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#61
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 11, 5:08 pm, Dan wrote:
Ken S. Tucker wrote: 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 om... 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 Great, now post a link to that patent. Dan, U.S. Air Force, retired Patents are those legal things that get tossed into archives, to be forgotten about, but your request is interesting, do they put that online |?| I'll check. C-dyn is old school and for transactions use snail-mail contracts, for example today we received an order in the mail via snail, from Vermont, that was posted Nov.30., for customized electro gEAR. I'm thinking of complaining about the snail-mail speed. Recently, I received 1st class Air-mail products from Indiana, it took 10 (f**king) days to hit our box. If anyone is interested in an experiment, I'll send you an Xmas card, we can do addresses via email, but mine is hEAR, http://www.trak4.com/earco/index.html so mail us a card. Love & Kisses Lynne & Ken |
#62
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The Melting Deck Plates Muddle - V-22 on LHD deck....
Ken S. Tucker ha scritto:
Patents are those legal things that get tossed into archives, to be forgotten about, but your request is interesting, do they put that online |?| I'll check. with goggle patents and uspto.gov all whose suffice is that you post the patent number Best regards from Italy, Dott. Piergiorgio. |
#63
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 11, 8:21*pm, Strobe wrote:
On Thu, 10 Dec 2009 23:42:41 -0800 (PST), 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. Imagine being the pilot taking off through all that steam. Or landing, when visibility suddenly drops to zero as you come over the pad. Now imagine again, this time remembering that there's solid lumps of ship only a few yards from your rotors. . . A strong refractory coating seems much more attractive. With a thirty knot wind over the bow? |
#64
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just curious The Melting Deck Plates
ONR is looking for thermal management technologies that can keep the
deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...amend0001.ashx With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. |
#65
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just curious The Melting Deck Plates
On Dec 12, 11:43*am, D Wright wrote:
ONR is looking for thermal management technologies that can keep the deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...ements/BAA/09-... With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? *It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. 3-10 feet in diameter, just like the spec said. |
#66
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just curious The Melting Deck Plates
Jack Linthicum wrote:
On Dec 12, 11:43 am, D Wright wrote: ONR is looking for thermal management technologies that can keep the deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...ements/BAA/09-... With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. 3-10 feet in diameter, just like the spec said. Is the 'spec suggesting temps of 1,000+ F are of no consequence outside of a ten foot circle? Where is residual heat in the equation? What if the ten foot circle moves? |
#67
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just curious The Melting Deck Plates
On Dec 12, 12:30*pm, D Wright wrote:
Jack Linthicum wrote: On Dec 12, 11:43 am, D Wright wrote: ONR is looking for thermal management technologies that can keep the deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...ements/BAA/09-.... With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? *It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. 3-10 feet in diameter, just like the spec said. Is the 'spec suggesting temps of 1,000+ F are of no consequence outside of a ten foot circle? *Where is residual heat in the equation? *What if the ten foot circle moves? Then the Osprey is moving |
#68
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just curious The Melting Deck Plates
On Dec 12, 6:30*pm, D Wright wrote:
Jack Linthicum wrote: On Dec 12, 11:43 am, D Wright wrote: ONR is looking for thermal management technologies that can keep the deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...ements/BAA/09-.... With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? *It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. 3-10 feet in diameter, just like the spec said. Is the 'spec suggesting temps of 1,000+ F are of no consequence outside of a ten foot circle? *Where is residual heat in the equation? *What if the ten foot circle moves? It's the *exhaust" that is in the 1,000-1,700 F range. The information may be relevant since radiated heat adds to convection. The only useful information in that whole piece would be that temporary deformations occur in the elastic domain, so it's really not as severe nor urgent as would be a melting deck dripping in the ocean, thank god. |
#69
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 12, 12:26 am, "dott.Piergiorgio"
wrote: Ken S. Tucker ha scritto: Patents are those legal things that get tossed into archives, to be forgotten about, but your request is interesting, do they put that online |?| I'll check. with goggle patents and uspto.gov all whose suffice is that you post the patent number Best regards from Italy, Dott. Piergiorgio. Ok, found it, Canadian Patent # 1 241 883 issued Sep 13 1988. Ken |
#70
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just curious The Melting Deck Plates
On Dec 12, 2:02*pm, Daniel wrote:
On Dec 12, 6:30*pm, D Wright wrote: Jack Linthicum wrote: On Dec 12, 11:43 am, D Wright wrote: ONR is looking for thermal management technologies that can keep the deck surface temperature below 300ºF when exposed to MV-22 exhaust plumes for 90 minutes before takeoff, and F-35B exhaust plumes for 2 minutes when landing. And cooling the deck is not enough - any solution has to be compatible with the deck's non-skid coating. It also has to be affordable and capable of being installed below deck or retrofitted above deck. Tall order. “Structural Evaluation of an LHD-Class Amphibious Ship Flight Deck Subjected to Exhaust Gas Heat from a MV-22 Osprey Aircraft,” they note that deck buckling occurs at a temperature of 160oF to 170oF. Where does the 300oF limit originate? Response: The 300 degree F is derived from the temperature limit of the tires on aircraft. How concentrated is the heat flux, how large an area is involved in the 24,000BTU/min heating? I have had difficulty getting any numbers and the information heat flux given in the BAA did not include an area component. Response: A range of 3-foot to 10-foot diameter is suggested. Max exhaust temperature anticipated? Response: This is tightly controlled. A range of max temperatures could be 1000– 1700 deg. F. http://www.onr.navy.mil/~/media/File...ements/BAA/09-... With hot aircraft tires being an additional concern, what about the impact on the feet of the flight deck crew, refueling hoses, "mule" tires, etc? *It seems like this heat issue may take on the dimensions of a "systemic" problem. It's just the nature of naval air ops that once an aircraft (weapons system) is established, it will become heaver, more powerful, and the tempo of operations will increase. 3-10 feet in diameter, just like the spec said. Is the 'spec suggesting temps of 1,000+ F are of no consequence outside of a ten foot circle? *Where is residual heat in the equation? *What if the ten foot circle moves? It's the *exhaust" that is in the 1,000-1,700 F range. The information may be relevant since radiated heat adds to convection. The only useful information in that whole piece would be that temporary deformations occur in the elastic domain, so it's really not as severe nor urgent as would be a melting deck dripping in the ocean, thank god. The paper seems to be worried about some non-skid deck surfacing. |
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