Colored outer skin with prepreg base

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Colored outer skin with prepreg base

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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	Nah, I was not thinking a solid foam core, just a foam core layer between an outer and inner "skin" of CF... Good luck on the Engine testings. Cheers from just north of Aarhus "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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CopSub	CopSub posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 6, Visits: 26	Dravis (24/04/2015) As stated (Som skrevet står .. ) the outside colour of the Nosecone or other surfaces will have no influence on the temperature generated from Mach 1 to Mach 2 friction. The best thing to do in this case is make sure that the nosecone has the right shape! (I have a modified XL sheet that calculates various shapes using either the Von Kármán shape, or Power Series shape with n = 1/2) The hottest part will be the actual point, which I would probably make from a metal with a low thermal conductivity, bonded through the outside composite layer. (Titanium or stainless steel) I would make the cone a a sandwich construction using a foam core which will then insulate the inner composite layers from the friction heat. Even if the outer layers then get softened by the friction heat, the inner layers will be stable. An outer ablative layer of high temperature paint is also an option. The nosecone is already a nice Von Kármán Ogive The orange band is just for show A metal tip has been in my thoughts, as it also solves a couple of other problems. Unfortunately I can't give it a solid foam core, that space is already used by a ballute. But it might be possible to add some strategically placed foam ribs. Thanks for your input. BTW on the 1/5 and 2/5 we are running some tests on a throatless engine, they will be streamed live on youtube. Rune Henssel Copenhagen Suborbitals copenhagensuborbitals.com
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ChrisR	ChrisR posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	This stuff looks interesting http://www.buyaerogel.com/
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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	As stated (Som skrevet står .. ) the outside colour of the Nosecone or other surfaces will have no influence on the temperature generated from Mach 1 to Mach 2 friction. The best thing to do in this case is make sure that the nosecone has the right shape! (I have a modified XL sheet that calculates various shapes using either the Von Kármán shape, or Power Series shape with n = 1/2) The hottest part will be the actual point, which I would probably make from a metal with a low thermal conductivity, bonded through the outside composite layer. (Titanium or stainless steel) I would make the cone a a sandwich construction using a foam core which will then insulate the inner composite layers from the friction heat. Even if the outer layers then get softened by the friction heat, the inner layers will be stable. An outer ablative layer of high temperature paint is also an option. "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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CopSub	CopSub posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 6, Visits: 26	VVS (23/04/2015) I have no idea but putting ideas out! The guru's might know BUT could you spray the finished body with a white pigmented resin, would it spray, more so would it cross link, you could easily get a titanium white pigment and mix. 2k paint is good for 400 deg c. how hot is the surface of the rocket going to get? Will any gel coat take the heat. Hopefully it wont get to 400 degrees C I will make some tests with different techniques (painting, gelcoat, "self tinted epoxy", etc...) and figure out what works best. Rune Henssel Copenhagen Suborbitals copenhagensuborbitals.com
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CopSub	CopSub posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 6, Visits: 26	ChrisR (24/04/2015) The colour won't make a blind bit of difference in the terms you are talking about, it will all be about thermal conductivity of the materials and friction at those sorts of speeds. The only time the colour will make a difference is heat absorption from the sun when up in the atmosphere , hence why composite gliders/planes are painted white most of the time. A 2k urethane paint may be OK, something like Durpox white, with testing can be applied directly to the mould during layup but I don't know what it's temperature limit is. What can I say, I am a practical smurf and not a wiz at the physics part I will make some tests with different techniques (painting, gelcoat, "self tinted epoxy", etc...) and figure out what works best. Rune Henssel Copenhagen Suborbitals copenhagensuborbitals.com
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ChrisR	ChrisR posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	The colour won't make a blind bit of difference in the terms you are talking about, it will all be about thermal conductivity of the materials and friction at those sorts of speeds. The only time the colour will make a difference is heat absorption from the sun when up in the atmosphere , hence why composite gliders/planes are painted white most of the time. A 2k urethane paint may be OK, something like Durpox white, with testing can be applied directly to the mould during layup but I don't know what it's temperature limit is. CopSub (23/04/2015) I need the colored (white) outer skin because the black carbon fiber will absorb too much heat when traveling at MACH 1-2 Edited 10 Years Ago by ChrisR
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CopSub	CopSub posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 6, Visits: 26	Thanks, my eyes had missed that one. Rune Henssel Copenhagen Suborbitals copenhagensuborbitals.com
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*VVS*	*VVS* posted 10 Years Ago HOT Post Details
Group: Moderators Posts: 226, Visits: 334	I have no idea but putting ideas out! The guru's might know BUT could you spray the finished body with a white pigmented resin, would it spray, more so would it cross link, you could easily get a titanium white pigment and mix. 2k paint is good for 400 deg c. how hot is the surface of the rocket going to get? Will any gel coat take the heat. Edited 10 Years Ago by VVS
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panda	panda posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 47, Visits: 2.1K	https://www.easycomposites.co.uk/clearpol-iso-npg-clear-polyester-gelcoat This? Just use pigment to colour it the colour you want the final part to be in. Tom www.pandakayaks.co.uk
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