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Latest candidate for SpaceX pad explosion



 
 
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  #21  
Old October 20th 16, 02:35 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Latest candidate for SpaceX pad explosion

Jesus H. Christ. IT'S A ****ING ***WRAP***. There is no 'lamination'
to 'delaminate'. It is NORMAL for liquid oxygen to get inside the
overwrap, but as pressure on the overwrap increases (due to pressure
in the LOX tank) the LOX in the overwrap will squeeze back out, just
like wringing a wet towel. A solid cannot do that, which means it's
trapped in the layers. Eventually it will go back to liquid, but it
is now under very high pressures.

If you're not getting this yet, perhaps you should just accept that
you're not able to get it and either go educate yourself or move on.

JF Mezei wrote:

On 2016-10-19 09:30, Fred J. McCall wrote:

around the helium tank to provide structural support. Oxygen getting
inside the overwrap exposes LOX to carbon.


Assuming there is a non combustible overwrap to prevent contact of LOX
with carbon fibre, would it be fair to assume that the first failure
would have been failure of this to prevent LOX from coming in contact
with the carbon fibre or resin that covers it?

"getting inside the overwrap" paints a picture of delaminated carbon
fibre layer and liquid managing to infiltrate insite. But wouldn't
combustion happen well before LOX gets inside the delaminated space as
it would combust upon first contact with carbon overwrap ?

aka: LOX would have to be in contact with carbon well before it starts
to infiltrate between delaminated carbon layers.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #22  
Old October 20th 16, 02:43 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:

On 2016-10-19 10:07, Fred J. McCall wrote:

We're past that. The question is WHY the helium tank cracked.


So at what point would combustion have begun ? when LOX comes into
contact with the carbon over the helium tank, or LOX simply creating
mechanical failure of the HE2 tank, causing overpressure and mechanical
failure of LOX tank, at which point ignition happened on anything
conbustible around it ?


Neither.


or put another way: did ignition begin on the carbon fibre overwrap of
He2 tank, or did it begin after the LOX tank failed, releasing LOX
everywhere ?


That's certainly 'another way', but it's not the same question. Let
me see if I can make this simple enough so that even you get it.

1) LOX infiltrates layers of overwrap
2) Some LOX freezes (SOX?)
3) LOX tank pressure rises
4) Any LOX in layers of overwrap wrings out
5) SOX stays where it was
6) Increasing pressure initiates reaction.
7) Small boom
8) Helium tank breeches, causing massive overpressure in LOX tank
9) LOX tank blows out, including breeching kerosene tank next door
10) Big boom.

Are you getting this yet?


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #23  
Old October 20th 16, 11:09 AM posted to sci.space.policy
Jeff Findley[_6_]
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Default Latest candidate for SpaceX pad explosion

In article m,
says...

On 2016-10-19 21:35, Fred J. McCall wrote:
Jesus H. Christ. IT'S A ****ING ***WRAP***. There is no 'lamination'
to 'delaminate'.



Do you understand how composite materials are made ?


Fred does. You don't. Here is a NASA "primer" on COPV:

https://ston.jsc.nasa.gov/collection...P-2011-573.pdf


From above:

As the fiber/resin composite is generally not considered pressure
tight, the composite is applied over a fluid-retention barrier
that serves as an interior liner for the composite.

The above is what you don't get. The primary reason a COPV has a liner
is because of the porosity of the composite overwrap. Yes, it's nice to
have that barrier to help serve as the form for wrapping the composite,
but note that it might be possible to come up with a manufacturing
technique which would make that form removable (e.g. could be an
inflatable which could be deflated once the composite wrap is complete).
But no one has done that, because then the pressure vessel would be like
a bucket with a bunch of holes in the bottom!

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
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  #24  
Old October 20th 16, 11:18 AM posted to sci.space.policy
Jeff Findley[_6_]
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Default Latest candidate for SpaceX pad explosion

In article . com,
says...

On 2016-10-19 21:43, Fred J. McCall wrote:

1) LOX infiltrates layers of overwrap


If a liquid can get between layers of a carbon fibre structure, the
carbon fibre structure has been compromised and has lost much strength.


This is factually incorrect! Read this cite (also posted in another
reply to you):

https://ston.jsc.nasa.gov/collection...P-2011-573.pdf

From page 2 (of the document, which is page 8 in the PDF):

Continuous fibers provide tensile strength for structural
integrity while the resin carries shear loads in the composite
and maintains the fiber position. As the fiber/resin composite
is generally not considered pressure tight, the composite is
applied over a fluid-retention barrier that serves as an
interior liner for the composite. These fluid retention
barriers may be a rubber, plastic, or thin ductile metal liner.
These liners serve to maintain acceptable leak rates and fluid
purity but add little, if any, structural integrity.

Read that several times if you must. It is the bit you're clearly not
getting.

2) Some LOX freezes (SOX?)
3) LOX tank pressure rises


I should not rise since equal volume of gas is vented as equal volume of
LOX is poured into tank (via release valve).


Bull****. The sub-cooled LOX comes into the pipe leading to the stage
at a pressure higher than that in the tank. If the pressure wasn't
higher in the pipe, it would not flow into the tank in the first place!

Also, if the temperature of the tank is so low that LOX freezes, it will
not have a desire to boil off and as a result, would not increase tank
pressure even if relief valve didn't exist.


Using "slush" propellants has been proposed in the past. Clearly SpaceX
is trying to get close to those temperatures at the time of launch.

4) Any LOX in layers of overwrap wrings out


And pray tell, how come some LOX that has infiltrated the carbon fibre
does not immediately ignite it ? perhaps they use a magical carbon that
doesn't oxydyze ?


Because the carbon fiber overwrap is not meant to hold pressure *at
all*. Read the frigging cite from NASA on COPVs!

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #25  
Old October 20th 16, 05:17 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:

On 2016-10-19 16:24, Jeff Findley wrote:

I doubt it. What coating would be LOX compatible and not crack due to
the expansion and contraction of the COPV during normal fills and drains
while inside the LOX tank?


But doesn't the coating inside the COPV do exactly that ?
(expand/contract during normal fills) ?


What "coating inside the COPV" would that be, exactly?


It's be driven into me that the second LOX comes into contact with
combustible material, it causes very fast combustion.


Educate yourself.


So I do not understand how LOX being in contact with carbon fiber would
not cause instant combustion.


So you don't understand how any pressure fed rocket can work.
Congratulations.


No ignition source.


If you pour LOX onto BBQ charcoal, it instantly burns, without a match
to ignite it. So why would it magically not do that in a tank if there
is some carbon present and in contact with LOX ?


Because it doesn't do that with charcoal unless the charcoal is hot?


No, the overwrap was trying to squeeze the oxygen back out, but could
not, so the theory is the overwrap failed (I'm guessing at or near the
location of the solid oxygen).


I see a problem with that. To be structurally strong, layers of
composites (either carbon or glass fibre) have to be very tightly
laminated against each other with resin holding them together.


Bull****. Do you know what 'laminated' means?

snip silly hypothetical


In my mind, it would be more likely the helium tank got so cold that the
carbon fibre became brittle and failed, releasing helium into the LOX
tank, causing that tank to rupture and then things went kablooey.


And your mind is precisely why you are NOT in the rocket business.


It means solid oxygen. Like how ice is solid water.


You've obviously never seen slush ? water at 0° can exist both solid
and liquid. And slush has solid "flakes" of water mixed with liquid
water. (think milk shake or a "Slush" drink).

I find it unlikely that the LOX became a solid block of "solid". Far
more likely it would have been a "slush" type of mixture which is still
adaptable to shape changes.


I find it unlikely that you know more than people who do this **** for
a living.


Filling them from what? Is a compressor involved? If so, that
compressor *increases* the pressure of the gas which increases the
temperature of the gas. Clearly you can't do that with LOX and expect
it to be "sub-cooled" in the rocket. So clearly SpaceX isn't doing it
that way.


Making any gas liquid is an exothermal reaction. (either you compress
the gas (exothermal) or you cool it (exothermal).


while you're looking up what 'laminate' means, look up 'exothermal' as
well. But you'll have to look up 'exothermic', since 'exothermal'
isn't a word.

Hint: There is no 'reaction'.

snip silliness


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #26  
Old October 20th 16, 05:18 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:

On 2016-10-19 21:35, Fred J. McCall wrote:

Jesus H. Christ. IT'S A ****ING ***WRAP***. There is no 'lamination'
to 'delaminate'.


Do you understand how composite materials are made ?


Do you understand how a COPV is made, you ignorant ****?


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #27  
Old October 20th 16, 05:23 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Latest candidate for SpaceX pad explosion

Christ, believe whatever stupid things you want to. I'm tired of
trying to explain things to you.

JF Mezei wrote:

On 2016-10-19 21:43, Fred J. McCall wrote:

1) LOX infiltrates layers of overwrap


If a liquid can get between layers of a carbon fibre structure, the
carbon fibre structure has been compromised and has lost much strength.


Did you do the experiment I suggested to you with the Ace bandage? Did
you try opening your fist?


2) Some LOX freezes (SOX?)
3) LOX tank pressure rises


I should not rise since equal volume of gas is vented as equal volume of
LOX is poured into tank (via release valve).


Wrong.


Also, if the temperature of the tank is so low that LOX freezes, it will
not have a desire to boil off and as a result, would not increase tank
pressure even if relief valve didn't exist.


So you never heard of hot spots and cold spots and think that the
whole LOX tank contents must go solid?


4) Any LOX in layers of overwrap wrings out


And pray tell, how come some LOX that has infiltrated the carbon fibre
does not immediately ignite it ? perhaps they use a magical carbon that
doesn't oxydyze ?


Perhaps you're an ignorant ****.


8) Helium tank breeches, causing massive overpressure in LOX tank
9) LOX tank blows out, including breeching kerosene tank next door
10) Big boom.


I agree with 8 9 10. Once helium tank loses integrity and releases all
the hekium in one shot, it is too much of LOX tank to take and it also
suffers a breach.


I don't give a **** what you 'agree with'. You're welcome to be as
stupidly wrong as you care to be.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #28  
Old October 21st 16, 11:34 PM posted to sci.space.policy
Rick Jones[_6_]
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Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:
On 2016-10-20 12:17, Fred J. McCall wrote:


Because it doesn't do that with charcoal unless the charcoal is
hot?


I have seen videos of LOX being poured onto cold charcoal years ago
on TV. Not pretty.


Are you quite certain it was just cold charcoal sitting there with no
flame source nearby? Everything I've seen in an admittedly cursory
web search has involved lighting a charcoal grill where there was
already an open flame - scrap of paper on the pile, that sort of
thing.

rick jones
--
The computing industry isn't as much a game of "Follow The Leader" as
it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose."
- Rick Jones
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...
  #29  
Old October 22nd 16, 04:48 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:

On 2016-10-20 06:09, Jeff Findley wrote:

Fred does. You don't. Here is a NASA "primer" on COPV:

https://ston.jsc.nasa.gov/collection...P-2011-573.pdf



Did you read this article, you ignorant yammerhead? It seems not.


Delamination is one of the core "stress failure" modes.


THERE IS NO LAMINATION, YOU IGNORANT ****!!!!


That article
failes to underline that the various layers of fibres wound over each
other are bound by the resin and gain more strength that way. When the
binding between layer weakened or broken (delamination), the streength
is very much weakened.


Did you find the word 'laminate' or 'lamination' ANYWHERE in that
article? No, you did not, BECAUSE THERE IS NO LAMINATION, YOU
IGNORANT ****.


This is one of the problems Boeing experienced when it started to test
the 787 fuselages.


That's nice, but we're not talking about a B787 fuselage here. Go
read the article you were provided with again.


The above is what you don't get. The primary reason a COPV has a liner
is because of the porosity of the composite overwrap.


This porosity is not quantified in that article. Are you intending to
keep the pressurized gas at same pressure for 5 months or 2 hours ?

As well, the porosity is not qualified in whether there are actual gaps
in material, or whether the passing of pass from one side to the next
happens at almost molecular level (as it does with bicycle tires for
instance, they lose pressure over days, not minutes).


Go read the article you were provided with again. It makes it plain
that the liner is A FLUID BARRIER. In other words, the composite
overwrap by itself does not retain fluid.

snip material about how COPVs are *NOT* made


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #30  
Old October 22nd 16, 04:57 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Latest candidate for SpaceX pad explosion

JF Mezei wrote:

On 2016-10-20 12:17, Fred J. McCall wrote:

What "coating inside the COPV" would that be, exactly?
Educate yourself.


The liner.


The liner is not a 'coating', you idiot.


And your insults still provide no explanation on how they prevent LOX
which is in direct contact with carbon fibre (which surrounds the
embedded helium tank) from bursting into flames.


Because no explanation is required. I also haven't explained why
water is wet or why things don't fall up.


Because it doesn't do that with charcoal unless the charcoal is hot?


I have seen videos of LOX being poured onto cold charcoal years ago on
TV. Not pretty.


Given your performance here, I'd bet you didn't know what the **** you
were looking at. With no ignition source nothing happens and you can
happily soak charcoal in LOX until it's saturated. Of course, once
you do that and then expose it to an ignition source it explodes quite
violently.

http://www.bkinzel.de/misc/ghg/

Now you can post your cite of LOX being poured onto cold charcoal WITH
NO IGNITION SOURCE PRESENT.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
 




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