Liquid Rocket Engines 7: Tanks and Capacitors

Hi Rocketeers!
Today we're talking about the tanks and test stand mechanical design from my new workshop in beautiful Colorado.

[CopenhagenSuborbitals]

Why is everyone making videos on propellant tanks this week?? Including us!

[CanineDefenseTechnologies]

I think it's pretty ingenious to use beer kegs. I always thought looking for parts from a different field with the same specs that cost far less for rocketry would be great, and this is a great example!

[OrionAerospace]

Keg tanks and the engine is running on ethanol 🤔 I sense a theme

Great video man! You’re presentation skills have dramatically improved and your personality is coming across real well! Can’t wait for more

[maxhaynes]

Welcome to Colorado! Should come out and visit the northern Colorado rocketry club, been flying with them for over 7 years

[jborgesss]

Thanks for the video Charlie. The beer keg idea is very interesting!

[Thorgon-Cross]

For my first bi-prop engine (was only few N) I used a old chemical fire extinguisher, the type that hang on the wall. For the 5Kn engine that I have been working on I was planning on using a stainless steel water fire extinguisher, they are rated to the 300 psi, that I am planning on using, also are hydro tested to 500 psi. I like the idea of beer keg as it will allow me to have a longer burn time.

[whcolours]

Y'all ever feel bad for wasting a small amount of this lad's time on Twitter, while also having a vine play through your head once you heard "Giraffe"? Just me? OK

Anyway, fantastic series so far! This'll be plenty useful for amateurs like myself!

[Heikakyu]

Charlie is getting more confortable with the camera, I guess that's one side effect from 'Cooking with JoeyB'

[SurfyKirky]

Been great watching your videos, I hope you make an open source schematic. I’m learning a lot from watch yours and others videos but it’s so bloody hard to have the knowledge of how to do this. Keep up the great work!

[joeshmoe]

googled rocket fuel injectors, so cool Garcia. We got to get you some more views!

[Starman]

Charlie is just getting stud day by day🤣🤣🤣🤣

[Felipx]

Hey!
Very nice to see the progress that you have made, Congrats!!!
May you explain a little bit better the capilar tube and the capacitor thing ??

Do you know any article that approaches this information / or any source where i can learn a bit more?

Thank you very much for the video 👍👍

[DeadEagle]

Charlie, not sure if you know but imagine you do... cryogenic service valves usually have a stem extension to move the packing material out of the cold area. Not sure from your models if you have that, or if you really have any significant concern with packing damage with this application.

[agsystems]

Great work as always. Guessing you meant 8mm for the steel, and you are not attaching it to the side of a battleship... :P Anyway, only slight modification I might suggest is switching which fitting goes through the plate, so that if the engine goes RUD there is a steel plate between it and the 1.2 safety factor pressure vessels. Or is that deliberate? This way you can put the steel plate between yourself and both the engine and the tanks, and have it double up as your primary blast shield?

Also, are you using helium as your pressurant? I guess it will avoid any possible mixture woes but will probably end up being vastly more expensive than the fuels. An alternative would be have separate pressure tanks for fuel and oxidiser, and use oxygen gas to pressurise the oxidiser and nitrogen for the fuel, (or live dangerously and use oxygen for both, pre-cooling the fuel is suggested if you do this, and not having neighbours. Or ignore any mixture issues and use nitrogen for both. I really don't know if mixture problems would occur). Putting some liquid oxygen/nitrogen in a pressure vessel and then letting it return to ambient temperature (with a regulator, and maybe a little artificial heating for speed). Will need a little more time to set up, but it can actually avoid any fittings that have to be connected under pressure. This can also avoid a large inventory of pressurised gas if you want to do lots of firings without having to resupply, as everything can be easily stored unpressurised.

[robertsteinbeiss]

If you say cryo, think of Insulation and leave some space on the test stand to wrap it around @Charlie

[arielhiramgomezlopez]

Hi charlie, super itneresting video. I was wondering what program are you using for the flow diagram you show in 4:55, it would nice know that.
Very nice series btw, waiting for the next videos!

[thecros]

Hie bro rather than having capacitive lox sensor and its other complexities you can just have them mounted on load cells and then measure weight and get your tank filled volumes.

[TheRealReidMeister]

Hey Charlie, I've been following for a while now and I am actually attempting a liquid engine design in university for an extracurricular group (I'm a junior year mechanical engineering student). So far the most difficult thing from a design standpoint has been the plumbing/valves (especially valves that have to operate at high pressures and handle cryogenic fluids). Do you have any recommendations for textbooks on plumbing (especially plumbing for cryogenic fluids), and also what software are you using to sketch up your plumbing design? In terms of tanks, a roadblock that I've run into that it seems you did too was how to get these tanks manufactured. Still working on that one (and trying to keep the cost down).


Thanks for all of the useful information

[putteslaintxtbks]

I'm rewatching this and again see this set-up looking good for a test stand, but not a rocket as the tanks are side by side were one should be above the other and one tank should be doubled if fuel to ox is 1:2 ratio. Or is this going to be a really fat rocket and maybe a 1:1 ratio with extra fuel for cooling or ?

[jurajkolesar]

Greetings, I have been wondering, what are those fittings that are connected at the keg throat. I have never seen anything like that. It looks very cool.