Probably something better to keep kinematic performance.
2623031 - ВОЗДУХОЗАБОРНИК САМОЛЕТА - иллюстрации (findpatent.ru)
View attachment 67449View attachment 67450View attachment 67451View attachment 67448
- There are partial S-ducts as demonstrated on the patent itself. Meaning the fan blades are not completely exposed but partially which is still regarded as an RCS reducing feature.
- RAM is applied in the inlet so that is regarded as another RCS reducing feature.
- Patent and image shows radar blockers to reflect radio waves away from radar source and covering fan blades so that is another RCS reducing feature.
- There is an anti-radar grading installed inside the air channel and guess what, that is another RCS reducing feature.
- Fan blades are made of composite materials which again is an RCS reducing feature.
- Image of inlet vanes along with patent which are behind the blades are seen as being designed a particular way to lower RCS and being made of composites as well, so another RCS reducing feature.
Its not hard having access to a anechoic chamber using Ufimtsev's equations, having S-ducts is not all that authentic either when it was present on their Su-47 but decided to trade stealth for stealth and aerodynamic performance. I can't compare which is the more RCS reducing design and by how much since I don't have a billion dollar radar chamber but that is why I try to ignore most run of the mill internet enthusiasts.
My brother from another mother has arrived .
I have a slide of Radar blocker cum IGV for MiG-29 . I will look for it.
There is an IGV, the device S plus another EGV in that air intake. Then there's the first stage fan of AL-41F 1 which itself is coated heavily with ram.
Unlike the F-22 and F-35's intakes where there is a huge pressure drop due to the pronounced s curve , there's little pressure drop in this inlet duct . Then there is more pressure recovery possible here.
Plus the entire duct acts as a RAS unlike the F-22 intakes and ducts. After that, there is extensive liberal treatment with RAM .
People don't realise the quantum of effort that has gone into designing the intakes and the EGV , Device S and IGV . Together with Item 30, it's acts as a single unit.
So whenever posters say the engine is exposed, I just give them a wide berth. Ignorance is bliss.