Thank you CopSub. I've been toiling for a while over a solid-fuel engine design involving sodium bicarbonate, and constructing the reaction chamber has been one of the most challenging things for me. This video actually revealed to me the physics behind the reaction chamber, and now I feel like a huge weight has been taken off me. Thank you once again, and good luck to Spica!
Thank you so much for your kind explanation and your are been absolutely amazing and fantastic and wishing you a success in your next rocket engine design
Really really appreciate this video, your project, and how hard you folks work to communicate about your effort and rocketry generally. Wish all of you on the Copenhagen Suborbitals team the very best of luck.
Very good video...I like how he kept it simple for the layperson....by the way the licking your finger on the hot plate reference to the fuel spray inside the engine is called latent heat....it's a physics property of liquid changing state and the heat it absorbs..
You're welcome! We have way more in depth rocket content around building them, if you are interested.
6 років тому+5
Thank you for sharing! You really inspire and help others to keep interested and helping. I love the expression that "rocket development is 95% banging your head with the wall and 5% success". Learning from mistakes is what lately make the success. Thanks and keep going!
Thank you so much for this explanation! You have simplified the subject matter and now I understand the cooling process. I wish you success and hope you can launch Spica soon!
Great video, im just curious how the high presure exhaust is controlled from going up and out the way the fuel came in? Since the presure is so high does that mean that the amount of presure the fuel is injected is higher thus preventing the exhaust re-entering the fuel pumps? Best regards
Thank you! :) What is the desired pressure in the nozzle? It low pressure / high expansion is more efficient, right? Never thought about that the nozzle has to withstand those high pressure levels so it doesn't implode. Very interesting!
There's really no general answer to that - it depends on the engines geometri, fuel types ect. And expansion also depends on ambient pressure a a given altitude. That's why second stage engines always have this huge engine bell :)
Have you ever thought about cooling the engine by brazing copper pipes on the inside of your combustion chamber? I mean obviously it would take a lot of man hours to do so, and very precise work to achieve repeatable results, but it would keep the engine cooler and might solve a few of the problems.
are you going to use the bpm-5/-design in a rocket/vehicle that will pass the karman like? like using the basic engine clustered or with a big engine bell in vacuum?
@@jackrigby6678 Hydrogen is extremely hard to work with and kerosene is not a very environmentally friendly option when we are launching rockets from the sea and risk large amounts of it being dumped into open waters.
I suppose that they feed the rocket wall jacket with cool fuel. They propably have multiple mounting point to cool the wall faster. If they fed fuel from bottom upward at a single point that could cause bad cooling distribution.
Would be good to have more structure data about it. How the built was approached, how to do the math, simulations, issues, and so one. A step by step tutorial with a knowledge center, so people across the world could self educate, replicate the rocket, and contribute.
You’d have to figure out how to pump it hard and fast enough. That basically requires turbo machinery of the highest degree or a really powerful electric motor (in the case of Rocket Lab’s Electron rocket)
Dollar Projects if you have a cnc or a 3D printer you can easily make an impeller that is power as required. The rocket is 60% plumbing (combustion cycle), 20% nozzle, 15% cooling, and only 5 percent everything else.
Small liquid rocket engines use high tank pressures from a secondary Nitrogen tank to generate the required fuel flow. If you're looking to build a really small engine, I would recommend reading www.cientificosaficionados.com/libros/cohetes.pdf If I had any mechanical knowledge I would absolutely build one myself. Alas, I work with computers instead.
Hi, it seems the throat is too wide and the nozzle too narrow and short. The mixture is ejected too soon out of the chamber and nozzle, and the combustion takes place too far away from the engine. In fact the combustion chamber should work as a mixer of fuel and oxidiser, and therefore needs some containment especially when one of them is heavy (EtOH or RP-1), the mixture is afterwards injected into the nozzle where the effective combustion takes place propelling the rocket. The expanding gases pushing against the parabolic walls in all directions: in the forward direction create a net push. expanding gases that push side wards produce no net push as they cancel each other's. and the backwards moving gases are, bounced parallel outwards reducing drag. Notice how the most powerful rocket engines like F-1 have a huge parabolic-like nozzle, compared to the combustion chamber. Good luck
That design never made sense. You must contol flow of each fuel channel by avoiding bottlenecks. The hydraulic pressure in a 360 degree open mantle never made sense.
First! Also, I did not need to study physics to tell temperature from heat, that's mid-level physics curriculum. One question, are you still doing the spiral guide wire thing that you falsely assumed would improve cooling (ua-cam.com/video/tlqAS6MwkNw/v-deo.html)?
People falsely assume that "heat capacity" is like a bucket that can be filled at any speed until full when in fact it fills slower the closer to "full" it becomes, and also that flow speed, rather than flow rate, is what improves cooling. I elaborated more in a comment on that linked video. Please follow the link to the video via the video link which I used to link to the video.
Alright, copied and pasted here for you: ua-cam.com/video/tlqAS6MwkNw/v-deo.html - And that makes absolutely no sense. At all. That is like saying filling a garden hose from a tap is faster than filling a bucket from a tap, even when both "containers" have the same volume. Making the fuel channels longer while keeping the jacket volume the same does not make the fuel spend more time cooling the engine. It will simply flow faster to cover the now longer distance. Higher flow speed (as in, surface covered over time) does not do anything when it is effectively still the same flow rate (as in, total amount passed through over time). X amount of coolant can only take Y amount of heat energy for Z of a given delta-T. (Ignoring phase change here which you don't want anyway. Cavitation is a bitch.) Rather than gaining better cooling, you're only making life more difficult for yourself: 1) More complicated assembly due to the need of keeping the bloody wire spiralled, 2) heavier engines and greater material cost due to more material added, 3) lower feed due to higher flow resistance that must be compensated appropriately, and 4) believe it or not, the spin imparted on the fuel will result in a small rolling momentum (although most will be negated since it's more or less a closed system) that can irritate the eff out of you trying to eliminate if you didn't know where it was coming from. So, please don't do that.
It's people like you who inspire me to pursue engineering, thank you Copenhagen Suborbitals!
Thank you CopSub. I've been toiling for a while over a solid-fuel engine design involving sodium bicarbonate, and constructing the reaction chamber has been one of the most challenging things for me. This video actually revealed to me the physics behind the reaction chamber, and now I feel like a huge weight has been taken off me. Thank you once again, and good luck to Spica!
lol he said that when building rockets 95% of the time is spent beating your head against the wall. only 95%? im ready for it!!
Gr8. Now get ready for 99.999995%
@@aniksamiurrahman6365 That's it, I'm in
Thank you so much for your kind explanation and your are been absolutely amazing and fantastic and wishing you a success in your next rocket engine design
You're welcome, thank you for following us!
Really really appreciate this video, your project, and how hard you folks work to communicate about your effort and rocketry generally. Wish all of you on the Copenhagen Suborbitals team the very best of luck.
I suggest looking at the German A-4 (V-2) rocket motor. It used several smaller Injectors to achieve reliable combustion. Good work.
Very good video...I like how he kept it simple for the layperson....by the way the licking your finger on the hot plate reference to the fuel spray inside the engine is called latent heat....it's a physics property of liquid changing state and the heat it absorbs..
Very knowledgeable. Thank you
You're welcome! We have way more in depth rocket content around building them, if you are interested.
Thank you for sharing! You really inspire and help others to keep interested and helping. I love the expression that "rocket development is 95% banging your head with the wall and 5% success". Learning from mistakes is what lately make the success. Thanks and keep going!
Where did you get the fuels and oxidizers from and how much did they cost?
How do you manufacture the shape of the nozzle?
Thank you so much for this explanation! You have simplified the subject matter and now I understand the cooling process. I wish you success and hope you can launch Spica soon!
I love this video I showed it to my nephew he understands them better now.
Thanks
How cleaver,the fuel itself works as a heat exchanger ❤
Thanks for sharing MADS!
awesome, really clear explanation, love what you all are doing, very inspiring!
Good to see that You guys are still up and running those projects!
I must say that I am realy excited to follow this!
Very good lesson my teacher.
Nicely explained
Great video!.....why is your combustion chamber so big (long)?...What governs the size of a rocket engine combustion chamber?
You can find more info here for example: www.braeunig.us/space/propuls.htm
Great video, im just curious how the high presure exhaust is controlled from going up and out the way the fuel came in? Since the presure is so high does that mean that the amount of presure the fuel is injected is higher thus preventing the exhaust re-entering the fuel pumps? Best regards
You're exactly right, feed and injector pressure is always higher than the combustion chamber pressure.
@@CopenhagenSuborbitals Thank you for the answer :)
Thank You so Much Sir 👍👍👍
Thank you so much for sharing! It inspires me as a undergraduate mechanical engineer student. Hope I can support one day. Keep going. Amazing content!
Thank you 👍 very good
Thank you! :)
What is the desired pressure in the nozzle? It low pressure / high expansion is more efficient, right? Never thought about that the nozzle has to withstand those high pressure levels so it doesn't implode. Very interesting!
There's really no general answer to that - it depends on the engines geometri, fuel types ect. And expansion also depends on ambient pressure a a given altitude. That's why second stage engines always have this huge engine bell :)
you guys are heros
how do you make a anti backflow valve in your pipe?
What metal is this combustion chamber made of? Is it regular steel?
Have you ever thought about cooling the engine by brazing copper pipes on the inside of your combustion chamber? I mean obviously it would take a lot of man hours to do so, and very precise work to achieve repeatable results, but it would keep the engine cooler and might solve a few of the problems.
Surely you mean outside
Wow this video is really instructive very well explained, thank you!
99% perspiration and 1% inspiration :-)
One question. I understand that Spica is a star in the Virgo constellation, but why did you choose "Spica" for the name? Thanks!
We had a vote within the organization :-)
Sir which fuel is used in rocket
Please sir tell me about that
We use ethanol and liquid oxygen.
Thank you sir
which is the better or 2.0 engine u guys made?
are you going to use the bpm-5/-design in a rocket/vehicle that will pass the karman like? like using the basic engine clustered or with a big engine bell in vacuum?
Not likely - we are working on a 100KN+ engine for the Spica class rockets
I think they need a small engine bell to be efficient in their case. It is after all a suborbital flight.
A two stage rocket with a 9-cluster of BPM-5's could potentially launch small sattelites to orbit!
if i had a mod for ksp, i would have done it.
I was wondering why you don’t use a LOX fuel system instead of ethanol is there something more favourable about ethanol or is it just production?
We prefet to use LOX as our oxidizer that it is. :)
Have you ever thought about using liquid hydrogen or kerosene?
@@jackrigby6678 Hydrogen is extremely hard to work with and kerosene is not a very environmentally friendly option when we are launching rockets from the sea and risk large amounts of it being dumped into open waters.
Thank you for taking time out of your way to reply, good luck with the spica rocket!
@@jackrigby6678 You're welcome and thank you!
what is the purpose of those pipes coming out of the side of the cooling jacket?
I suppose that they feed the rocket wall jacket with cool fuel. They propably have multiple mounting point to cool the wall faster. If they fed fuel from bottom upward at a single point that could cause bad cooling distribution.
So it wasn't just bad welding of the nozzle as first reported? Old Boost made a design error too.
Would be good to have more structure data about it.
How the built was approached, how to do the math, simulations, issues, and so one. A step by step tutorial with a knowledge center, so people across the world could self educate, replicate the rocket, and contribute.
Thanks.
Superb video bro
the fuel that runs by the sides is pumped or uses vaccum?
Pressure fed straight from the pressurised propellant tanks.
isn't there any ignitor used to start the combustion?
So far we've used a pyrotechnic igniter suspended inside the combustion chamber to ignite our rocket engines. You can see it flying out at 5:07
Copenhagen Suborbitals isn’t that just basically a giant match in the engine to start it?
You are very crazy but it's so fun !! Good job guys !
We take that as a compliment - we aim to inspire!
#lovespace
Crazy?
This was insightful. Thanks
Great video.
Is it possible to make a small working model of this engine at home... I have access to liquid oxygen and ethanol /methanol
You’d have to figure out how to pump it hard and fast enough. That basically requires turbo machinery of the highest degree or a really powerful electric motor (in the case of Rocket Lab’s Electron rocket)
BrokenLifeCycle RocketLab is using brush less DC motors which are easily available and turbo pump can be made from car engine turbo pumps
Dollar Projects if you have a cnc or a 3D printer you can easily make an impeller that is power as required. The rocket is 60% plumbing (combustion cycle), 20% nozzle, 15% cooling, and only 5 percent everything else.
Makar Lock Thanks for the help :)
Small liquid rocket engines use high tank pressures from a secondary Nitrogen tank to generate the required fuel flow. If you're looking to build a really small engine, I would recommend reading www.cientificosaficionados.com/libros/cohetes.pdf
If I had any mechanical knowledge I would absolutely build one myself. Alas, I work with computers instead.
Now please teach us how to build such an engine.
and for the next class, how to build an ICBM
You literally just need to go to another video and we show you that (the engine, that is). :)
ua-cam.com/video/n8_6SwQXYgs/v-deo.html
❤
I learnt a lot of things thanks to your video ! Keep doing that because it's amazing
Hi, it seems the throat is too wide and the nozzle too narrow and short. The mixture is ejected too soon out of the chamber and nozzle, and the combustion takes place too far away from the engine. In fact the combustion chamber should work as a mixer of fuel and oxidiser, and therefore needs some containment especially when one of them is heavy (EtOH or RP-1), the mixture is afterwards injected into the nozzle where the effective combustion takes place propelling the rocket.
The expanding gases pushing against the parabolic walls in all directions:
in the forward direction create a net push.
expanding gases that push side wards produce no net push as they cancel each other's.
and the backwards moving gases are, bounced parallel outwards reducing drag.
Notice how the most powerful rocket engines like F-1 have a huge parabolic-like nozzle, compared to the combustion chamber.
Good luck
Permettez a votre communauté d'écrire des sous titres, c'est possible ? Sa me permettrais de comprendre vos vidéos ^^
That setting is enabled so feel free to add french subtitles :) Actually we need a french translator for subtitles on all our videos.
I can translate a few!
can you start with this one ? :)
Copenhagen Suborbitals that's could be awsome !
👍
u look like Tony stark sir
the moment i heard the german accent i knew he was legit
That design never made sense. You must contol flow of each fuel channel by avoiding bottlenecks. The hydraulic pressure in a 360 degree open mantle never made sense.
So this rocket runs on hand sanitizer???!!!
so pity
You didn't explain how rocket engine works. But you did great job because
You just explained how your stupid desogn failed
Hindi make you video
First! Also, I did not need to study physics to tell temperature from heat, that's mid-level physics curriculum.
One question, are you still doing the spiral guide wire thing that you falsely assumed would improve cooling (ua-cam.com/video/tlqAS6MwkNw/v-deo.html)?
Hi Anvilshock - the design of the Spica engine will be a lot different from the BPM5 design.
Best of success! Still, the jacket machining used for the BPM5 looks so mesmerising and cost-effective, I should hope it becomes a success, too!
The BPM5 works great! The original one has been fired over 30 times and still going strong.
People falsely assume that "heat capacity" is like a bucket that can be filled at any speed until full when in fact it fills slower the closer to "full" it becomes, and also that flow speed, rather than flow rate, is what improves cooling. I elaborated more in a comment on that linked video. Please follow the link to the video via the video link which I used to link to the video.
Alright, copied and pasted here for you: ua-cam.com/video/tlqAS6MwkNw/v-deo.html - And that makes absolutely no sense. At all. That is like saying filling a garden hose from a tap is faster than filling a bucket from a tap, even when both "containers" have the same volume.
Making the fuel channels longer while keeping the jacket volume the same does not make the fuel spend more time cooling the engine. It will simply flow faster to cover the now longer distance. Higher flow speed (as in, surface covered over time) does not do anything when it is effectively still the same flow rate (as in, total amount passed through over time). X amount of coolant can only take Y amount of heat energy for Z of a given delta-T. (Ignoring phase change here which you don't want anyway. Cavitation is a bitch.) Rather than gaining better cooling, you're only making life more difficult for yourself: 1) More complicated assembly due to the need of keeping the bloody wire spiralled, 2) heavier engines and greater material cost due to more material added, 3) lower feed due to higher flow resistance that must be compensated appropriately, and 4) believe it or not, the spin imparted on the fuel will result in a small rolling momentum (although most will be negated since it's more or less a closed system) that can irritate the eff out of you trying to eliminate if you didn't know where it was coming from. So, please don't do that.
Man......this is rocket science looking easy....but not.