps of teaching myself how to use it.

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Here's a paper on the topic. The stimulus is different but the math is the same. It's too long to be attached if you want a copy send me an e-mail and I send you a copy.

Bob

Internal References

1 Composite Bottle Thermomechanical Failure Analysis , ARA viewgraphs, courtesy of Stead Howie. Q16

2 Fung, Y.C., E.E. Sechler, and A. Kaplan, XX (Sept.), 650 (1957). Q17

3 Lindberg, H.E., and Y.D. Murray, Aptek Report, February 24, 1988.

4 Love, A.E.H., A Treatise on the Mathematical Theory of Elasticity, 4th ed., p. 454, Dover, New York (1927).

5 Mirels, H., “Vibration of Pressurized Thin-Walled Cylinder Induced by Pulsed Laser—Addendum”Aerospace Report TOR-2001(1019)-1, August 2002.

6 Mirels, H., and K. Zondervan, “Vibration of Pressurized Thin-Walled Cylinder Induced by Pulsed Laser,”Aerospace Report TOR-2001(1019)-7, 29 July 2002.

7 Rayleigh, Lord, Proc. Cambridge Phil. Mag. 5th Series, Sec. R., Vol. VII, 101 (1890).

8 Saada, A.S., Elasticity, p. 138, Pergamon, New York (1974).​

9 ​

​

Sutton, G.W. “High Energy Single Pulse Laser Structural Damage of Cylindrical Shells,” 10th Annual AIAA/BMDO Technology Conference, July 23–26, 2001.​

​

Rocksim for the Mariah 54, Enjoy.

View attachment GLR Mariah 54 B3.rkt

SinfulDarkLord said:

Flights tomorrow, hopefully all goes well. Will be posting some videos of other flights. One is a N5800 challenge and the other is a N-to-N to 100,000 feet.

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When from?

This is beginning to sound like one of those catastrophies you cant look away from. op:

SinfulDarkLord said:

Flights tomorrow, hopefully all goes well. Will be posting some videos of other flights. One is a N5800 challenge and the other is a N-to-N to 100,000 feet.

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Not to bother you, but I'd love to see any video you did get...

I was actually interested in seeing the shred.

SinfulDarkLord said:

Apparently they were trying this new wireless launch station and somehow even though the safety key was off it launch the rocket and we had no warning.

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holy crap that's terrifying. Was anyone hurt?

There go our tentative plans to launch in New Mexico...

Malfunctioning wireless launch equipment? Over my dead body... ...maybe I'm paranoid. Also, 200' << minimum safe distance for a N, let alone the complex distance for an N, which is probably what any N5800CS Minimum Diameter deserves.

The timing of launches is kind of bad, too. Fourth Sunday means that even if I go out on my spring break, I have to book it back to LA on I10 that evening and won't make it back until mid-morning on Monday. And that leaves no time for recovery if it drifts far.

That is Terrible that the launch was scrubbed. I will hope for Feb. Please do video.

My Mariah 54 is complete. Two more videos are on the way to finish the video build. To be honest it's not finished yet. I still need to glue in the super mount, but I am waiting to see if I can get a 6GXL casing. I got a little creative and made an internal motor retention, but I need to measure where it needs to be glued at.

The video build is somewhat complete. I hope a lot of you will enjoy watching these videos. Will have one more to come, but will be later on once I get a 6GXL casing .

Realizing I did not mention the Shock Cord anchor much except on one post that doesn't show much. I decided I would post some more information on how I changed the Shock Cord Anchor into an internal motor mount. In the case that you get a Mariah 54 this will allow you to not spend money on a more expensive alternative.

Mainly the Shock Cord Anchor is a coupler with a wooden dowel in the middle. I simply drilled a hole through it and passed a 5/16" threaded eyebolt and at the same time added a 1/4" thick bulkhead. The results is a really cheap internal motor retainer ready for your Mariah 54. I glued the nuts together with 5 Minute epoxy, then glued the eyebolt passing through the wooden dowel with JB Weld and finally I made a fillet around the bulkhead (not shown in picture).

Pictures:

Nice job Alexander.

SinfulDarkLord said:

Rocksim for the Mariah 54, Enjoy.

View attachment 107532

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You have the Mariah weight at 40 oz is that what yours built up to? Mine is 3 lb 10oz

Highfly said:

You have the Mariah weight at 40 oz is that what yours built up to? Mine is 3 lb 10oz

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Is yours the one with the filament wound fiberglass airframes?


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

Yes it is I imagine that's the difference.

Highfly said:

Yes it is I imagine that's the difference.

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Yes mine is the magnaframe version. That explains the weight difference.


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

During ground testing with the glass frame, ended up with 1.7 grams black powder for separation using 2 2-56 sheer pins. First light went well on a two grain 54mm CTI motor for ) 6300 feet. System worked perfect. Next flight will be on a K300 long burn for somewhere around 24000 ill keep you up how it goes.

Highfly said:

During ground testing with the glass frame, ended up with 1.7 grams black powder for separation using 2 2-56 sheer pins. First light went well on a two grain 54mm CTI motor for ) 6300 feet. System worked perfect. Next flight will be on a K300 long burn for somewhere around 24000 ill keep you up how it goes.

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Good luck, please do post your results.


Alexander Solis

Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet