Author Topic: Me163 Engine modeling  (Read 721 times)

Offline Sabre

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Me163 Engine modeling
« on: March 08, 2007, 02:43:38 PM »
I didn't see anything about this when I searched, though it may have been asked for before, but here goes anyway.

The engine in the 163 is a chemical rocket; however, it is modeled for purposes of engine start and stop as if it's a turbine.  Push the "E" button and you hear it start to spool up like the 262 or Arado, with a subsequent pause before thrust begins.  This is not how a rocket works (I'm in the space business).  A rocket is not "started"; it is ignited.  Early rockets weren't throttle controlled, but reached full thrust almost instantly.  Admittedly, I'm not an expert in the 163, but I'd bet dollars to donuts its engine ignited almost instantly, whether there was a throttle mechanism or not, and did not take 10+ seconds to begin producing thrust.

I don't know if this is modeled the way it is because the present code version requires it, or because it's just an oversite never corrected.  If the latter, I'd sure like to see this fixed.
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Offline Krusty

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Me163 Engine modeling
« Reply #1 on: March 08, 2007, 03:01:57 PM »
The 163 did have a throttle and I believe it was restartable, but as for how fast it kicked in? Good observation! I never thought of that.

Offline FrodeMk3

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Me163 Engine modeling
« Reply #2 on: March 08, 2007, 03:06:36 PM »
Being a Hypergolic, binary fuel, which ignites on simply mixing it together, It would have to be as soon as fuel mixed in the combustion chamber.

Offline Krusty

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Me163 Engine modeling
« Reply #3 on: March 08, 2007, 03:12:54 PM »
Yes but it does have to mix. It would take a couple of seconds to get to full power (but not like the current modeling).

Offline Bronk

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Me163 Engine modeling
« Reply #4 on: March 08, 2007, 03:31:28 PM »
Quote
Originally posted by FrodeMk3
Being a Hypergolic, binary fuel, which ignites on simply mixing it together, It would have to be as soon as fuel mixed in the combustion chamber.


And wouldn't variable regulation of the flow to the combustion chamber be a "throttle"?


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Offline Puck

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Me163 Engine modeling
« Reply #5 on: March 08, 2007, 05:29:35 PM »
As a rule throttling was achieved by diverting some of the T-Stoff (hydrogen peroxide[1]) in to the cockpit.  More than one pilot got eaten by that stuff, even after landing successfully.  Another neat trick was accidentally using the same bucket when loading T-Stoff and C-Stoff (Methanol/Hydrazine).  The same guy never did that twice.

This from my memory of reading "Rocket Pilot" and subsequent research many years ago on the subject.

[1] This is NOT the stuff under your bathroom sink...that's about 3% when it's bottled, closer to 1% or 2% by now.  This stuff was nearly pure and would eat through a person, as in MELT them.  Very unpleasant, very unstable, very nasty.  Getting C-Stoff sloshed on you was not an improvement.
//c coad  c coad run  run coad run
main (){char _[]={"S~||(iuv{nkx%K9Y$hzhhd\x0c"},__
,___=1;for(__=___>>___;__<((___<<___<<___<<___<<___
)+(___<<___<<___<<___)-___);__+=___)putchar((_[__
])+(__/((___<<___)+___))-((___&

Offline Grant Pratt

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ME-163 at night
« Reply #6 on: April 06, 2007, 02:51:34 PM »
I just read a report of the only recorded engagement of a 163 at night.  A 163 vs a P-61 it was seen throuteling up and down in the dog fight. there was no victor but dose show that there was a throtleable eng. as far as reaction time it shoud be near instant, the feul was hypergaulic. ( reacts getween t-stof and c-stof on contacts no spark needed.) I hope this helps.

Offline Anyone

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Re: Me163 Engine modeling
« Reply #7 on: April 07, 2007, 04:07:04 AM »
Quote
Originally posted by Sabre
I didn't see anything about this when I searched, though it may have been asked for before, but here goes anyway.

The engine in the 163 is a chemical rocket; however, it is modeled for purposes of engine start and stop as if it's a turbine.  Push the "E" button and you hear it start to spool up like the 262 or Arado, with a subsequent pause before thrust begins.


those noises you could try explain by the fuel pumps/turbines maybe??? I not totally sure.

Quote
Originally posted by Sabre
This is not how a rocket works (I'm in the space business).  A rocket is not "started"; it is ignited.  Early rockets weren't throttle controlled, but reached full thrust almost instantly.  Admittedly, I'm not an expert in the 163, but I'd bet dollars to donuts its engine ignited almost instantly, whether there was a throttle mechanism or not, and did not take 10+ seconds to begin producing thrust.

I don't know if this is modeled the way it is because the present code version requires it, or because it's just an oversite never corrected.  If the latter, I'd sure like to see this fixed.


163 rocket can be throttled, just like rockets today by limiting fuel to the combustion chamber.

and last comment about rockets not taking time to produce thrust... Rockets on the shuttle arnt a "instant" start up, it takes time for fuel to prime up etc, Im no expert and im just going from memory here, but arnt the fuel pumps going for almost 7 seconds before they ignite the fuel?

 163 is the same. Theres a video on youtube somewhere of a 163 pumping LOADS of liquid fuel out before the engine starts burning (slowly), then theres even more time while the 2nd fuel is slowly added and the engine starts to burns fast enough to produce thrust.


now solid rocket boosters are different, they ARE instant, and arnt really controlable by throttle.

Offline AWwrgwy

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Me163 Engine modeling
« Reply #8 on: April 07, 2007, 08:09:03 PM »
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Offline Benny Moore

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Me163 Engine modeling
« Reply #9 on: April 07, 2007, 08:25:37 PM »
Quote
Originally posted by Puck
As a rule throttling was achieved by diverting some of the T-Stoff (hydrogen peroxide[1]) in to the cockpit.  More than one pilot got eaten by that stuff, even after landing successfully.  Another neat trick was accidentally using the same bucket when loading T-Stoff and C-Stoff (Methanol/Hydrazine).  The same guy never did that twice.

This from my memory of reading "Rocket Pilot" and subsequent research many years ago on the subject.

[1] This is NOT the stuff under your bathroom sink...that's about 3% when it's bottled, closer to 1% or 2% by now.  This stuff was nearly pure and would eat through a person, as in MELT them.  Very unpleasant, very unstable, very nasty.  Getting C-Stoff sloshed on you was not an improvement.


That's very interesting; the local Mein Kampf club on this board has been insisting that this chemical was not corrosive.  "Perfectly safe," they called it in the last thread.  They're quite willing to believe Mr. Galland when it comes to him bashing United States fighters (never mind that he later retracted it), but they discredit him when he says that the Me-163's rocket fuel melted pilots.  Isn't that cute?

Offline Kweassa

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Me163 Engine modeling
« Reply #10 on: April 08, 2007, 02:07:24 AM »
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...the local Mein Kampf club...


 I see your vocabulary choice for those who don't agree with you have been growing more colorful.


Quote
"Perfectly safe," they called it in the last thread.


 No, they called the 163 "perfectly safe" to fly, and they quoted Rudy Opitz to overturn some urban legends about the 163. No one in that thread ever mentioned the fuel was "perfectly safe".


Quote
They're quite willing to believe Mr. Galland when it comes to him bashing United States fighters (never mind that he later retracted it), but they discredit him when he says that the Me-163's rocket fuel melted pilots. Isn't that cute?


 We can use this simplistic logic in just the opposite manner.

 Someone who discredits Galland by claiming "he defends Nazi equipment", all of a sudden takes his word so importantly to put it above the word of the chief test pilot directly involved in the plane's development history?

 What does Rudy Opitz have to say about it?

Quote
When fuel contacted organic material, including skin, it ignited after only a few seconds.


 ... and what he has observed is right, because hydrogen peroxide of high concentration reacts differently from what one would imagine in bathroom cleaning liquids.
 
 So, tell us, ye "pilot would melt" mythmongers, how the T-Stoff would "melt" a pilot, when;

Quote
1. Above roughly 70% concentrations, hydrogen peroxide can give off vapor that can detonates above 70 ¡ÆC (158 ¡ÆF) at normal atmospheric pressure. This can then cause a boiling liquid expanding vapor explosion (BLEVE) of the remaining liquid.

2. Hydrogen peroxide vapors can form sensitive contact explosives with hydrocarbons such as greases. Hazardous reactions ranging from ignition to explosion have been reported with alcohols, ketones, carboxylic acids (particularly acetic acid), amines and phosphorus. The saying is 'peroxides kill chemists'.

3. Hydrogen peroxide, if spilled on clothing (or other flammable materials), will preferentially evaporate water until the concentration reaches sufficient strength, then clothing will spontaneously ignite. Leather generally contains metal ions from the tanning process and will often catch fire almost immediately.

4. Concentrated hydrogen peroxide (>50%) is corrosive, and even domestic-strength solutions can cause irritation to the eyes, mucous membranes and skin. Swallowing hydrogen peroxide solutions is particularly dangerous, as decomposition in the stomach releases large quantities of gas (10 times the volume of a 3% solution) leading to internal bleeding. Inhaling over 10% can cause severe pulmonary irritation.


 Spill sufficiently enough quantities of T-Stoff on your clothes, and you'd be seriously burnt. Spill sufficiently enough quantities of T-Stoff on a protective nylon suit, and the liquid will eventually eat its way through the suit, and then either it ignites and explodes, or 'melts' the pilot.

 Only question is, what kind of idiot would settle down and wait for a bucket load of T-Stoff to eat away his suit until finally it comes in contact with his skin to 'melt' him? Not to mention hydrogen peroxide of high concentration, in its nature being so severely unstable that it would in most cases ignite before it even has a chance to react to organic material long enough to actually corrode them?

 If you're imagining a pretty picture of someone drowning in a leaking 163, and then melting away as if he fell into a pool of acid, then you'd be seriously wrong.

 If enough 163 fuel spilled into the cockpit to be really fatal, the chances are the pilot is either engulfed in flames by spontaneous ignition by fuel, or knocked unconcious due to toxic gas and crashes to death.

 The "melt" is a pure urban legend.


Quote
That's very interesting....


 Nothing interesting about it. Simply, Puck's wrong.
« Last Edit: April 08, 2007, 02:11:29 AM by Kweassa »