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#71
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Sat, 12 Dec 2009 02:46:28 -0800 (PST), Jack Linthicum
wrote: On Dec 11, 8:21Â*pm, Strobe wrote: On Thu, 10 Dec 2009 23:42:41 -0800 (PST), frank wrote: On Dec 10, 11:58Â*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 93ee764a-0400-499b-b519-37e47ef04416@v2 5g2000yqk.googlegroups.com, Â*Richard wrote: On Dec 9, 11:23Â*pm, "Malcom \"Mal\" Reynolds" atlas- wrote: In article 3f72b032-2be2-4377-a180-01d7a81404fe@d2 1g2000yqn.googlegroups.com, Â*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? Imagine that 30 kt wind has to work against both the rotor down draft and the turbine exhaust (how many knots?) to remove the steam. Imagine betting your life that the headwind wins all the time. |
#72
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 13, 1:03*am, Strobe wrote:
On Sat, 12 Dec 2009 02:46:28 -0800 (PST), Jack Linthicum wrote: 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? Imagine that 30 kt wind has to work against both the rotor down draft and the turbine exhaust (how many knots?) to remove the steam. Imagine betting your life that the headwind wins all the time. Carriers use 30kt into the wind for launching (although most modern Naval AC can launch in harbor.) An LHP, launching or especially landing VTOL AC is safer dealing with less wind across the deck. Unless of course they are performing a rolling take-off. BB |
#73
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 12, 12:31 pm, "Ken S. Tucker" wrote:
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 Found some data online, http://brevets-patents.ic.gc.ca/opic...ch#View_Images Ken |
#74
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 11, 5:06*pm, Jack Linthicum
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. I've got this conversation at ONR in my head... "We've got a problem. Those Ospreys are ****ing up the decks." "Define '****ing up.'" "Well, here's the problem. [snip detailed description and analysis]" "Are you serious? They never accounted for that?" "No sir." "Well...what do we have that can take that kind of heat?" "Nothing that I know of, sir." "Well...damn...look, SOMEONE's gotta have something. Put out an RFI and keep your fingers crossed." |
#75
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The Melting Deck Plates Muddle - V-22 on LHD deck....
Ken S. Tucker wrote:
On Dec 12, 12:31 pm, "Ken S. Tucker" wrote: 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 Found some data online, http://brevets-patents.ic.gc.ca/opic...ch#View_Images Ken OK, I grant you were honest this time. Dan, U.S. Air Force, retired |
#76
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 13, 1:15 pm, Dan wrote:
Ken S. Tucker wrote: On Dec 12, 12:31 pm, "Ken S. Tucker" wrote: 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 Found some data online, http://brevets-patents.ic.gc.ca/opic...t/1241883/summ... Ken OK, I grant you were honest this time. Dan, U.S. Air Force, retired How would you know? My real name could be Danelda Dip****z, masquerading as that very handsome, captain of industry, the one and only Ken Tucker who women flock to. Actually it was fun to find the patent online, but it's hardly sumfink to brag about, just an honest interest in practical thermodynamics. Ken |
#77
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The Melting Deck Plates Muddle - V-22 on LHD deck....
The Melting Deck Plates Muddle 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. What about clamshell deflectors for the hot exhausts? During warmup before takeoff the clamshell halves deflect the hot exhaust forward and rearward, away from the deck. At the moment of takeoff the clamshell doors close partally to reduce the deflection angle (which will provide some vertical thrust and side thrust) or move out of the way altogether to allow the hot exhaust to shoot the deck. For landing, as the aircraft comes close to deck the clamshells are partially closed, again to deflect the hot exhausts from blowing directly on the deck. How this will affect controllability will need to be tested for practicality. On landing the clamshell doors will be in full deflection mode (Fwd and Rearwd) to keep the hot gasses awway from the deck. |
#78
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 14, 7:02*am, PaPa Peng wrote:
The Melting Deck Plates Muddle 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. What about clamshell deflectors for the hot exhausts? During warmup before takeoff the clamshell halves deflect the hot exhaust forward and rearward, away from the deck. *At the moment of takeoff the clamshell doors close partally to reduce the deflection angle (which will provide some vertical thrust and side thrust) or move out of the way altogether to allow the hot exhaust to shoot the deck. For landing, *as the aircraft comes close to deck the clamshells are partially *closed, again to deflect the hot exhausts from blowing directly on the deck. *How this will affect controllability will need to be tested for practicality. *On landing the clamshell doors will be in full deflection mode (Fwd and Rearwd) to keep the hot gasses awway from the deck. That's what I've been thinking, at least for the Ospreys. The solution ought to be on the airframe, not on the deck, because no matter where the bird goes, the hot exhaust will be an issue, and not every landing platform will be treated in the same way. |
#79
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The Melting Deck Plates Muddle - V-22 on LHD deck....
On Dec 14, 10:44*am, Typhoon502 wrote:
On Dec 14, 7:02*am, PaPa Peng wrote: The Melting Deck Plates Muddle 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. What about clamshell deflectors for the hot exhausts? During warmup before takeoff the clamshell halves deflect the hot exhaust forward and rearward, away from the deck. *At the moment of takeoff the clamshell doors close partally to reduce the deflection angle (which will provide some vertical thrust and side thrust) or move out of the way altogether to allow the hot exhaust to shoot the deck. For landing, *as the aircraft comes close to deck the clamshells are partially *closed, again to deflect the hot exhausts from blowing directly on the deck. *How this will affect controllability will need to be tested for practicality. *On landing the clamshell doors will be in full deflection mode (Fwd and Rearwd) to keep the hot gasses awway from the deck. That's what I've been thinking, at least for the Ospreys. The solution ought to be on the airframe, not on the deck, because no matter where the bird goes, the hot exhaust will be an issue, and not every landing platform will be treated in the same way. Weight on the aircraft is one of the Osprey's problems. Better to make a deck covering that does the job without burdening the aircraft. |
#80
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The Melting Deck Plates Muddle - V-22 on LHD deck....
Jack Linthicum wrote:
On Dec 14, 10:44 am, Typhoon502 wrote: On Dec 14, 7:02 am, PaPa Peng wrote: The Melting Deck Plates Muddle 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. What about clamshell deflectors for the hot exhausts? During warmup before takeoff the clamshell halves deflect the hot exhaust forward and rearward, away from the deck. At the moment of takeoff the clamshell doors close partally to reduce the deflection angle (which will provide some vertical thrust and side thrust) or move out of the way altogether to allow the hot exhaust to shoot the deck. For landing, as the aircraft comes close to deck the clamshells are partially closed, again to deflect the hot exhausts from blowing directly on the deck. How this will affect controllability will need to be tested for practicality. On landing the clamshell doors will be in full deflection mode (Fwd and Rearwd) to keep the hot gasses awway from the deck. That's what I've been thinking, at least for the Ospreys. The solution ought to be on the airframe, not on the deck, because no matter where the bird goes, the hot exhaust will be an issue, and not every landing platform will be treated in the same way. Weight on the aircraft is one of the Osprey's problems. Better to make a deck covering that does the job without burdening the aircraft. Yes. Anything added to the aircraft subtracts payload. It also adds another failure mode. |
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