Liquid Rocket Engines 4: Test Stand

Hi Rocketeers!
Sorry for the late video, I made it a little longer to make it up to you! The plan for this week changed late as I switched towards the test stand, which still isn't done, but I made some good progress.
I still need to plan all of the fuel F/D and engine supply plumbing, and select a relief valve, and design the main propellant valves, which will get their own video. I'm not too far away from making hardware though, my plan is to demo the main valves in the video I design them in with a water flow test, and then continue with engine work as I save up for the regulators
Links:
Patreon: / charliegarcia
SpacePilot Pro (Affiliate Link): www.amazon.com/gp/product/B00...

[@BPSspace]

That intro is 🔥🔥🔥

[@YukonK9]

Rocket science: 99% thinking and solving everything that can and will go wrong. 1% the actual fun stuff. Launching and firing!

[@faizanjanjua5397]

Yukon jokes on you, any engineer will tell you that the 99% of thinking and solving problems IS the fun part ;)

[@YukonK9]

@@faizanjanjua5397 Subjective, but I see your view. I mostly get a bit frustrated with Canine Rocket Tech projects when I'm so close to being done and all these issues arrise delaging launch. Solving a problem after it launched is fun, but solving to get it to launch can sometime be draining. At least for me

[@david_lu]

"The relief valve will protect my equipment in case something impolite happens on the test stand". This series is awesome. I love it! Keep up the good work!

[@chasethevioletsun9996]

That was a very John Drury Clark phrasing. :)

[@michaelgarza9039]

It’s nice to see a actually educated KZbin channel

[@OrionAerospace]

test stands are so cool, but never get the street cred they deserve! great video!

[@YukonK9]

Agreed. Test stands are pretty tricky. I'm finishing up on launchpad and will move up to the test stand. Ton of work involved!

[@honeydew5022]

DH Yukon I see you everywhere and you should totally document your progress on KZbin

[@YukonK9]

@@honeydew5022 Yes I do on Canine Rocket Technologies. It's a open source rocketry company I guess. Because I'm a one man team, it takes a bit to get videos out

[@honeydew5022]

Dogs and rockets... Great combo!

[@YukonK9]

@@honeydew5022 Thanks!

[@rickyerrera6762]

Really loving these vids, im about to start my AE degree and this just makes me so excited!

[@shellhero159]

Same

[@mariohernandez1111]

I would suggest captioning the names of specific parts in the video, and probably add reference images of the component in question. It's pretty hard to understand when you are not sure if you didn't know the terminology, or it's just that you didn't hear it. Otherwise, keep up with the good work! It's not often that we get a detailed series on complex rocketry topics like this one.

[@theelectricwalrus]

FYI, you can slow down the playback speed to 0.5x or 0.75x if that helps.

[@mariohernandez1111]

@@theelectricwalrus That doesn't help when you literally don't understand what's been said.

[@storminmormin14]

“Less safe is different from unsafe”

[@chancepricee]

Love the video Charlie! Keep up the good work!

[@trcxsa]

Your video series has been absolutely amazing so far! Keep up the great work!

[@shanebluebutterfly]

This channel is a resume by itself. Great work

[@theophrastusbombastus8019]

I'm a little envious of the disparity in knowledge you have over me even though we are more or less at a comparable academic seniority but also incredibly thankful for your dedication to share your work so that I can learn as much as I can. Really, thank you!

[@lewispowell1681]

just finished 1st year and so glad i found your channel. My friends and I are starting a rocketry society with the end goal being a liquid fueled engine so this is just the ticket to get inspiration thanks subbed

[@polakjan]

Hi, thanks for a really interesting series. It's great to see people that have the chance to pursue a hobby like this, and even better when they share it with others. I have just a single suggestion regarding the video quality. When making a cut add a bit of delay before you start talking again, the way you do it right now sounds quite unnatural, though it's probably not a huge deal for most people. And thanks again :)

[@addisonmartin730]

I love the new intro!

[@bethaniericci6201]

The project management comment….I almost cried.

[@GG-wm6kl]

Keep up the great work!

[@WeBeGood06]

Nice test stand.

[@franteryda4730]

Love it!

[@pitu72ger]

Keep it up!

[@NielsNL68]

Hi Charlie, may i ask you to slow down your talking, i love to watch your video but man you speak fast. I'm not a native English speaker so i need to translate in my head what you say. Thanks man most appreciated, i love to see more from you,

[@austinskylines]

Niels vd Spek change the speed on KZbin?

[@animationspace8550]

@@austinskylines Then it sounds funny

[@jackdavies5784]

What software do you use for the pid drawings?

[@PauloDutra]

Amazing channel ! Make more videos pls :)

[@mullendaisaac9516]

Nice video ! What software do you use to represent your system ?

[@cantsolvesudokus]

Don’t know if fire is still a risk if the whole container is purged with nitrogen, but I’d think some kind of fire extinguishers mounted to the structure wouldn’t be a bad idea. Really enjoying the whole build process and wishing you good luck with things :)

[@Spy653]

Might be covered later but, I'd suggest adding battery power monitoring system, incase you get a dodgy cell, so that it will not fire without X% battery (assuming you're not using mains or a generator for power).

[@ben1techie]

You should do a collaborative video with this old tony

[@thecros1076]

Can you please tell me why nitrogen purging is used and how it can be useful for not forming frost on the valves? Please I need this answer do let me know please 🙏

[@t_c5266]

You don't have a PT/gauge post reg between the reg and the valve? I'd definitely include one just in case whatever you have on the reg is faulty. So you don't just juice your tank to the wrong psi.

[@spacedoge3508]

so are the fuel tanks scuba tanks with extra holes on the bottom side?

[@TheKerbalKing]

Do you plan on putting this in a rocket eventually?

[@mdansar8881]

What about the propellent tanks?

[@nicholas1327]

Are you planning to put this engine on a rocket

[@AstroCharlie]

Well, it has to work first. If it does... who knows what the future holds?

[@aurorajunior6328]

where did you get the COPV

[@benniehill927]

Are there any resources you have on the plumbing aspect of the rocket?

[@flograuper9294]

Im fine with you talking fast. This way you can pack more information into a video. But when showing stuff, please make a pause so people can look at it without having to pause.

[@bindudiva1448]

what are the parameters required for a rocket engine test designing?

[@ozgurbozkurt5945]

"rapid unscheduled disassembly"

[@agsystems8220]

Looks very solid. The only significant difficulty not addressed is fuel level instrumentation. Do you have a fuelling procedure set up already? I guess that will be gone over (and practiced) for the injector tests, but if your only instrument to infer levels from is the nitrogen tank pressure you need to be able to hit the same initial marks reliably. Is there going to be flow rate instrumentation on the stand or the rocket or both? If this rocket is only going to be on the stand then having instruments on the stand might make sense, especially if you want to build a stand alone engine in future. Having test instrumentation to calibrate flight hardware against could make your life much easier in future. Plus if the engine fails it is less likely to take out the flow rate sensors if they are mounted fairly remotely. Steel plates between the engine and the stand hardware are your friends. You could infer flow rates from valve positions and existing pressure readings, but debugging it might get frustrating if there are problems even if you do get good calibration. Call me old fashioned, but I'd take a direct measurement any day ending in a y.

[@AstroCharlie]

The reason fuel level instrumentation isn't addressed yet is because I'm still deciding between capacitive, mass, or ultrasonic measurements. Flow measurement sensors are not likely to make it into this design, I don't really have the money for venturis or flow measurement devices. I'd love to eventually add some though. There's a really big steel plate already in the design for exactly the purpose you propose. Thanks for the excellent comment!

[@maxk4324]

@@AstroCharlie I'm in uni studying engineering to one day also be a propulsion engineer, and what we do on my student design team is hang our oxidizer tank from a load cell (we make hybrids so we just have the one tank). It works well enough for filling we've found. I've never heard of ultrasonic liquid level sensors, so I'm not sure how they work but I wonder if they pose any cavitation risk to the cryogenic oxygen during filling when it's pressure will be lowest. Anyway, keep up the awesome work!

[@AstroCharlie]

The issue with hanging tanks is that I need enough compliance in my lines to get an accurate measurement, which is challenging with my 1" hardlines. If cavitation occured during fill, it'd be totally fine, although I'll be filling under pressure, so I'm not worried.

[@maxk4324]

@@AstroCharlie oh ok, fair enough. For us we use liquid nitrous so cavitation is a big issue (as gaseous nitrous is easier to get to spontaneously decompose) and capacitive measurement is a hard no since nitrous is not very conductive and can build up large static charges that eventually discharge like sheet lightning, which has been shown to potentially cause runaway decomposition events. However its ability to autogenously pressurize and store safely at room temp is what makes it worth it for us (also we get it sponsored and there's something about not looking a gift horse in the mouth that comes to mind especially when your a bunch of students trying to buy rocket propellants). Regarding hanging tanks, ya I can see hard lines getting in the way with a smaller tank. Ours is rather big so the amount that the hard lines interfere with the measurement is negligible. If I may ask, and on a different note, what sort of thrust are you looking to generate? Also do you plan to regeneratively cool or maybe use a dedicated coolant like water for your first test? Just curious. Looking forward to future updates!

[@agsystems8220]

@@maxk4324 Another potential issue with load cells is that the flow rate is high enough that your outlet produces non negligible thrust, which needs to be corrected for.

[@Saturn596]

Great series. If you happen to have some problems with manufacturing, contact me, I can help with that

[@stocky9218]

Where the hell are you getting LOX

[@orcus7877]

Next time turbopumps! :):) pls

[@AstroCharlie]

It'll be a good while before I design any turbomachinery. I need to get a little smarter and my budget needs to get a little larger.

[@orcus7877]

@@AstroCharlie 👍👍👍

[@alexneff3512]

Second

[@owenconstine6906]

3rd

[@ryan-kw8xf]

5th

[@projectspace7147]

first

[@chechnya]

Dude, chill out with the jump cuts. It's annoying af.