A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Technology
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Peroxide biprop ignition



 
 
Thread Tools Display Modes
  #11  
Old December 6th 03, 12:20 PM
Oren Tirosh
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Thanks Henry, John.

All else being equal, would you not prefer your 98% peroxide
stabilized? After all, stabilizers are not added by manufacturers to
make life harder for rocket builders. They are supposed to make
peroxide safer. You've explained why all else is not exactly equal but
the bottom line is a tradeoff between complexity perceived safety.
Such perceptions are not an exact science and are liable to change
quickly on certain circumstances.

Oren
  #12  
Old December 6th 03, 11:39 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

In article ,
Oren Tirosh wrote:
All else being equal, would you not prefer your 98% peroxide
stabilized? After all, stabilizers are not added by manufacturers to
make life harder for rocket builders. They are supposed to make
peroxide safer.


It's actually more a matter of making it less prone to deteriorate due to
contamination, and giving it a longer shelf life. I can't speak for John,
but if I were doing peroxide rocketry, I'd be willing to accept
constraints like a short shelf life and a need to be fussy about
cleanliness, in return for less hassle with catalyst poisoning etc.

All else being equal, yes, I'd be happier with *lightly* stabilized
peroxide using stabilizers compatible with my catalysts. (There is some
choice about just which stabilizers are used, and if you're buying in
bulk, you should have some voice in that decision.) The less fussy I have
to be about procedural details like cleaning and shelf life, the more time
and effort I can spend on design and development problems.

But there are a lot of assumptions in that (e.g, *are* there such
stabilizers?) and just getting it unstabilized might well be less hassle
all around.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |
  #13  
Old December 6th 03, 11:39 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

In article ,
Oren Tirosh wrote:
All else being equal, would you not prefer your 98% peroxide
stabilized? After all, stabilizers are not added by manufacturers to
make life harder for rocket builders. They are supposed to make
peroxide safer.


It's actually more a matter of making it less prone to deteriorate due to
contamination, and giving it a longer shelf life. I can't speak for John,
but if I were doing peroxide rocketry, I'd be willing to accept
constraints like a short shelf life and a need to be fussy about
cleanliness, in return for less hassle with catalyst poisoning etc.

All else being equal, yes, I'd be happier with *lightly* stabilized
peroxide using stabilizers compatible with my catalysts. (There is some
choice about just which stabilizers are used, and if you're buying in
bulk, you should have some voice in that decision.) The less fussy I have
to be about procedural details like cleaning and shelf life, the more time
and effort I can spend on design and development problems.

But there are a lot of assumptions in that (e.g, *are* there such
stabilizers?) and just getting it unstabilized might well be less hassle
all around.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |
  #14  
Old December 8th 03, 04:13 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

In article ,
Julian Bordas wrote:
I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?


Yes, definitely. As with any propellant combination, once it's lit it
will generally stay lit, modulo combustion-stability issues. People have
built rocket engines using peroxide as oxidizer with no catalyst at all,
just a conventional ignition system.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |
  #15  
Old December 8th 03, 04:13 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

In article ,
Julian Bordas wrote:
I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?


Yes, definitely. As with any propellant combination, once it's lit it
will generally stay lit, modulo combustion-stability issues. People have
built rocket engines using peroxide as oxidizer with no catalyst at all,
just a conventional ignition system.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |
  #16  
Old December 8th 03, 05:28 PM
Julian Bordas
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Henry Spencer wrote:


Restartable and reusable.


Subject to the need for yet another fluid system, with the added
complexity that entails.

The catalyst is mixed into the peroxide just before injection into the
chamber. This cannot be done safely with a fuel but catalytic
decomposition is slow enought to give some time for mixing.


I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?
  #17  
Old December 8th 03, 05:28 PM
Julian Bordas
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Henry Spencer wrote:


Restartable and reusable.


Subject to the need for yet another fluid system, with the added
complexity that entails.

The catalyst is mixed into the peroxide just before injection into the
chamber. This cannot be done safely with a fuel but catalytic
decomposition is slow enought to give some time for mixing.


I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?
  #18  
Old December 13th 03, 12:04 PM
Julian Bordas
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Henry Spencer wrote:
In article ,
Julian Bordas wrote:

I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?



Yes, definitely. As with any propellant combination, once it's lit it
will generally stay lit, modulo combustion-stability issues. People have
built rocket engines using peroxide as oxidizer with no catalyst at all,
just a conventional ignition system.


Thanks Henry. I'm one step closer :-)

Julian

  #19  
Old December 13th 03, 12:04 PM
Julian Bordas
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Henry Spencer wrote:
In article ,
Julian Bordas wrote:

I have real doubts about that part of the idea. Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together. Mixing *in* the chamber sounds both better
and safer.


Once the rocket is firing, is it possible to use non catalysed HTP?



Yes, definitely. As with any propellant combination, once it's lit it
will generally stay lit, modulo combustion-stability issues. People have
built rocket engines using peroxide as oxidizer with no catalyst at all,
just a conventional ignition system.


Thanks Henry. I'm one step closer :-)

Julian

  #20  
Old December 16th 03, 04:11 AM
Allen Meece
external usenet poster
 
Posts: n/a
Default Peroxide biprop ignition

Catalystic decomposition
will not be slow with high-concentration peroxide and an effective liquid
catalyst mixed well together.

I've only heard of solid catalyst beds. What's a [non-exotic] liquid catalyst
for HTP, [High Test Peroxide over 85% pure]?
^
//^\\
~~~ near space elevator ~~~~
~~~members.aol.com/beanstalkr/~~~
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cheap, easy to handle fuels/oxidizers Earl Colby Pottinger Technology 41 December 23rd 03 02:04 AM
OSP: reliability and survivability Edwin Kite Space Science Misc 77 September 26th 03 06:36 AM
Recommended TSTO technical papers? WvB Technology 14 September 4th 03 06:00 AM
Concentrating hydrogen peroxide Earl Colby Pottinger Technology 1 July 28th 03 07:59 AM


All times are GMT +1. The time now is 10:29 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.