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How is the aircraft skin around the engine bay in the F-22 cooled?

As in the F-35, there are scoops below the wings, which provide ram air around the engine bay, but you don't see any scoop around in the F-22 for the same purpose.

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Location of F-35 scoops according to codeonemagazine.com

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    $\begingroup$ Please provide details as to why you think there would be a cooling issue (given that the engine is a turbofan). $\endgroup$ – ymb1 Jan 31 '19 at 13:02
  • $\begingroup$ As in F 35 there are scoop below the wings which provide ram air around the engine bay, but you don't see any scoop around in the F 22 for the same purpose $\endgroup$ – Ashish Bhatt Jan 31 '19 at 15:55
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    $\begingroup$ It's now clearer; I've moved your comment into the question, and added a photo that explains the F-35 ventilation scoops. $\endgroup$ – ymb1 Jan 31 '19 at 16:22
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The exact details of the F22 are classified. But the more likely scenario is the engine has a cold bypass air gap between the afterburner inner wall and its exterior shroud. From all the close-up shot of its nozzle, the thrust vectoring nozzle and the emergency arrestment hook fairing is lined with some sort of refractory materials and need no special cooling and the serrated nozzle fairings on either side of the nozzle seem airtight and have no place for a cooling air stream outlet. Plus, we see no scoop on the front of the aircraft as an inlet for engine cooling, and the scoop, should it exist, must be quite large. I say this is the most likely scenario because it's the least heavy and complex solution to engine cooling. And let us do not forget small cavities with a diameter in the range of millimeters is the most effective radar wave reflector/scatterer.

A less likely scenario is the engine is cooled by fuel, just like the avionics, the radar and the AC for the pilot. The fuel is then cooled first by the sheer amount of wing area as a radiator and second by a pair of hidden air-cooled fuel cooler. (I won't tell you where :))

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  • $\begingroup$ It's not about the engine cooling, if you want the aircraft to be more stealthy the area around engine also be cooled. There are 6 diamond shaped opening in the rear bottom fuselage of the aircraft are they meant to provide air into engine bay $\endgroup$ – Ashish Bhatt Jan 31 '19 at 15:57
  • $\begingroup$ @AshishBhatt can you include the link to your claim in your original question? $\endgroup$ – Meatball Princess Jan 31 '19 at 16:42
  • $\begingroup$ @AshishBhatt I'm just speaking from my memory. I don't think there is an authoritative illustration of the underside of the Raptor. But from what I know that seems to be outlets rather than inlets and they seem to be the outlets of the Primary Heat Exchanger, used to cool down bleed air to provide air to pilot. $\endgroup$ – Meatball Princess Jan 31 '19 at 17:32
  • $\begingroup$ pinterest.com/pin/524528687823913529 this link shows a cutaway of F 22 clearly the heat exchanger inlet and outlet are on the top, APU inlet and outlet is also on the top, ECS inlet and outlet are towards the front. $\endgroup$ – Ashish Bhatt Feb 1 '19 at 2:33
  • $\begingroup$ goo.gl/images/vEVwFk In this link if you see there are 6 openings on the bottom are they meant for bay cooling? $\endgroup$ – Ashish Bhatt Feb 1 '19 at 2:37

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