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.