shutting down a solid rocket.

[LARRY A ROSA]

I see multiple obvious problems here.

-This clamshell nozzle that you're so jazzed about is overly complex. Just jettison the nozzle if you have an emergency. That will release all the chamber pressure and result in the loss of thrust. Such a system will be a lot simpler and, more importantly, more reliable. Hydraulics fail much more often than ordnance does. You also won't have the problem of holding that nozzle closed against hundreds of PSI of chamber pressure, and a clamshell nozzle, if built, would have to be 100% totally sealed when closed, with nothing leaking through the seam between the halves while the motor operates. Leakage would, at best, result in significant efficiency losses or, at worst, wreck the nozzle and anything near it. Preventing this leakage against the chamber pressure of a rocket motor/engine presents a significant problem.

-The melting point of a substance is not the point at which it will fail due to heating. Materials can lose their strength when heated excessively even if they are not close to melting.

-The RL64 engine is fueled by hazardous hypergolic chemicals that you don't want anywhere near a driver or spectators, namely hydrazine and red fuming nitric acid. The Jayhawk also achieves its range and speed flying at a high altitude and being a small, light drone vehicle that weighs only a few hundred pounds. You can't just strap the same engine to a different vehicle and expect similar performance.

-You have a lot of other problems besides propulsion - aerodynamic drag being a major one, and also how you're going to prevent the whole thing from flipping over as you create shock waves between the car and the ground. 1600 mph is above Mach 2. There's a reason why supersonic aircraft typically also fly very high - the air is thinner and produces a lot less drag. Supersonic driving has been done once. This was back in October 1997, using a pair of Rolls-Royce jet engines that produce much more thrust than any motor we're going to be talking about here, and that barely broke Mach 1. You're talking about doing something that is going to require professional engineers and a huge amount of funding. It is well beyond the scope of a hobby forum.

that chamber will never close........ no one is that $%#%$# come on...... it is easy to open and close the all steel nozzle with a hydralic system (again)..... that is all it moves......full open to return to the (1) size nozzle.

full on or off......... thats it (again) ...... the whole reason is to stop all thrust...... there is ABSOLUTLY NO WORRY FOR AN EXPLOSION...... on/off.

if that hasen`t answered your question...... you can listen to BLACK SABBATH on these wicked altec lansing whorns ?

R-A-T-H-E-R......... here here ......

 

[LARRY A ROSA]

Just rig the motor with releases so instead of shutting it down you just let it fly off on its own?

idiot idea......... don`t you think...... let it fly off. huh.........h e y ?

 

[LARRY A ROSA]

I see multiple obvious problems here.

-This clamshell nozzle that you're so jazzed about is overly complex. Just jettison the nozzle if you have an emergency. That will release all the chamber pressure and result in the loss of thrust. Such a system will be a lot simpler and, more importantly, more reliable. Hydraulics fail much more often than ordnance does. You also won't have the problem of holding that nozzle closed against hundreds of PSI of chamber pressure, and a clamshell nozzle, if built, would have to be 100% totally sealed when closed, with nothing leaking through the seam between the halves while the motor operates. Leakage would, at best, result in significant efficiency losses or, at worst, wreck the nozzle and anything near it. Preventing this leakage against the chamber pressure of a rocket motor/engine presents a significant problem.

-The melting point of a substance is not the point at which it will fail due to heating. Materials can lose their strength when heated excessively even if they are not close to melting.

-The RL64 engine is fueled by hazardous hypergolic chemicals that you don't want anywhere near a driver or spectators, namely hydrazine and red fuming nitric acid. The Jayhawk also achieves its range and speed flying at a high altitude and being a small, light drone vehicle that weighs only a few hundred pounds. You can't just strap the same engine to a different vehicle and expect similar performance.

-You have a lot of other problems besides propulsion - aerodynamic drag being a major one, and also how you're going to prevent the whole thing from flipping over as you create shock waves between the car and the ground. 1600 mph is above Mach 2. There's a reason why supersonic aircraft typically also fly very high - the air is thinner and produces a lot less drag. Supersonic driving has been done once. This was back in October 1997, using a pair of Rolls-Royce jet engines that produce much more thrust than any motor we're going to be talking about here, and that barely broke Mach 1. You're talking about doing something that is going to require professional engineers and a huge amount of funding. It is well beyond the scope of a hobby forum.

 

[LARRY A ROSA]

that chamber will never close........ no one is that $%#%$# come on...... it is easy to open and close the all steel nozzle with a hydralic system (again)..... that is all it moves......full open to return to the (1) size nozzle.

full on or off......... thats it (again) ...... the whole reason is to stop all thrust...... there is ABSOLUTLY NO WORRY FOR AN EXPLOSION...... on/off.

if that hasen`t answered your question...... you can listen to BLACK SABBATH on these wicked altec lansing whorns ?

R-A-T-H-E-R......... here here ......

i guanrantee that these will put you way farther in the universe that a pee wee rocket will. hahahahahahaha.....ha !

 

[LARRY A ROSA]

crazy thought: sequenced sequential motors, abort stops next from firing

not real sure...... is that what i should do...........

 

[Antares JS]

I'm not sure why you quoted me when saying your chamber will never close. I never said your chamber was likely to explode. I will mention though, that "no one is that stupid" is an assumption that is consistently proven wrong.

If you're hell-bent on doing this crazy stunt, your best bet is to use a liquid or hybrid system that you can turn off simply by shutting off the propellant flow with a valve or two. If you must use a solid, make a one-piece nozzle that can be jettisoned by a simple piece of ordnance. You're talking about a safety system here and a safety system must be the simplest, most reliable thing possible. Your clamshell nozzle is far from fitting that bill and introduces a failure mode where exhaust leaks out the seam between the halves and compromises the nozzle.

I am going to say this though: Some random guy working out of his shed is not going to be the one to drive a car at Mach 2. Maybe you have a professional engineering team, millions of dollars at your disposal, and are readying a model for supersonic wind tunnel testing at Arnold AFB. I don't know. I'm definitely not getting that impression though.

Even if you are a pro and this is a serious project, the point stands that you're in the wrong place. This forum is for hobbyists who follow safety rules that forbid this stunt.

 

[FredA]

This forum is for hobbyists who follow safety rules that forbid this stunt.

Interesting comment -- having seen outhouses, tikibars, snowmobiles, etc. launched at TRA events.....
Not on the same level as this "stupid stunt" but still "stunts."

 

[Antares JS]

Interesting comment -- having seen outhouses, tikibars, snowmobiles, etc. launched at TRA events.....
Not on the same level as this "stupid stunt" but still "stunts."

I didn't say "stunts" in general. I said "this stunt." Making weird things fly is silly to me and not something I am into, but it can be done safely by an amateur.

 

[ebruce1361]

that chamber will never close........ no one is that $%#%$# come on...... it is easy to open and close the all steel nozzle with a hydralic system (again)..... that is all it moves......full open to return to the (1) size nozzle.

Pardon me for saying so, but a couple of pages back you seemed to indicate that you intended to seal off the nozzle as the emergency shutdown system.

that hydraulic system is only used in the event of an EMERGENCY......... when it is nessasary to stop propulsion.

the hydraulic system is super powerful............ it smashes those 2 movable pieces together .

Now you're saying "no one is that $%#%" and that your hydraulic system will close the "all steel nozzle" which just a couple of days ago was

a new metal called TANTALUM

Add to that, your profile shows your birthday as being in 1956, so if:

besides that wing foot express is my car...... from 1961.

then you mean to tell us that you owned a record-setting rocket car at the age of five years old?

Listen, I admire your spirit in wanting to tackle crazy engineering challenges and wanting to push the envelope of innovation, but there is a difference between audacious and delirious. I hate to say it, but you are a long way from possible or even sane with this project of yours. I can't tell if you're a troll getting a good laugh at our expense, a kid trying to sound smarter than he really is, or someone who should be very careful building anything at all, but in any case I wish you well. Be safe, don't endanger yourself or others with anything unproven or untested, and learn as much as you can about REAL ENGINEERING and DESIGNING before you even start drawing a rocket car.

 

[SDramstad]

idiot idea......... don`t you think...... let it fly off. huh.........h e y ?

No more stupid then putting a solid fuel motor on a car. The bar for "stupid" is set pretty low on this thread.

 

[LARRY A ROSA]

I didn't say "stunts" in general. I said "this stunt." Making weird things fly is silly to me and not something I am into, but it can be done safely by an amateur.

later j man..... much later. understand.

 

[LARRY A ROSA]

No more stupid then putting a solid fuel motor on a car. The bar for "stupid" is set pretty low on this thread.

unles one can totally shut the rocket down .

 

[cerving]

later j man..... much later. understand.

The troll has left the building...

 

[ebruce1361]

unles one can totally shut the rocket down .

 

[LARRY A ROSA]

Pardon me for saying so, but a couple of pages back you seemed to indicate that you intended to seal off the nozzle as the emergency shutdown system.


Now you're saying "no one is that $%#%" and that your hydraulic system will close the "all steel nozzle" which just a couple of days ago was


Add to that, your profile shows your birthday as being in 1956, so if:
then you mean to tell us that you owned a record-setting rocket car at the age of five years old?

Listen, I admire your spirit in wanting to tackle crazy engineering challenges and wanting to push the envelope of innovation, but there is a difference between audacious and delirious. I hate to say it, but you are a long way from possible or even sane with this project of yours. I can't tell if you're a troll getting a good laugh at our expense, a kid trying to sound smarter than he really is, or someone who should be very careful building anything at all, but in any case I wish you well. Be safe, don't endanger yourself or others with anything unproven or untested, and learn as much as you can about REAL ENGINEERING and DESIGNING before you even start drawing a rocket car.

i responded to the question wrongly...... it must have been late....somehow i crossed up what i wanted to say...like super speedo ? stupid of me.......

here is what i wanted to say:

the 2 piece nozzle opens and closes like a jaw (?)...... after the jaw type jaw is opened and the propulsion has stopped due to a very large open space ....it is then smashed together by the hydralic system & returns to its original nozzle size.


some how i got that mixed up when i last wrote it down......

understand what your looking at now......a round hole that is on a test stand.....ok so far ?..... surrounded by metal....

now a press of a lever opens the 6" sq. metal with a 2 1/2 " hole...... it opens wide..... another lever closes the 2 haves of metal & returns it to 2 1/2" hole that is the nozzle...... simple to stop propulsion from the rocket nozzle..... i seen something like the above somewhere before..... i am 64 now so my black sabbath brain don`t work as it used to.


i will do this & post the finished metal jaw nozzle when it is done.

 

[LARRY A ROSA]

not real sure...... is that what i should do...........

who could be so stupid to close or try to close a rocket nozzle that is still live...... the only time the nozzle is closed is just before the rocket is fired or re-closed after the rocket has been fired.

 

[mrwalsh85]

The troll has left the building...

Spoke a little too soon, huh?

It seems that LARRY A ROSA either has multiple personalities or multiple folks responding under the same handle. Could also be that he thinks he is responding to others but really he is responding to himself...

I think maybe worth it to shut down this thread....

 

[ebruce1361]

understand what your looking at now......a round hole that is on a test stand.....ok so far ?..... surrounded by metal.

Huh? What? I'm not looking at anything in this thread related to a test stand whatsoever. No, I'm not okay so far. None of this makes any sense. I think Black Sabbath is the least of your worries.

 

[Antares JS]

unles one can totally shut the rocket down .

I realized you may not know this, but solid rockets CANNOT reliably be shut down. The best you can do is release the pressure inside the chamber by opening the case and hope for a flameout. It is entirely likely, however, that the propellant will just continue burning after this pressure release until none is left - not something you want in an emergency situation.

 

[Steve Shannon]

I realized you may not know this, but solid rockets CANNOT reliably be shut down. The best you can do is release the pressure inside the chamber by opening the case and hope for a flameout. It is entirely likely, however, that the propellant will just continue burning after this pressure release until none is left - not something you want in an emergency situation.

Correct, and if a person tried to close or restrict the nozzle to reduce thrust, it causes the pressure inside the motor to increase, which causes the burn rate of most solid propellants to increase exponentially, which causes the pressure to rise, which causes the burn rate to rise even more until the motor case bursts. That’s when the thrust stops. [emoji2962]

 

[LARRY A ROSA]

you may be right about that !
the shut down nozzle has been fully explained ......although not in detail yet.....


here`s one you may have never seen before...... 400 - mph

it is rocket powered.

 

[LARRY A ROSA]

any idea where i can get a manual for an aQm-37 ?

i don`t need one but i would like to study that motor until i know it by heart...... tiny motor.....mach 4.0 speed.....

i can build one of these all day, 2 of them guarantees a 700 mph.

plus there are a million other liquid/kero/ox.......engines that will operate & use a nozzle biggie to stop propulsion instantly after fuel shut off....

i would like all the information i can get on the aQm-37.....& each different model of that motor used...... mach 4.0 !

 

[boatgeek]

any idea where i can get a manual for an aQm-37 ?

i don`t need one but i would like to study that motor until i know it by heart...... tiny motor.....mach 4.0 speed.....

i can build one of these all day, 2 of them guarantees a 700 mph.

plus there are a million other liquid/kero/ox.......engines that will operate & use a nozzle biggie to stop propulsion instantly after fuel shut off....

i would like all the information i can get on the aQm-37.....& each different model of that motor used...... mach 4.0 !

jesus christ .

Um. The AQM-37 is a currently active target drone with a liquid fuel engine used to simulate incoming ICBMs. Since it's in the fleet right now, it's almost certainly classified. And how you get there is likely classified as well. You definitely can't buy one unless you have a general signing your requisition slips. You almost certainly can't make that motor either--if you were that good, you wouldn't be here talking about it.

Liquids and hybrids don't need fancy nozzle mechanics to shut down--they just turn off fuel and/or oxidizer. Lots of people have said that a hybrid would be your best option here. While designing a hybrid isn't trivial, it's far, far easier than a liquid engine and still has the value that it can be turned off by shutting down the oxidizer flow.

 

[cerving]

Spoke a little too soon, huh?

It seems that LARRY A ROSA either has multiple personalities or multiple folks responding under the same handle. Could also be that he thinks he is responding to others but really he is responding to himself...

I think maybe worth it to shut down this thread....

Yup, this is on par with the "I want to build a rocket to fly to space, what type of propellant should I use" threads...

any idea where i can get a manual for an aQm-37 ?

i don`t need one but i would like to study that motor until i know it by heart...... tiny motor.....mach 4.0 speed.....

i can build one of these all day, 2 of them guarantees a 700 mph.

plus there are a million other liquid/kero/ox.......engines that will operate & use a nozzle biggie to stop propulsion instantly after fuel shut off....

i would like all the information i can get on the aQm-37.....& each different model of that motor used...... mach 4.0 !

jesus christ .

Try Googling it... you can probably find it on a .cn or .ru site.

 

[LARRY A ROSA]

Um. The AQM-37 is a currently active target drone with a liquid fuel engine used to simulate incoming ICBMs. Since it's in the fleet right now, it's almost certainly classified. And how you get there is likely classified as well. You definitely can't buy one unless you have a general signing your requisition slips. You almost certainly can't make that motor either--if you were that good, you wouldn't be here talking about it.

Liquids and hybrids don't need fancy nozzle mechanics to shut down--they just turn off fuel and/or oxidizer. Lots of people have said that a hybrid would be your best option here. While designing a hybrid isn't trivial, it's far, far easier than a liquid engine and still has the value that it can be turned off by shutting down the oxidizer flow.

that is about what i thought, i visit the air and space musuem in D.C. ..... they have a huge library on the top floor of that museum...... it has almost every aircraft ever built ...... i think i will try then for the motor blueprints...... they may have a older one........ the that was there at air and space on the mall is now at another place now that i think of it, they should have left it there ......

as far as building one is the last problem........i am a machinest & once i understand it....... assembling it should be easy..... liquid ? is it now powered by the nitric acid & o2

 

[boatgeek]

that is about what i thought, i visit the air and space musuem in D.C. ..... they have a huge library on the top floor of that museum...... it has almost every aircraft ever built ...... i think i will try then for the motor blueprints...... they may have a older one........ the that was there at air and space on the mall is now at another place now that i think of it, they should have left it there ......

as far as building one is the last problem........i am a machinest & once i understand it....... assembling it should be easy..... liquid ? is it now powered by the nitric acid & o2

It's currently deployed military hardware. Plans won't be in the Smithsonian because they're classified. You *might* be able to find Space Race era engine plans at the Smithsonian, though those tend not to have been updated with all of the changes they made in production to make it work.

As far as building--that's a whole 'nother kettle of fish. Special materials, special procedures, etc. They can be done, but you'll need a lot of care and cleaning procedures to not burn your shop down with the oxidizer.

 

[LARRY A ROSA]

well i do not want to fly to space, i will be going to mars..... i plan to get my ticket from Space X...... as soon as they go on sale !
i do want those motors for personal use in LSR cars.

 

[LARRY A ROSA]

It's currently deployed military hardware. Plans won't be in the Smithsonian because they're classified. You *might* be able to find Space Race era engine plans at the Smithsonian, though those tend not to have been updated with all of the changes they made in production to make it work.

As far as building--that's a whole 'nother kettle of fish. Special materials, special procedures, etc. They can be done, but you'll need a lot of care and cleaning procedures to not burn your shop down with the oxidizer.

right...... that bell x-1 is an excellent car motor 4 of them will make near 2400 mph- 16 rockets.

the power for progress brochure has a verity of rocket engines displayed on the cover...... powerful , powerful , super powerful rockets..... simple to make to.

 

[CoyoteNumber2]

any idea where i can get a manual for an aQm-37 ?

It was really hard to find but this should help you out.

AQM-37

 

[LARRY A ROSA]

if i remember correctly that aQm-37 i saw in person in belmont shores....at a bicycle shop on the beach side of ocean drive hanging from roof...... the nozzle hole was little more in diameter than a quarter, 25 c......... and now that i look at the whole combustion chamber...... i remember that it was not cooled by surrounding fuel lines ..... its not cooled at all.....

with a main diameter of 5" & about 8" long...... this rocket is what simple to make in the home shop "IS".......

hell you could use any liquid fuil that will burn in it.......... i`ll have to make a few of these ....... sooner than later.