v**e
发帖数: 8422 | | v**e
发帖数: 8422 | | d*****l
发帖数: 8441 | 3 First, to achieve smooth airflow with desirable
parameters at the entry to the engine’
s fan, the J-20’s designers have to
make the air intakes rather long. This was
an important consideration at design stage.
Second, they also needed to make
the air channel S-shaped, so as to hide
the fan blades from the radio waves emitted
by enemy radars. The latter is needed
for a lower visibility of the airplane. It
is worth to notice that the J-20’s air intakes
resemble those first tried on the Lockheed
Martin F-35 Lightning II. This gives move
ground to assert that the J-20 is optimized
for supersonic regimes and supercruise,
much like the F-35.
Third, let us make distribution diagram
for the airplane’s cross section along
the J-20’s fuselage centerline. We need to
take account of the thickness of the wing,
canards and tailplanes. The diagram is
very smooth, — exceptionally smooth! It
comes without a peak, running smoothly
at approximately the same height from
the tops of the air intakes all the way to
the engine nozzles.
This seems to be the main thing for
the Chengdu designers. Apparently, they
wanted to make the airplane’s equivalent
body of rotation as narrow as possible.
And they needed to make provision
for internal carriage of weapons, which
is a characteristic feature for fifth generation
fighters. In actual fact, the J-20 has
much smoother cross section distribution
diagram than the F-22A Raptor, the F-35
Lightning II and the Sukhoi T-50 (PAK FA FGFA). Apparently, it required
quite an effort
from Chengdu designers and so made
them go for compromises on other things.
Should the designers from Chendgu
have made it “classic”, they would not
have moved the wing all the way towards
the engine nozzles. But they did because was the only effective way to make
the airplane
as narrow as possible, with the need
for big air intakes, air-supply channels and
internal weapons bays.
Again, this is the main thing about
the J-20 design, and it sets it apart from
all other known next-generation fighters.
Other designs have “peaks” in some
60–70% down the way from the fuselage
nose tip to the engine nozzles.
A smooth cross section distribution diagram
is important for transonic drag. Supersonic
aircraft are being designed
in accordance with so-called “area ruling”.
For high Mach numbers (M>2)
the distribution diagram is not so important
as for transonic regimes, M=1…1.5. seems the Chinese designers optimized
their new jet for transonic regimes and
moderate supersonic speeds.
Our impression from the J-20 is that it
is an uncompromised airplane for supercruse,
for flying at moderate supersonic
speeds corresponding to Mach M=1.3–
1.6. Such speeds can be achieved without
afterburning. Surely, the J-20 can accelerate
to M=2 and faster, but this would
require engaging afterburners. In turn,
the fuel burn will go high, lowering operational
range of the aircraft and enlarging
its heat signature.
In our view the Chinese designers optimized
their new jet for M=1.3–1.6. | d*****l
发帖数: 8441 | 4 Summary: 土共的机体设计特意取向细长，机体截面从前往后刻意做到平滑、无过大截面峰值：目标超巡和跨音速段性能最优，超巡1.3到1.6马赫无需加力；超到2.0马赫以上需要加力。
【在 d*****l 的大作中提到】
: First, to achieve smooth airflow with desirable
: parameters at the entry to the engine’
: s fan, the J-20’s designers have to
: make the air intakes rather long. This was
: an important consideration at design stage.
: Second, they also needed to make
: the air channel S-shaped, so as to hide
: the fan blades from the radio waves emitted
: by enemy radars. The latter is needed
: for a lower visibility of the airplane. It
| y****t
发帖数: 9189 | 5 缺最牛的黑桃A啊。
【在 v**e 的大作中提到】
: 杂志里面一张图
| h*i
发帖数: 3446 | 6 上面的转贴没贴文章最后的结论：J20是用来反舰的，是为美国海军定身制作的。
...the J-20 is a missile launching platform able to evade enemy
interceptors by high cruise speed. The J-20 may prove a good interceptor, —
very possibly. But its main task seems to be anti-shipping: firing missiles
at enemy warships while denying their air defense cover.
....
Since the memorable Battle of Hampton, the North Americans never
lose at sea, and now their cheese boxes（泛指美军水面舰船，由Monitor号铁甲舰
来）sale when and where they want. China prepares a ram for them.
【在 v**e 的大作中提到】
: 毛鳖对土共的J20的看法
: ========>
: http://www.airfleet.ru/files/shaman/airfleet/Airfleet-2011-1%20
| w**h
发帖数: 1121 | 7 不排除这个可能。
但是现代战斗机一般会考虑多功能，可能歼20 为了这个目的，所以加大了武器舱。
missiles
【在 h*i 的大作中提到】
: 上面的转贴没贴文章最后的结论：J20是用来反舰的，是为美国海军定身制作的。
: ...the J-20 is a missile launching platform able to evade enemy
: interceptors by high cruise speed. The J-20 may prove a good interceptor, —
: very possibly. But its main task seems to be anti-shipping: firing missiles
: at enemy warships while denying their air defense cover.
: ....
: Since the memorable Battle of Hampton, the North Americans never
: lose at sea, and now their cheese boxes（泛指美军水面舰船，由Monitor号铁甲舰
: 来）sale when and where they want. China prepares a ram for them.
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