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#41
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 2:59*pm, (John Clear) wrote:
In article , Alan Dicey wrote: Indeed. *The shuttle tiles have astonishing insulation properties, but are composed of 10% silica fibres, 90% air with a borosilicate glass coating and have no load-bearing capacity to speak of. *They would be crushed by the first person to walk on them, never mind an aircraft tyre.. Most of the white areas on the top of the shuttle are nomex blanket type material. *Blending something like that in with non-skid coating shouldn't be too hard to do, and provide enough thermal insulation. John -- John Clear - * * * * * * * * * * * *http://www.clear-prop.org/ Still not really durable enough to handle aircraft weight. Was less heat resistant than bottom portion. Think of it this way, bottom part gets really hot on reentry, shields top part. You could see some scorch marks on most of the post landing photos. Looks like little black scuff marks on foreward part near wing. Probably looks like a back to the drawing board moment. Oh, hey, anybody figure out we're landing on a carrier and we have some really high exhaust temps.... Remember the old drawing that went around what aerodynamicist built, weapons guys, all that, and what the customer wanted. Nothing changes. |
#42
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 2:41*pm, "Ken S. Tucker" wrote:
On Dec 10, 11:04 am, Jack Linthicum wrote: On Dec 10, 2:00 pm, "Ken S. Tucker" wrote: On Dec 10, 7:24 am, Jack Linthicum wrote: On Dec 10, 8:53 am, "Roger Conroy" wrote: "Bill Kambic" wrote in message .. . On Thu, 10 Dec 2009 02:57:36 -0800 (PST), Jack Linthicum wrote: snipped for brevity Or use the rocket launch technique and spray water across the take-off area. Probably less than optimal. *Large clouds of hot, salt water steam would be an annoyance (at a minimum) to the deck crew. *It would also be a highly corrosive material that could serious complicate maintenance of both ship and aircraft. Use of fresh water would likely be an excessive demand on the evaporators. The piping of cooling water suggested earlier would be a better idea. It would likely be cheaper that major modifications such as a "ski jump" and permit the continued use of the vertical capability of the aircraft. A water cooled heatsink built into a part of the deck designated for "hot" aircraft makes a lot of sense. You could have a place underneath to stash beer, like the old sub- mariners did. In electronics, we have similiar problems, we usually solve using Al heat sinks, fan air cooled, as the cheapest. Screw a few Al heat sinks to the bottom of the locations of the deck permited to take the heat and engage any fluid to cool it, even water if space is tight, yawn.. Ken Troll them in the water, saves having all those pipes. In conventional PC's like you prolly have, is a small fan sitting on the CPU Al heat sink. In the high watt stuff, oil circulation is used to cool the active components I've used. I'm not keen on oil, a friend of mine had a damn transformer explode on him and was showered with burning oil, it was not pretty, and is very painful. Also in my experience, I had a wood stove that started glowing low red (over heated, but it was cast iron) so I sprayed it with water to cool it, and that worked good. A good cast iron is pretty tough stuff, better than malleable at high temps I'm told. Ken Learn that steam burns, did you? Let me guess, you're an engineer. |
#43
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 1:43*pm, Jim Wilkins wrote:
On Dec 10, 2:00*pm, "Ken S. Tucker" wrote: wrote: In electronics, we have similiar problems, we usually solve using Al heat sinks, ... Ken- In my country we put the electronics on the other end of the airplane. we don't care. we just go to Congress and say 'you need to support the troops'. billion here, billion there. what, the electronics goes on the other end of the airplane??? ka-ching........ |
#44
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 1:00*pm, "Ken S. Tucker" wrote:
On Dec 10, 7:24 am, Jack Linthicum wrote: On Dec 10, 8:53 am, "Roger Conroy" wrote: "Bill Kambic" wrote in message .. . On Thu, 10 Dec 2009 02:57:36 -0800 (PST), Jack Linthicum wrote: snipped for brevity Or use the rocket launch technique and spray water across the take-off area. Probably less than optimal. *Large clouds of hot, salt water steam would be an annoyance (at a minimum) to the deck crew. *It would also be a highly corrosive material that could serious complicate maintenance of both ship and aircraft. Use of fresh water would likely be an excessive demand on the evaporators. The piping of cooling water suggested earlier would be a better idea. It would likely be cheaper that major modifications such as a "ski jump" and permit the continued use of the vertical capability of the aircraft. A water cooled heatsink built into a part of the deck designated for "hot" aircraft makes a lot of sense. You could have a place underneath to stash beer, like the old sub- mariners did. In electronics, we have similiar problems, we usually solve using Al heat sinks, fan air cooled, as the cheapest. Screw a few Al heat sinks to the bottom of the locations of the deck permited to take the heat and engage any fluid to cool it, even water if space is tight, yawn. Ken Pray tell, young Skywalker, what type of electronics have you designed that has a few thousands pounds of metal land on it, controlled by a navel aviatrix, blasting used JP4 and other noxious and profane gasses as high speeds and easily a thousand degrees of the Farenheits? I'm getting a case of beer and a lot of popcorn, this is going to be a good one. Note to Wiki: another cite for the 'Why do EE degrees have a BS in front of them....' |
#45
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The Melting Deck Plates Muddle - V-22 on LHD deck....
In article ,
frank wrote: Still not really durable enough to handle aircraft weight. Was less heat resistant than bottom portion. Think of it this way, bottom part gets really hot on reentry, shields top part. You could see some scorch marks on most of the post landing photos. Looks like little black scuff marks on foreward part near wing. Yeah, the blankets on the top top arent't as heat resistant as the tiles, but I don't think MV-22 or F-35B exhaust is quite as hot as hitting the atmosphere at 17,000mph. Wiki says one type of blanket (FRSI) is good to 700F and another (FIB) is good to 1200F. http://en.wikipedia.org/wiki/Space_S...tection_system Probably looks like a back to the drawing board moment. Oh, hey, anybody figure out we're landing on a carrier and we have some really high exhaust temps.... The thermal protection is available, they just need to figure out the durablity issue. I'm sure for a few billion, someone will be able to mix some nomex into the non-skit coating. John -- John Clear - http://www.clear-prop.org/ |
#46
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The Melting Deck Plates Muddle - V-22 on LHD deck....
In article
93ee764a-0400-499b-b519-37e47ef04416@v2 5g2000yqk.googlegroups.com, Richard wrote: On Dec 9, 11:23*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 3f72b032-2be2-4377-a180-01d7a81404fe@d2 1g2000yqn.googlegroups.com, *Mike wrote: StrategyPage.com December 2, 2009 The Melting Deck Plates Muddle by James Dunnigan Earlier this year, the U.S. Navy discovered that the heat from the MV-22's gas turbine engines, which blow their exhaust right on to the deck of the LHD while waiting to take off, caused high enough temperatures to the steel under the deck plates, to possibly warp the understructure. This was already a known potential problem with the new F-35B vertical takeoff jet fighter. So now the Navy has two hot new aircraft that require an innovative solution to the melting deck problem. The Navy also discovered that the exhaust heat problem varied in intensity between different classes of helicopter carriers (each with a different deck design.) The Navy is looking for a solution that will not require extensive modification of current carrier decks. This includes a lot of decks, both the eleven large carriers, and the ten smaller LHAs and LHDs. This is shaping up as another multi-billion dollar "oops" moment, as the melting deck problem was never brought up during the long development of either aircraft. Previously, the Harrier was the only aircraft to put serious amounts of heat on the carrier deck, but not enough to do damage. But when you compare the Harrier engine with those on the V-22 and F-35B, you can easily see that there is a lot more heat coming out of the two more recent aircraft. Someone should have done the math before it became a real problem. Use what NASA uses for the shuttle? Wouldn't cost that much at all Yeah except for not walking, parking, raining, hailing or dropping a wrench on the coating it would be great. Actually I was thinking of what they do at the launch pad during launch, not the tiles on the shuttle |
#47
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 11:58*pm, "Malcom \"Mal\" Reynolds" atlas-
wrote: In article 93ee764a-0400-499b-b519-37e47ef04416@v2 5g2000yqk.googlegroups.com, *Richard wrote: On Dec 9, 11:23*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 3f72b032-2be2-4377-a180-01d7a81404fe@d2 1g2000yqn.googlegroups.com, *Mike wrote: StrategyPage.com December 2, 2009 The Melting Deck Plates Muddle by James Dunnigan Earlier this year, the U.S. Navy discovered that the heat from the MV-22's gas turbine engines, which blow their exhaust right on to the deck of the LHD while waiting to take off, caused high enough temperatures to the steel under the deck plates, to possibly warp the understructure. This was already a known potential problem with the new F-35B vertical takeoff jet fighter. So now the Navy has two hot new aircraft that require an innovative solution to the melting deck problem. The Navy also discovered that the exhaust heat problem varied in intensity between different classes of helicopter carriers (each with a different deck design.) The Navy is looking for a solution that will not require extensive modification of current carrier decks. This includes a lot of decks, both the eleven large carriers, and the ten smaller LHAs and LHDs. This is shaping up as another multi-billion dollar "oops" moment, as the melting deck problem was never brought up during the long development of either aircraft. Previously, the Harrier was the only aircraft to put serious amounts of heat on the carrier deck, but not enough to do damage. But when you compare the Harrier engine with those on the V-22 and F-35B, you can easily see that there is a lot more heat coming out of the two more recent aircraft. Someone should have done the math before it became a real problem. Use what NASA uses for the shuttle? Wouldn't cost that much at all Yeah except for not walking, parking, raining, hailing or dropping a wrench on the coating it would be great. Actually I was thinking of what they do at the launch pad during launch, not the tiles on the shuttle Ever see photos of the pad, there is a large water tower near it. I think 3 seconds before launch, when engines start up, there is a water infusion into the bucket that thrust goes into. Think multiple streams of water. Sucker lights up, hits the water, massive steam and thrust go out the channels away from the launch pad. That's the big clouds that occur. Makes pad much more reusable. I think Shuttle was first system to use that, could be wrong. Makes entire complex much more reusable. If you can get some old Shuttle launch footage, that's one of the standard shots from NASA and main engine start. Awesome. Lots of plumbing though. |
#48
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 11, 2:42*am, frank wrote:
On Dec 10, 11:58*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 93ee764a-0400-499b-b519-37e47ef04416@v2 5g2000yqk.googlegroups.com, *Richard wrote: On Dec 9, 11:23*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 3f72b032-2be2-4377-a180-01d7a81404fe@d2 1g2000yqn.googlegroups.com, *Mike wrote: StrategyPage.com December 2, 2009 The Melting Deck Plates Muddle by James Dunnigan Earlier this year, the U.S. Navy discovered that the heat from the MV-22's gas turbine engines, which blow their exhaust right on to the deck of the LHD while waiting to take off, caused high enough temperatures to the steel under the deck plates, to possibly warp the understructure. This was already a known potential problem with the new F-35B vertical takeoff jet fighter. So now the Navy has two hot new aircraft that require an innovative solution to the melting deck problem. The Navy also discovered that the exhaust heat problem varied in intensity between different classes of helicopter carriers (each with a different deck design.) The Navy is looking for a solution that will not require extensive modification of current carrier decks. This includes a lot of decks, both the eleven large carriers, and the ten smaller LHAs and LHDs.. This is shaping up as another multi-billion dollar "oops" moment, as the melting deck problem was never brought up during the long development of either aircraft. Previously, the Harrier was the only aircraft to put serious amounts of heat on the carrier deck, but not enough to do damage. But when you compare the Harrier engine with those on the V-22 and F-35B, you can easily see that there is a lot more heat coming out of the two more recent aircraft. Someone should have done the math before it became a real problem. Use what NASA uses for the shuttle? Wouldn't cost that much at all Yeah except for not walking, parking, raining, hailing or dropping a wrench on the coating it would be great. Actually I was thinking of what they do at the launch pad during launch, not the tiles on the shuttle Ever see photos of the pad, there is a large water tower near it. I think 3 seconds before launch, when engines start up, there is a water infusion into the bucket that thrust goes into. Think multiple streams of water. Sucker lights up, hits the water, massive steam and thrust go out the channels away from the launch pad. That's the big clouds that occur. Makes pad much more reusable. I think Shuttle was first system to use that, could be wrong. Makes entire complex much more reusable. If you can get some old Shuttle launch footage, that's one of the standard shots from NASA and main engine start. Awesome. Lots of plumbing though. One of the professed goals of the system is sound suppression. That's one of the events the crowds come to the launches for---that magnificent roar like the end of the world. |
#49
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 10, 4:09 pm, frank wrote:
On Dec 10, 1:00 pm, "Ken S. Tucker" wrote: On Dec 10, 7:24 am, Jack Linthicum wrote: On Dec 10, 8:53 am, "Roger Conroy" wrote: "Bill Kambic" wrote in message .. . On Thu, 10 Dec 2009 02:57:36 -0800 (PST), Jack Linthicum wrote: snipped for brevity Or use the rocket launch technique and spray water across the take-off area. Probably less than optimal. Large clouds of hot, salt water steam would be an annoyance (at a minimum) to the deck crew. It would also be a highly corrosive material that could serious complicate maintenance of both ship and aircraft. Use of fresh water would likely be an excessive demand on the evaporators. The piping of cooling water suggested earlier would be a better idea. It would likely be cheaper that major modifications such as a "ski jump" and permit the continued use of the vertical capability of the aircraft. A water cooled heatsink built into a part of the deck designated for "hot" aircraft makes a lot of sense. You could have a place underneath to stash beer, like the old sub- mariners did. In electronics, we have similiar problems, we usually solve using Al heat sinks, fan air cooled, as the cheapest. Screw a few Al heat sinks to the bottom of the locations of the deck permited to take the heat and engage any fluid to cool it, even water if space is tight, yawn. Ken Pray tell, young Skywalker, what type of electronics have you designed that has a few thousands pounds of metal land on it, controlled by a navel aviatrix, blasting used JP4 and other noxious and profane gasses as high speeds and easily a thousand degrees of the Farenheits? I'm getting a case of beer and a lot of popcorn, this is going to be a good one. Note to Wiki: another cite for the 'Why do EE degrees have a BS in front of them....' Frank, note you've replied to me 3 times, somewhat sarcastically on a topic that is borderline boring for most, but I own a patent on a 'new and improved' woodstove, so I have an extra interest and specialized knowledge on the subject, so I find the problem intriguing, About "degrees", and "diploma's" mine are buried somewhere in archives, rusting away. Ken |
#50
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The Melting Deck Plates Muddle - V-22 on LHD deck....
In article
, frank wrote: Actually I was thinking of what they do at the launch pad during launch, not the tiles on the shuttle Ever see photos of the pad, there is a large water tower near it. I think 3 seconds before launch, when engines start up, there is a water infusion into the bucket that thrust goes into. Think multiple streams of water. Sucker lights up, hits the water, massive steam and thrust go out the channels away from the launch pad. That's the big clouds that occur. Makes pad much more reusable. I think Shuttle was first system to use that, could be wrong. Makes entire complex much more reusable. Nope -- Massive water infusion was used on the Saturn V, IB, Ic, etc. It helped cool the exhaust gases that impinged on the deflectors. A direct hit from a rocket motor exhaust of that size would make short work of any material you could use. As it was, there was still plenty od flame damage to go around. If you can get some old Shuttle launch footage, that's one of the standard shots from NASA and main engine start. Awesome. Lots of plumbing though. -- Remove _'s from email address to talk to me. |
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