Liquid Rocket Engines 2: Injector Trades 

Thank you for the feature and keep up the good work! :) Best from Copenhagen!

When Charlie said notes, I was expecting a confusing pile of pdfs. So organized and easily accessible! We really need to thank Charlie for his efforts he puts intk this!

new favorite channel? could be. I have never supported anyone on patreon before, but this is a project I could get behind if you share all the cad files, research, plans, and code

I’m an Aerospace Engineering student in California and I’m currently in Denver for the summer to design a rocket engine too!!! I think it’s so cool to see your design process and logic. Keep posting these videos man!

Theres been a lack of exactly this type of educational content. Thank you!

When you have to limit your homemade RU-vid presentation by disclaiming ITAR, not having funds for the engine parts of your choice is definitely a temporary condition. Keep going. Change the world.

This is a really great series. Thanks for spending time on so much of the details!

This channel is fantastic. You touch on all the little esoteric details that other channels gloss over for the sake of a larger subscriber base. If the average man likes rocket engines, they watch Scott Manley or Tim the Everyday Astronaut (great channels in their own right). However, a true rocket engine lover watches Charlie Garcia. Fact.

Charlie I'm watching this in Oct. 2021. So your efforts two years ago are still educating people. Thanks so much.

I was with you until the math, started swimming abit then after watching some more I think I'm with you again. To be young again and to not have to try and recall all that math I had just learned in school.....lol see what 30 years of cooking will do to you. Wanted to be a mechinceist out of school but well cook took over. Long story nobody want to hear.......lol great video been a while since I've had to think analytically. Thanks so much for that keep up the great work!

I Take away All your aweosme Rockets... ITAR

Wow I have a big interest in injector designs and always wanted to see how they react in real life. How you 3d printed models of them and sprayed water through them is ingenious Charlie! So cool to see their flow characteristics!

Dude THANK YOU! I have been looking for something technical and somewhat in depth. I think this is the only videos like this. Hope to see you working at space X one day

Liked the video without having watched a second of it (oh and first by the way)

I have been hungrily learning about cooling methods and convective heat transfer for about 12 hours now, beginning to feel unstoppable when I stumbled on to this video and well Charlie you managed to finally overstimulate my brain and now I am going to sleep. Thank you kind sir for your wonderful knowledge and please don't blow up your pintle with that low pressure drop good luck lord Charlie.

You've touched on a number of subjects that I have wondered about but had no way to grapple with. Thank you.

Its nice that we can find this information online and its public domain

Your a very smart man. I only wish more people would listen to people like you :)

Great video Charlie. Love the B-roll of the injectors demonstrating the different flows. Can’t wait for next one.

If only you and Scott Manley could talk on a live stream about more engine ideas, that'd be cool I just found your channel and I love your videos!

Start a patreon page, that would help you to cut the costs

I was just wondering when the next video would come out, thanks!

Wow!... this guy is a genius.

Yes ! One more rocket guy :) The DIY rocket that we can build easily ourselves is coming closer and closer. Keep working and posting !

This is insane! I want to build one! I have so much to learn!

Thnx sooo muh for this kind of a video , it's really rare to see such a good video on rocketry on tt 🙂🙂

I promise , the notes linked are soo good and helpful

I’m complete amateur to anything engineering let alone rocketry. I’m attempting to build my own rocket that I hope eventually will lead to a flyable rocket. Your videos seem like a great start so thankyou

Have been trying to design some rocket engines myself, after months of hard work, hoping to find a teacher... Well, why didn't I look into youtube. At least i'm smart enough to find the CEA program that does the maths for me. Currently still figuring out stuff about the injectors, extremely helpful here.

great video! hope you keep doing more of these!

This is great. Thank you.

That was so cool. Cant wait for the next episode !

4:52 aaah that laminar flow

5:22 What 3d printer and filament did/do you use for your examples? Also, I appreciate the time you put into this content, Thank you

Great video Charlie, very helpful!

Great work! My new favourite channel as well.

I feel like with a lathe you should be able to hit quite tight tolerances (around 0.05mm) on simple features, even if that means finishing with emery cloth.

congratulatins for these excellent explanations.

Hey man, great video! I would love it if I can get the stls of some of the injectors! Our team is trying to design and machine an injector for a somewhat large hybrid rocket engine for the first time!

Charlie briefly touched on one fact that few people realize: things do NOT burn, until they are in a gassious form! Look closely at any solid object that is 'burning' (wood), and you will see that it is the vapors coming out of the heated wood, that burns, and the heat from that combustion makes the wood release more vapor. Same thing for liquid fuels - burning takes place at the interface where the liquid is turning to a gas. The liquid itself does NOT burn. That is the secret of why today's vehicles have better fuel mileage than those of 40 years ago - better transformation of the gasoline fuel to a gas for combustion. Example: Charles Pogue's 1938 carburetor that achieved 208 mpg that was certified by the Ford Motor Company which recorded 27 miles on one pint of gasoline (216 mpg). That is also true of SpaceX's Raptor engine and Blue Origine's BE-4 engine. Their efficiency is in part due to using fuel and oxidizer that are both normally gassious before combustion.

Can you talk a little more about the cruciform? Looking good Charlie, keep going.

I am not sure what sort of machining facilities/equipment you have access to, but if you have a mill and vertical rotary indexer (i.e. the axis of rotation is parallel the ground) there is a way you could machine a vain-less pintle element (i.e. to provide a smooth curtain of oxidizer rather than radial jets). Basically it would be to come mount the "blank", as you call it, in the index, and com at it from the side with an end mill of the appropriate diameter. Once you reach the necessary depth of cut, begin turning the index slowly (make sure to keep in mind which direction is climb milling vs conventional milling) until you do a full revolution. Presto, smooth pintle element.

you can use two different colors to see how well your injectors are working (water).

I was in the military defense business some years ago ,now I am very interested in developing missiles for a new type of combat vehicle. I am going look you up in a couple years Charlie,to help us with a new type of missile. Great job young man!

I see a Spaceport America Cup patch on that wall!!! NICE! Any updates on the solid propellant simulation software? Waiting patiently..... lol

Hey Charlie, will you make a video about your custom vavles on your RCS system? Even if they leak, it's super cool!

It's Q=V*A not V=A*Q

Going with the lowest pressure drop possible may not be the best idea due to combustion instability. Huzel and Huang (arc.aiaa.org/doi/book/10.2514/4.866197) recommend around a 20% of chamber pressure drop across the injector elements as chamber pressure fluctuations of around 5% are typical. A higher injector pressure drop will lead to a more stable injector as Pc fluctuations will have less of an effect on local mass flow rates.

Really good video. More graphics !

If you study chemistry of different oxidizing agents, your not stuck with Liquid oxygen gas or nitrous Oxide. White fuming acid (WFNA) is a storable liquid oxidizer used with kerosene and hydrazine rocket fuel. It consists of nearly pure nitric acid (HNO3). ... WFNA also as well as RED fuming Nitric Acid is a great oxidizer. Another good oxidizer is Hydrogen peroxide--, Hydrogen peroxide can easily break down, or decompose, into water and oxygen by breaking up into two very reactive parts - either 2OHs or an H and HO2: If there are no other molecules to react with, the parts will form water and oxygen gas as these are more stable than the original molecule, H2O2. You can build a very powerful rocket with this compound called a H2o2 Monopropellant Rocket. Works in the principal of pressurizing 90% H202 with nitrogen shooting into a Catalyst pack that decomposes it into steam and Oxygen which then exits through the combustion chamber with a solid type fuel, and is ignited burning the two substances violently into the conversion zone of the rocket nozzle at subsonic speeds entering through the throat and passing through the diversion zone at supersonic speeds. This is the cheapest and yet most effective way to build a very powerful rocket and it can be throttled up or down. No complex machining is required to accomplish this rocket. Im building a land speed Rocket powered motorcycle so ive been studding a lot. and it helps having a father who works for NASA. Dad get me some Liquid Oxygen and Liquid hydrogen from work LOL

Awesome videos☺ I love them thanks

Plz keep us updated

I have a couple of aluminum scuba tanks sitting in my garage if you're interested!

Very interesting!

Can you make a video on solid rocket booster seperation mechanism? How the explosive bolt works ?It would highly appreciated if you do such one .

Awesome man!!!👊

Hi brother, please excuse my ignorance but I just got curious. Did oscillations on the supply chanel affect rocket's performance? I mean at 4.33 the hose( which supplies water) clearly oscillating, how does a rocket engine responds those type of oscillations? By the way great video. I learnd a lot. Thank you for your effort :)

Hi Charlie, could you please explain a bit on how the fuel and oxidizer flow from the injector plate to the injectors? I am a little confused on the things things that go inside the plate and how the fuel/oxidizer are spread to different injectors through one tube. Thanks!

Charlie, great video! I love it. In the case of an electro pumpfed engine how could do you test how close to flight ready it is or its TRL? I am asking because I was pitched to invest and would like to know how advanced the engine really is. And what parameters are the most important? I imagine chamber pressure(bar/psi), stability, burn time, Isp, etc.

I don't understand why you use the density values ​​for an atmospheric pressure, when the pressure is higher in the engine, to calculate the propellant flow.

Great and informative video. Also, first like

I see you before in BPS.Space

Good video Thank You!

Hi, have you in any part of this playlist mentioned the cost for this entire project?

Hey ,I'm a keen viewer of your videos .Can you please deliver a detail lecture on explosive bolt mechanism ?What mechanisms are used in solid rocket booster seperation ?Please give me a reply

Hello, I am currently a senior in university studying Aerospace Engineering. I am working on a senior project to design an aerospike, both liquid and solid fuel. Currently working on designing an injector and combustion chamber for the liquid aerospike. I would like to present to my team some options for the injectors and would like to 3d print them. Could you send the stl files my way? Would be greatly appreciated. Thank you

This is so incredibly cool! The only thing I’d ask is that you talk just a little slower haha, but maybe that’s just me

Very neat videos, only problem is I have old ears. When you are describing your designs you sound just like the air traffic controllers at DFW, I had to get them to slow down the speech. Good thing I no longer look out the front window of jets. Please keep the good work up, even us old engineers like new fresh minds and old minds can still learn, I hope.

I'm building a solid fuel rocket. I apologize for my ignorance here. I want to make a liquid rocket engine, but how much pressure is enough to pump the fuel into the combustion chamber. Or I have no idea how to do that. I don't know if I can complete the rocket with this and I'm going back to this video for fuel injectors.

Are you getting paid for these videos? They're so good man!

Hello, Do you think it would make sense to make a fog machine using the same concept as rocket engines use to vaporize a liquid? If you could respond that would be awesome. Have a great day.

Question: Is the injector for a LASR engine very different to that of a "conventional" rocket engine?

Consider CFD software to check your flow geometry calculations.

So I’m just a little confused so you have both a oxidizer injector and fuel injector like so separate injectors I’m assuming so but just making sure

Quick question: What are the legalities of building a liquid fueled rocket engine?

Idk if you are still reading these comments but if so can you link the 3d files of the different types of injectors? And thank you for these videos these are very helpfull and interesting!

Maybe this is a stupid question but, why not just car fuel injectors?

I'm designing a liquid rocket engine with a coaxial swirl injector. Are there any handbooks or guides on designing and doing the math on those types of injectors? I'm sure there are some long research papers that would take a while to find and to read through.

I'm not exactly an educator, but I was wondering if I could get those stl files so that I can use at a prototype injector that I have to design for my trainee project at my university's rocket team. Thanks in advance for the attention

why the bipropelent engine dont get mixed befor combustion? oxigen if got flame inside will blowup and the methane the same(or i am worng). So mixig them before chamber to avoid injectors(using just valve)

Hey Charlie. Great video. I’m currently in school for aerospace engineering, and am trying to do some research (and building) of a small scale rocket. Long term goal is to launch a small payload to about 10,000 feet (could change to 30,000 ft). Any advice or help you could offer me would be greatly appreciated.

You keep going, i have an icbm I have to make (for legal reasons that's a joke, America)

How do you calculate actual pressure drop across injector ? How did you get lower end of acceptable pressure drop ?

Hi Charlie, thanks so much for your videos! I've been designing a rocket for about a year now, however I've struggled with the oxidiser. I was wondering how you were able to source your liquid oxygen?

Pfftt.... ITAR. In all seriousness though, I'm half contemplating building a small rocket engine for a personal challenge, even if it's the shoddiest, silliest thing. Also, if a catalogue part works for your project, I'd just call that resourcefulness rather than something to be "not proud of." IDK, I need to figure out how to get into engineering. I'm realizing it's my true love. I studied physics, but I have an immense need to design functional things, and that you just don't get to do in physics. Also have ADHD which was undiagnosed, and got crappy grades, so, I need to chart my path. At least I know what I love now.

How do I go about the design of a pintle injector for ethanol and gas oxygen

Can I get the 3d model of the pintel injector so that I can 3d print it? Sry to ask this cause we are a bunch of school students who need to do this..

Can you explain the pintel injector in more detail?

Have you thought of using Butanol Alcohol? It creates slightly cooler tmperatires than Kerosene does. And it has smaller combustion-instability (oxygen atom in the molecule), problems.

what pressurant is used for the tanks (Helium?) and how are they put into the tanks?

Do you know any other way propellant mixture ratio can be controlled without control valves?

Do a series about gas rocket engines (It might only help for me to make games)

Do you use high pressure He to flow your fuel and oxidizer?

Hello charlie, I need the stl files for the injector for my classroom demonstration as i am a teacher at aerospace research institute. Dont know if you are responding or not.

What if I take the liquid oxygen oxidizer and mix it with kerosene as propellant and store it inside the same fuel container with the right proportion of each? And use a car fuel injector to atomize the whole mixture and inject it into the combustion chamber?

hey charlie i would love to have the stl files to demonstrate thanks, Luis Walsh

Hi Charlie, when someone is almost done with his own ICBM, do you know where it can be internationally offered? I think it may be of the interest of some Asian or Middle East country, I have a great Business Model and I have crafted a great pitch in case you know an investor with some free time. BTW, Alibaba and Amazon are not accepting shop petitions to sell ICMBs, something about arms, deaths and human rights that it is several pages long. In case the NSA is reading this, I am writing this for a friend. Thanks in advance!

I heard that bps is working o an engine are u both working on the same engine?

You sir are a God thanks for all of this 💯💯

Cool videos dude! You talk a bit fast though