KSP inspired me to design a liquid-fueled rocket engine

[Steel]

2 hours ago, The Raging Sandwich said:

I've actually been designing a rocket engine too (liquid fuel) that runs on Furfuryl and Red Fuming Nitric Acid.

From the wikipedia article:

Main  hazards

Skin and metal corrosion; serious eye damage; toxic (oral, dermal, pulmonary); severe burns

 

and the mandatory John D. Clark recollection from Ignition!:

"the acid couldn't be kept indefinitely in a missile tank — or there wouldn't be any tank left. It had to be loaded just before firing, which meant handling it in the field. This is emphatically not fun. RFNA attacks skin and flesh with the avidity of a school of piranhas. (One drop of it on my arm gave me a scar which I still bear more than fifteen years later.) And when it is poured, it gives off dense clouds of NO2, which is a remarkably toxic gas. A man gets a good breath of it, and coughs a few minutes, and then insists that he's all right. And the next day, walking about, he's just as likely as not to drop dead. So the propellant handlers had to wear protective suits (which are infernally hot and so awkward that they probably cause more accidents than they prevent) and face shields, and frequently gas masks or self-contained breathing apparatus"

 

Not sure it sounds like great fun to me...

[The Raging Sandwich]

Like I said, just a design!

[shynung]

@The Raging Sandwich You should be using IRFNA (inhibited red fuming nitric acid). It had corrosion inhibitor (HF) mixed in to keep it from chewing the tank. Still dangerous otherwise, but it can be stored for quite some time.

Of course, I'd probably go for HTPB+aluminium/HTP hybrid combo. Peroxide is hypergolic, so the engine can throttle pretty far down. It's also great for powering turbopumps and RCS thrusters, in addition to being able to be used for engine regenerative cooling.

[The Raging Sandwich]

3 hours ago, shynung said:

@The Raging Sandwich You should be using IRFNA (inhibited red fuming nitric acid). It had corrosion inhibitor (HF) mixed in to keep it from chewing the tank. Still dangerous otherwise, but it can be stored for quite some time.

Of course, I'd probably go for HTPB+aluminium/HTP hybrid combo. Peroxide is hypergolic, so the engine can throttle pretty far down. It's also great for powering turbopumps and RCS thrusters, in addition to being able to be used for engine regenerative cooling.

Thanks, I'll have to do that!

[wumpus]

On 10/30/2016 at 5:17 AM, shynung said:

@The Raging Sandwich You should be using IRFNA (inhibited red fuming nitric acid). It had corrosion inhibitor (HF) mixed in to keep it from chewing the tank. Still dangerous otherwise, but it can be stored for quite some time.

Of course, I'd probably go for HTPB+aluminium/HTP hybrid combo. Peroxide is hypergolic, so the engine can throttle pretty far down. It's also great for powering turbopumps and RCS thrusters, in addition to being able to be used for engine regenerative cooling.

I remember John Carmack (back when he was working on Armadillo) complaining that HTP was essentially impossible for him to obtain.  I suppose if you can get red fuming nitric acid (inhibited or not), you can probably get HTP, but such things provoke a bit of attention.  After reading Ignition, I'd also expect that most of these older methods are obsolete.

If you can handle LOX, that is probably the ideal oxidizer for high power rockets.  Obviously RP1 is the favorite fuel, but the alcohol (mixed with water to drinkable levels) used in V-2s had almost the same ISP with wildly lower temperatures (something like 1000C less).  The conclusion of Ignition appears that in the end, they couldn't find a mixture that could beat these (although hydrolox obviously wins the ISP race).

Nitrous oxide is also a favorite oxidizer for hobbyists.  It is typically used in hybrid rockets (rubber solids plus liquid oxidizer), but might make a good oxidizer with alcohol (although I'd spend a great deal of time in the library before venturing into the lab for any such mixture).  That the stuff is sufficiently tame to be used in commercial kits for car modification implies it is a whole lot safer than liquid oxygen.

[cantab]

At least in Britain N2O is going to get harder to get hold of, because it's become popular as - actually, as something I'll get a forum infraction for mentioning here.

[wumpus]

On 11/1/2016 at 0:36 PM, cantab said:

At least in Britain N2O is going to get harder to get hold of, because it's become popular as - actually, as something I'll get a forum infraction for mentioning here.

In the US you can obtain N2O relatively easily (for drag racing), but it includes additives to make it less useful as anything but an oxidizer (which wouldn't stop a rocket enthusiast).  My understanding of the typical source used for "other applications" really wouldn't supply the quantity you need while the drag racers' "blue bottle" is likely enough for some pretty big rockets.

[TheEpicSquared]

Is this engine still being developed, @ap0r?  

[ap0r]

2 hours ago, TheEpicSquared said:

Is this engine still being developed, @ap0r?  

Yes, the project is still very much alive! It's just that I have some very complicated real life responsabilities and issues that prevent me from having free time, taking my notes and blueprints and making them into a good quality article. Also i've ran into some legal trouble and I'm pretty broke, so there really is no money to continue the hardware build in these days. But rest assured, this will be completed if it takes me 20 years!

[cantab]

Legal issues with the rocket engine, or with something else? (Or is it confidential?)

[ap0r]

1 hour ago, cantab said:

Legal issues with the rocket engine, or with something else? (Or is it confidential?)

No the rocket. Personal issues, which I'd rather not discuss in a public forum. I hope you can understand.

Edited February 26, 2017 by ap0r
typo

[totalitor]

Back to the business, now it is summer and I can work outside.

I build a fuel feeding system. I use nitrogen as a pressurant gas and 22 mm copperpipe as a fuel tank. I have integrated pressure regulator on nitrogen source, I can get 0-50 bar pressures. I am planning only short burning, up to 10 seconds. Calculated thrust is 8,9 N (2 lb) so I need only 0,02 l fuel to go. I tested system and it did worked well.

But now starts difficult part. Gaseous oxygen. I hoped I could find pressure regulator up to 25 bar, but I have now only 10 bar regulator. So chamber pressure would drop much. If I suppose chamber pressure 8 bar and feeding pressure 10 bar would this be enough?

How about chamber lenght? According my calculations it would be over 30 cm (chamber diameter is only 6,4 mm). With my tools I can not work with too big copper parts (I am brazing parts together). I would like to use large diameter chamber but I can't.

And cooling? Do I need cooling for 10 seconds?

This is very slow - but very interesting. I show pictures and videos as I am progressing. Four months and then summer is over. Maybe I can hot-fire engine this year.

Advice me if you have good tips.

Edited June 8, 2017 by totalitor

[NSEP]

I wish i could do this, i draw rocket engines, but i cant really do fancy maths so i just got to "estimate" my stuff.

Awesome work. This is really interesting, probably the most awesome thing on the entire forums! 

[PrathamK]

Sry, I'm still studying but as soon I will read the whole and comment.

[PrathamK]

On 5/27/2017 at 10:02 PM, totalitor said:

Back to the business, now it is summer and I can work outside.

I build a fuel feeding system. I use nitrogen as a pressurant gas and 22 mm copperpipe as a fuel tank. I have integrated pressure regulator on nitrogen source, I can get 0-50 bar pressures. I am planning only short burning, up to 10 seconds. Calculated thrust is 29 N (2 lb) so I need only 0,02 l fuel to go. I tested system and it did worked well.

But now starts difficult part. Gaseous oxygen. I hoped I could find pressure regulator up to 25 bar, but I have now only 10 bar regulator. So chamber pressure would drop much. If I suppose chamber pressure 8 bar and feeding pressure 10 bar would this be enough?

How about chamber lenght? According my calculations it would be over 30 cm (chamber diameter is only 6,4 mm). With my tools I can not work with too big copper parts (I am brazing parts together). I would like to use large diameter chamber but I can't.

And cooling? Do I need cooling for 10 seconds?

This is very slow - but very interesting. I show pictures and videos as I am progressing. Four months and then summer is over. Maybe I can hot-fire engine this year.

Advice me if you have good tips.

Try to use some Ramjets, just KSP style, a sleek opening on 2 sides, with deep (a bit only) narrow channel will pressurize faster and Higher. But problem is On Launch, It will need some pressure by external source, Later as it gain spped, more pressure and (obviously) more thrust due to more Oxygen in Combustion Chambers. [ Tested ]

Use Recycled Materials, like Aluminum, from (Perfectly) cut Cans, or from Junk {New, purchase thin sheets and mold it with hands (Expert)}. Other material like Plastics (use only if you are Show Off Guy, or really Reporting and Cautious).

* I when 12 (2 year ago, if I played KSP Early, I would poat the Video) used two Cola Cans and a wide (narrow end) Aluminum Funnel as engine with those RamJets. Used BlackPowder to launch, In 6 sec, that white cloud changed black as powder ignited the Petrol, and it disappeared.

Fully made from Junk, Might have fallen in the Gorge near and me and my friend won First in Creatively Usage of Petrol too.

Sry for Typing much and wasting your Time.

Edited June 2, 2017 by PrathamK

[totalitor]

So I am building a rocket engine. I want to know if I can build it from ordinary stuff and can it achieve a stable combustion.

Yes I can build, here is some new pictures. A rocket engine is ready and nitrogen pressure feed system is ready and tested.

Still work to do. Oxygen feeding, valve controlling, ignition system, building a test stand.

But I am progressing.

 

 

[Mad Rocket Scientist]

8 hours ago, totalitor said:

So I am building a rocket engine. I want to know if I can build it from ordinary stuff and can it achieve a stable combustion.

Yes I can build, here is some new pictures. A rocket engine is ready and nitrogen pressure feed system is ready and tested.

Still work to do. Oxygen feeding, valve controlling, ignition system, building a test stand.

But I am progressing.

[...]

That's looking good!

[RoadRunnerAerospace]

okay, this is by far the coolest diy thing

[totalitor]

I found this:

http://watzlavick.com/robert/rocket/index.html

This is amazing. Check it out.

 

[totalitor]

New picture of my rocket engine project. Still thinking ignition. Otherwise all ready for test run. Coming august.

 

http://imgur.com/a/a4c0q

Edited July 10, 2017 by totalitor

[totalitor]

First ignition moved to year 2018. Winter break, coming back to business in May.

Latest pictures of my 5,5 kg thrust rocket engine:

 

http://imgur.com/a/fi1yO

[jyuan311]

Hey! I'm also trying to build a liquid fueled rocket engine. I was just curious. When you went to calculate the inner diameter of your cooling jacket. You used 357 instead of .357. Is that an error?

[totalitor]

I didn't calculate. I am using standard parts to this engine. Combustion chamber is a copper pipe 18 mm diameter. Cooling jacket is a copper pipe 22 mm diameter. Putting those together there is a cooling gap 1 mm. Smaller would be better, more speed for cooling liquid.

I really don't know if this engine works. I have all ready for next year summer hot fire test. Only oxygen gas bottle to buy. When I start the engine I am sure something would happen!

I made a channel on Youtube. Check this out:

https://www.youtube.com/channel/UCf2lLsBevPguEq7i2YKQ4Sg

Edited May 20, 2018 by totalitor

[totalitor]

Continuing work after winter. I changed from ethanol to gasoline and I try first uncooled rocket engine.

6,9 bar combustion chamber pressure, thrust 35 N.

All ready. Test run coming soon.

https://imgur.com/a/go736er

 

Edited May 20, 2018 by totalitor

[NSEP]

36 minutes ago, totalitor said:

Continuing work after winter. I changed from ethanol to gasoline and I try first uncooled rocket engine.

6,9 bar combustion chamber pressure, thrust 35 N.

All ready. Test run coming soon.

https://imgur.com/a/go736er

 

Awesome, can't wait to see it run!