Author Topic: Greetings All  (Read 714 times)

Offline British Reaction Research

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Greetings All
« on: August 07, 2017, 04:47:02 AM »
Hello,

My name is Carl and I'm in the UK, in the Highlands. I have a reasonably decent workshop with a Harrison M250 lathe, Chester Mill Drill and an RTECH Tig welder.

I've included some pictures showing my lathe, mill, welder and one of my rotary tables that I put an Arduino controlled stepper on.

My main project is building a liquid fuelled rocket engine. You can read about this on my blog, British Reaction Research.

I get involved with other things too and I also dabble in electronics. I'm building a tensile testing machine to test the strength of aluminium welds. I bought an old pottery kiln to heat treat the welds.

In the lathe you can see a nozzle for the rocket emerging from a piece of 6082 T6.

All the best,

Carl.

Offline philf

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Re: Greetings All
« Reply #1 on: August 07, 2017, 05:23:14 AM »
Hi Carl,

Welcome.

A nice tidy workshop you have there.

But....

Before someone else tells you - your pictures are too big! 800 x 600 pixels is more than big enough so that other forum members can see the whole picture at one time without having to scroll up and down.

Cheers.

Phil.
Phil Fern
Location: Marple, Cheshire

Offline Joules

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Re: Greetings All
« Reply #2 on: August 07, 2017, 05:39:56 AM »
Hi Carl, Paul Kelly is a guy you might want to speak too, he's into rocketry.
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Offline awemawson

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Re: Greetings All
« Reply #3 on: August 07, 2017, 06:04:40 AM »
Hi Carl welcome aboard  :thumbup:

I'd love to see your photos when I can fit them into my barn  :lol:
Andrew Mawson
East Sussex

Offline British Reaction Research

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Re: Greetings All
« Reply #4 on: August 07, 2017, 07:12:10 AM »
Hi All,

Thanks for the welcome and I will take note about the pictures!

Carl.

Offline AdeV

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Re: Greetings All
« Reply #5 on: August 07, 2017, 12:55:08 PM »
Welcome to the collective Carl!  :borg: You know there's no escape, right?  :lol:

Anyway...


My main project is building a liquid fuelled rocket engine. You can read about this on my blog, British Reaction Research.


You can't mention a home-made liquid fuelled rocket and not show any pictures, that's just cruel!
 :worthless:

I have an old book here called "Design of liquid, solid and hybrid rockets"... one day I intend to blow myself and half the neighbourhood up trying to launch a rocket to the moon  :ddb: (only kidding, GCHQ!)
Cheers!
Ade.
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Offline British Reaction Research

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Re: Greetings All
« Reply #6 on: August 07, 2017, 02:53:09 PM »
I doubt most of my pictures would solicit that much interest. The whole process of building a liquid fuelled rocket engine that can be run safely without exploding, melting or both is one that is fraught with obstacles.

Most of the work I have done so far has been of a nature of basic research. Experimenting with different types if injectors, different construction methods for the chamber and heat treatment for welding aluminium.

If you are interested you can check out my blog for more information.

All the best

Carl.

Offline krv3000

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Re: Greetings All
« Reply #7 on: August 07, 2017, 04:18:21 PM »
hi and welcome

Offline British Reaction Research

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Re: Greetings All
« Reply #8 on: August 07, 2017, 04:47:50 PM »
Thank you!

Carl.

Offline Biggles

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Re: Greetings All
« Reply #9 on: August 12, 2017, 12:30:29 PM »
Hi Carl and Welcome, at least one of the members have dabbled in rocket propelled vehicles. If you need any help with ideas and building, doubleboost made a rocket propeller go cart some years ago and I think itís still on his YouTube channel.  :smart:

Offline howsitwork?

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Re: Greetings All
« Reply #10 on: August 14, 2017, 02:16:53 PM »
Hi Carl and welcome. I too struggle with the photo sizes.

Ian

Offline Pete W.

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Re: Greetings All
« Reply #11 on: August 14, 2017, 02:43:54 PM »
Hi Carl and welcome. I too struggle with the photo sizes.

Ian


Download FastStone Resizer, the link is in the 'Gallery' thread and it's free.  It's very versatile and capable and very user friendly once you've invested a half-hour or so to climb the learning curve. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline PK

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Re: Greetings All
« Reply #12 on: August 14, 2017, 04:59:38 PM »
Hi Carl, Paul Kelly is a guy you might want to speak too, he's into rocketry.

Yep, I've made one or two over the years.
What flavor of rocket takes your fancy Carl?

PK

Offline Groundhog

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Re: Greetings All
« Reply #13 on: August 15, 2017, 11:08:09 AM »
To see the pictures at a size for your screen Right Click on the picture and then chose & click on "View Image".
Racers say that horsepower is how fast you hit the wall and torque is how big of a hole you make.

Offline awemawson

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Re: Greetings All
« Reply #14 on: August 15, 2017, 11:17:32 AM »
That probably depends on which operating system and browser that you are using.

.... it certainly doesn't work in Chrome under Windows 7

The attached (640 x 480 !!!!) image is what happens with the first picture in this thread when 'right clicking'
Andrew Mawson
East Sussex

Offline seadog

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Re: Greetings All
« Reply #15 on: August 15, 2017, 12:41:08 PM »
Or in Win 10 Andrew. If you open in a new tab you do get an image you can view in one, but it's a pain to have to do it for a lot of images.

Offline AdeV

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Re: Greetings All
« Reply #16 on: August 15, 2017, 04:09:19 PM »
Andrew - click on "Open Image in New Tab", this will then auto-size to full-screen. Clicking on the image will then zoom it to full size, clicking again will once again fit it to your screen.

As Seadog says - a bit of a nuisance if there's lots of images, but OK if there's just one or two.
Cheers!
Ade.
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Or: Zhengzhou, China. An even longer way from anywhere...
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Offline British Reaction Research

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Re: Greetings All
« Reply #17 on: August 15, 2017, 05:59:48 PM »
Doubleboost's go kart is an astonishing piece of engineering. It's a jet engine though. I'm building a rocket engine. It is a liquid fuelled engine using isopropyl alcohol as the fuel and nitrous oxide as the oxidiser.

The fuel is used as a coolant in a jacket surrounding the combustion chamber and nozzle. This is called regenerative cooling. The fuel is mixed with water to increase its heat capacity. Also a small amount of silicon oil is added. When this burns with the fuel it creates a continuously renewing and very thin glass like substance on the chamber walls. This acts like an insulating shield to reduce to transfer if heat to the chamber walls.

Offline PK

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Re: Greetings All
« Reply #18 on: August 16, 2017, 06:30:08 AM »
I'm building a rocket engine. It is a liquid fuelled engine using isopropyl alcohol as the fuel and nitrous oxide as the oxidiser.
Will you have enough flow? even if you went really fuel rich then you're still talking, what, 5:1 o/f?

The lack of oxygen by weight and the reasonably high heat of formation make NOX a reasonably unattractive choice for fuel cooled regen.

I once built an ox cooled NOX biprop.... Pyrovalve ignition, worked really well until it ran out of liquid N20, then it ate itself....
If I'd just used something like a floating ball to plug the feed when it transitioned to gaseous mode it may have survived.
PK

Offline British Reaction Research

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Re: Greetings All
« Reply #19 on: August 16, 2017, 02:03:16 PM »
Hi PK,

Thanks very much for your interest and your comments.

I don't fully understand though. Why would I not get enough flow? And are you saying you built a Nox cooled motor?

Sorry for being slow on the uptake,

Carl.

Offline PK

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Re: Greetings All
« Reply #20 on: August 16, 2017, 07:59:58 PM »
I don't fully understand though. Why would I not get enough flow?

Apologies if this is (as we say in my country) telling you how to suck eggs, but a simple explanation will probably be useful for the non rocket nerds  of this non rocketry forum.

In the simplest sense, a rocket motor cooled by one of it's propellants (usually the fuel because hot oxidiser is nasty) flows that propellant over the outer walls of the chamber at a rate and velocity sufficient to
a: Extract enough heat from the chamber walls to prevent them from melting,
b: Not raise the temperature of the propellant past it's boiling point at the local pressure.

IPA has a fairly low boiling point at the 300-400psi you are going to see inside your cooling channels (I'm assuming that you'll pressurise the fuel tanks to 600+PSI), so you need to flow a lot of it to remove enough heat without getting local boiling and hence hotspots. This is one of the reasons kerosene is a popular fuel. You do this by increasing the velocity of the fuel in the cooling jacket, which increases the pressure drop which drops the boiling point..... welcome to rocket design.

This isn't a too much of a problem until you consider that nitrous oxide doesn't have a lot of oxygen in it, so you don't need a lot of fuel (by weight) to run near a stoichiometric point OTTOMH it's about 6:1.
Again this doesn't sound so bad, because less fuel == less burning == less heat right?  The kicker is that the decomposition of N2O is reasonably exothermic, so you are getting heat from a process that doesn't require fuel flow. That extra heat generally means that you'll struggle to get enough fuel flow to cool the chamber without boiling.

All biprops also use boundary layer cooling, which might get you out of trouble as much by increasing the fuel flow rate as by direct shielding of the walls.



Now this is a lay mans description. There is, of course, maths to work all this stuff out.

Quote

 And are you saying you built a Nox cooled motor?

Well, it was a NOX cooled motor for about 4 seconds, then it was a self digesting fireball, then a bucket of molten shrapnel.

I've built a radiation cooled NOX biprop that worked, but it was done before we figured out how to do reliable ignition so it was a pig to start...
I'll have a pic somewhere, but it was based on this:



PK

Offline British Reaction Research

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Re: Greetings All
« Reply #21 on: August 19, 2017, 04:30:40 AM »
Hello Paul,

This is just a quick reply to acknowledge your highly knowledgeable and informative post.

I'm glad to say that I have my head around (most) of the maths involved in motor design. No problem with the egg suck approach. I'm British so I know the saying and appreciate the style. Simplest explanations are the best and often reveal far more that the complex involved ones.

I'll post again with more info soon. I'm going to start a separate thread for my project. Meantime you can look at my blog, British Reaction Research.

Thanks again,

Carl.