Do Aircraft carriers have any Aero design onsiderations?

[Piotrsko]

Originally Posted by j-c-c

On US carriers the deck is extremely flat in the takeoff portion IMO.
My thinking a carrier in many ways might operate as an inverted flat bottom car with a front splitter, optimizing smooth/proper air flow for aircraft on the deck, but my question centers around, is that intentional?
Maybe not, since the "sky Jump" carrier decks would have I suspect lousy aero features,

Have you actually seen or been on an operating carrier deck? Except forward of the catapult blast wall there's stuff everywhere. If they aren't launching even the catapault area has things belayed upon it. Aero isn't a prime requirement nor is smooth airflow while launching into rough weather.

[j-c-c]

I think my comment/question here went over your head,
I'm not going to bother to repeat myself. you may want to review all of what I read carefully.

[aerohead]

* the 'length' of the boat is probably the most important, as, while
'at sea' it's subject to 'pitching', with the angle of attack of the oncoming air, varying continuously with the height and separation frequency of the swells.
* depending on 'current' density altitude, each aircraft can be configured for optimum 'lift/drag' for takeoff and landing.
8) steam catapult launch systems guarantee that the plane will leave the deck at above 'stall' conditions, and power-to-weight, and rate of climb performance, specified by th NAVY, as a condition of purchase from the contractor, guarantees the under the worst-case-scenario, the the planes will make a successful takeoff.
9) the redundancy in catch-cables, 'usually' guarantees a successful landing.
10) the body of historical meteorological data in hand, allows 'known-knowns' for handling all take-offs and landings.
11) the launch deck will be 'submerged' in a turbulent boundary-layer, so any 'laminar flow' will exist only at some elevation above it, based on the distance from the 'bow' of the deck; and will be 'thickest' as the aircraft leaves the blast-diverters at initiation of launch.
12) looking at the leading edge of the USS Gerald R. Ford, there doesn't appear to be 'ANYTHING' done to address aerodynamics.

[Hersbird]

Originally Posted by freebeard

Compared to what? They have the advantage over land based runways in that they can orient into the wind.

And make a 40mph headwind all by themselves. With an average natural wind speed of 18 mph off shore, it's pretty easy to make a 50+ mph steady headwind down the delck. That's not the normal goal, I think 30 mph is what they try and maintain, but they don't want crosswinds. Sometimes they would go downwind if the natural wind was over 50 mph, turn and go downwind at 20 to reduce the operational wind on the deck back to a more managed 30.

We Sometimes did a picnic on the flight deck called a "steel beach picnic". They could always get just a perfect, cooling, light breeze on the deck by adjusting speed and direction.

[freebeard]

I think my comment/question here went over your head,
I'm not going to bother to repeat myself. you may want to review all of what I read carefully.

"...but my question centers around, is that intentional?"

Intent is hard to prove.

[j-c-c]

Originally Posted by aerohead

*
11) the launch deck will be 'submerged' in a turbulent boundary-layer, so any 'laminar flow' will exist only at some elevation above it, based on the distance from the 'bow' of the deck; and will be 'thickest' as the aircraft leaves the blast-diverters at initiation of launch.

This one addresses my concerns best. I suspect the aero on a carrier deck that piques my interest in this thread is the area only upon aircraft lift off and until being clear of any potential aero bow wake. Ground effect will play a part when that lift off is achieved. An aircraft at relativity low speeds slightly above stall speed would seem to very susceptible to abrupt wind changes/currents when nearing the end of deck, even when airborne.

12) looking at the leading edge of the USS Gerald R. Ford, there doesn't appear to be 'ANYTHING' done to address aerodynamics.

I agree, but not observing anything does not by itself indicate nothing intentionally aero was not addressed, and hence my original question here.

A triple negative?

[freebeard]

I suspect the aero on a carrier deck that piques my interest in this thread is the area only upon aircraft lift off and until being clear of any potential aero bow wake.

I'll defer to Piotrsko on this, but I don't think the aircraft lift off, they fall off.

[j-c-c]

Whatever.

[aerohead]

Originally Posted by j-c-c

I agree, but not observing anything does not by itself indicate nothing intentionally aero was not addressed, and hence my original question here.

A triple negative?

1) I read a paper by the Office of Naval Affairs on aircraft carrier design.
The whole process is compromise between competing aspects of shipborne activities and contingencies.
2) Between the time that a design is 'frozen', construction begins, and the time when construction is completed, 'carrier compatible; aircraft may have evolved, especially with STOL/VTOL designs, which don't need as much 'runway' ( some need 'none', and takeoff velocities.
3) In 'ALL' design scenarios, the carrier must satisfy all aircraft parameters for takeoff and landing, with only one propellor in service ( as a twin-engine commercial airliner must be able to fly effectively with one 'dead' engine).
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The only other thing I saw was, in regard to a photo of the USS Kittyhawk, with a departing F-18 fighter just clearing the leading edge of its flight deck.
Both runways on this carrier have 1/4-round, leading-edge fairings, as you'd see on the bottom of an open-test-section wind tunnel nozzle at the test-section's entrance, which prevents vena-contracta entry loss formation and the attendant turbulence formation.
The 1/4-round fairing would not prevent boundary-layer buildup downstream of the 'nose', but it would mitigate 'flow separation' right at the 'end' of the runway.
Some design group clearly was thinking of the ramifications to airflow in the absence of the edge radii.

[j-c-c]

Now we are addressing the question.

So that begs the question, why don't all modern recent carriers have a 1/4 round leading edge?

Additionally, many WW2 and pre War carriers were adaptations of cruisers and battle ships, which had basically a flat flight deck extended above the main superstructure, allowing IMO significant air to flow under the flight deck and not redirect significant wake airflow onto the deck, so they likely weren't faced with the issue i am originally asking about.
Interesting about the one engine concern, which only makes sense.