First VIDEO is here

VIDEO URL:

This video is realy, Because I stayed here, I stayed same place yesterday

you can see J- 20 at 40 second of this Video

http://www.tudou.com/programs/view/VDrpLi8EER0/

Thanks for that video and listen carefully, last seconds of the J-20 high speed run test when engines are set to idle, they are “singing” very well like Al-31 engines…:) Compare with this video.

http://www.youtube.com/watch?v=ZwAHopfhGWg

Well, i’m saying they are just designing the thing without any SC requirement, f-22/pakfa intakes are larger, not just because it cross area, but because the real area is increased due the sweept of their leading edge intakes, they are actually much larger than they look.

Let’s remember the JSF concept never required any SC capability, and early JSF concepts had basically the same J-20 basic configuration, boxy fuselage with canard-delta layout.

Yes they are taller, but it cross area, and real area are still small IMVHO, of course.

I don’t know if the DSI concept is compatible with SC requirement, since all Boeing’s F/A-XX concepts have conventional intakes without DSI.

This is of course what I think,I know we don’t really know a lot about this plane, and I know that on this I may be wrong, so is just a humble opinion.

It could be well the case that I missed something important, but did Chinese really claimed the J-XX was designed without SC requirements? All I can derive from pictures so far is the J-20 inlet system will not be good Mach>2 performer as it is not variable one, but features a cost-saving and probably RCS helping solution, a simple boundary layer diverter or “bump” not ideal for the whole mach range though. The DSI inlet is designed for a specified supersonic Mach number (e.g. M1.6) where it performs let say optimal minimizing airflow losses in the duct allowing the J-20 to fly supersonic. But I think the ability flying sustained supersonic or supercruising (e.g. M1.6) comes from engines itself and not from the presence or absence of the DSI in general. Of course, not saying the inlet system doesnt play a role there, but I would not simply assume that the bigger the inlets are then better the supercruise performance is.
When looking at the J-20 intakes it also occured to me that perhaps those
will be more susceptible to stalls during high-angle-of-attack maneuvers when compared to the T-50 intakes due to the fact you mentioned above.

The sweept angle of the intake is negative, like the 35’s one, so unlike the T-50/F-22 intake, the intake’s area is definitivelly smaller, add to this the diverter, and you actually get a even smaller intake area.

IMVHO, this plane is not designed for SC, of course i may be wrong.

Disagree with opinion that J-20 intakes are too small. I think intakes are adequate to provide enough mass flow to engines in any flight regime, whether low speeds high AOA or high Mach numbers. Otherwise you are indirectly saying that Chinese engineers screwed up doing simple calculations of equation of continuity. 🙂 After all that when seeing the J-20 I wouldnt dare to say it will be a bad supercruiser bcs it could also be the best one.
These intakes seem to be narrowed in their width but are taller due to shaping front fuselage “chines“, compare them with diamond like F-22 intakes.

wondering whether the wing geometry is modeled properly. There seems to be a wing trailing edge perpendicular to the a/c axis, am I right?

what the word “overengineered” means, from wikipedia…:rolleyes:
Overengineering (or over-engineering) is when a product is more robust or complicated than necessary for its application, either (charitably) to ensure sufficient factor of safety, sufficient functionality, or due to design errors. Overengineering is desirable when safety or performance on a particular criterion is critical, or when broad functionality is required, but it is generally criticized from the point of view of value engineering as wasteful, and as a design philosophy, overcomplexity is the opposite of the less is more school of thought (and hence a violation of the KISS principle and parsimony).

Overengineering generally occurs in high-end products or specialized market criteria, and takes various forms. In one form, products are overbuilt, and have performance far in excess of needs (a family sedan that can drive at 300 km/h, or a home video cassette recorder with a projected lifespan of 100 years), and hence are more expensive, bulkier, and heavier than necessary. Alternatively, they may be overcomplicated – the design may be far more complicated than is necessary for its use, such as a modern text editor asking whether files should be saved in ASCII or EBCDIC format. Overcomplexity reduces usability of the product by the end user, and can decrease productivity of the design team due to the need to build and maintain all the features.

A related issue is market segmentation – making different products for different market segments. In this context, a particular product may be more or less suited for a particular market segment, and may be over- or under- engineered relative to an application.

To me still the F-22 fits the best….

Enlarged views of previous pictures side by side:

any chance the J-20 uses forward swept wing like the russian S-37 (Su-47) Berkut?

found this article …
http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3A27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3A5d5351e5-8a5f-4073-9428-c3129cabdf6a&plckScript=blogScript&plckElementId=blogDest

Rust and Stealth
………….

Lessons learned have been applied, the GAO saying:

“The F-35 program is mitigating corrosion risk associated with conductive gap filler and paint by using a gap filler that is less galvanically dissimilar from aluminum, an alternative to the conductive paint, a design with fewer seams that require gap filler, and more representative verification and qualification testing. Many of the F-22’s corrosion problems were linked to problems with gap filler materials and paint. The F-35 drainage design is significantly improved with more, adequately sized drain holes. Drain holes in the F-22 were found to be too small to enable good water drainage.”