Miloch
September 14th 20, 08:46 PM
https://www.foxnews.com/tech/the-chinese-j-31-5th-gen-stealth-fighter-may-be-a-total-f-35-rip-off
Chinese media reports have been referencing new photos of the emerging J-31
5th-Gen stealth fighter appearing on social media, ostensibly showing various
design improvements to the new radar-evading multi-role aircraft.
A May 5 report in the Global Times, an English-language Chinese newspaper, says
the new photos show an … “upgraded version with modifications made to its
aerodynamic design just like the prototype that made its maiden flight in 2016,
instead of the original version that made its public debut at Airshow China in
2014.”
Improvements or changes to the J-31 likely continue a longstanding pattern of
China’s apparent and somewhat visible effort to copy, steal or mirror designs
used for the U.S. F-35. Virtually all photos and renderings of the J-31, since
first unveiled, revealed a striking resemblance to the U.S. F-35. This does not
come to the surprise of many in the U.S., given China’s well-known and
documented cyberespionage efforts. A 2014 “U.S.-China Economic and Security
Review Commission” congressional report specifically cites a Defense Science
Board finding that Chinese cyberattacks resulted in the theft of significant
specs and technical details of a range of U.S. weapons systems — including the
F-35.
At the same time, a 2018 Pentagon news story about the Department of Defense’s
annual China report mentions that apparent similarities between the F-35 and
Chinese J-20 could very well be a result of espionage. A cursory look at the
J-20 does appear to show some resemblance to the F-35, particularly the blended
wing-body front end and internally built, conformal exhaust pipes. These
similarities do appear, despite the apparent differences, as the J-20 has a
wider and longer lower-body. However, available photos show an even larger
measure of similarity between the F-35 and Chinese J-31 multi-role fighter.
As recently as last year, another Global Times report said the J-31 showed
design improvements at the 2019 Paris Air Show. Photos from the story reveal
profound visual similarities between the F-35 and J-31. This is not without
precedent, as the Chinese media itself has noted similarities between the two
aircraft. Portions of a story from the Chinese government’s “People’s Daily
Online” as far back as 2013 specifically cites design similarity between the
emerging Chinese J-31 and the F-35, writing that the “J-31 and F-35 use the same
DSI inlet (non-boundary layer-separated lane supersonic inlet).” The only major
difference, the paper notes, is that the U.S. has an F-35B Short Take Off and
Landing variant and that the J-31 uses two engines compared to the F-35’s single
engine propulsion configuration.
The People’s Daily Online article’s reference to a “non-boundary layer separated
lane supersonic inlet” appears both interesting and significant, as it pertains
to designs engineered to manage heat and air movement signatures demonstrated by
the aerodynamic phenomenon of air flow surrounding supersonic flight. “Boundary
layer” aerodynamics, referring to the air flow surrounding a weapon or platform
as it transits, can greatly impact the flight stability and stealth
characteristics of an aircraft.
A pertinent comparison can be found in the Air Force Research Laboratories’
current work on “boundary layer phenomenology” related to next-generation
hypersonic weapons. Senior Air Force science and technology leaders and weapons
developers told me at the Air Force Association symposium in 2019 that “boundary
layer phenomenology” was figuring prominently in ongoing research and
development regarding future weapons and platforms. Managing heat flow and
temperature is, of course, vital to maintaining flight stability for hypersonic
weapons traveling at speeds up to five-times the speed of sound. Developers seek
to engineer configurations that will generate a “laminar” or smooth airflow as
opposed to “turbulent” boundary layer to enable a weapon to sustain an accurate
trajectory and manage excessive heat.
Therefore, by extension, it seems apparent the same aerodynamic principles apply
to stealth aircraft configurations that seek to manage the heat signatures and
turbulence potentially generated in the air flow boundary layers of stealth jets
flying at supersonic speeds. Accordingly, a “non-boundary layer separated lane”
for airflow, (as cited by the People’s Daily Online article) that does not break
up or radically change airflow trajectory, could not only ensure smoother flight
at high speeds but also help manage temperature. Of course, there would be
significant differences between the thermal management technical engineering
needed for hypersonics and stealth aircraft, yet smoother wing-body melded
external designs, absent hard or protruding edges, clearly bring the added
advantage of a smoother and cooler air flow boundary layer. Along these lines,
the 2019 Global Times report details a few design changes to the 2019 J-31
which, according to the photographs, show a smoother, less-jagged exterior
behind the cockpit as opposed to earlier models.
The Chinese newspaper stops short of exploring a fully-detailed discussion of
aerodynamic designs related to the aircraft, but does cite a Chinese Air Force
test pilot expert as saying “the J-31’s stealth aerodynamic design, stealth
engine design and stealth coating design have all reached internationally
advanced standards in stealth technology.” (China’s Air Force test pilot expert
Xu Yongling.)
However, external configuration and some elements of visible heat-signature
management represent merely a few of many characteristics when it comes to
stealth technology; stealth designs also often incorporate internally-built
engines, radar absorbent coating materials and internal weapons bays, among
other things. Along these lines, the People’s Daily Online report makes the
claim that the J-31 has a superior weapons payload capability compared with the
F-35. However, available specs report that the J-31 travels with six external
weapons hardpoints… the same number as the F-35.
As for how the J-31 may be employed, Chinese and U.S. newspapers are filled with
speculation; some reports say the fighter is intended for export as a way to
counter the reach and scope of the F-35, however other reports cite Chinese
officials saying the J-31 is intended for domestic use and possibly could even
fly off of Chinese aircraft carriers.
Chinese progress with the J-31 calls to mind several timely strategic
calculations. A more recent Congressional report, the 2018 U.S. China Economic
and Security Review Commission, makes specific reference to concern regarding
China’s expansionist aims when it comes to projecting air, land and sea power.
The text of the review points to dramatic upticks in “long-distance over-water
training” exercises over new areas in recent years which, the study goes on to
suggest, improves the PLA Air Force’s capability to gather intelligence and
“execute maritime missions against the U.S.”
“In November and December 2017, China’s People’s Liberation Army (PLA) Air Force
conducted at least nine long-distance training flights over maritime areas along
China’s periphery, continuing a trend that began in 2015,” stated the 2018 U.S.
China Economic and Security Review Commission.
All of this pertains to the often and widely discussed recognition that China
has long-since passed its ambitions to operate as a dominant regional power and
migrated aggressively toward positioning itself as a massive, leading global
power.
*
Chinese media reports have been referencing new photos of the emerging J-31
5th-Gen stealth fighter appearing on social media, ostensibly showing various
design improvements to the new radar-evading multi-role aircraft.
A May 5 report in the Global Times, an English-language Chinese newspaper, says
the new photos show an … “upgraded version with modifications made to its
aerodynamic design just like the prototype that made its maiden flight in 2016,
instead of the original version that made its public debut at Airshow China in
2014.”
Improvements or changes to the J-31 likely continue a longstanding pattern of
China’s apparent and somewhat visible effort to copy, steal or mirror designs
used for the U.S. F-35. Virtually all photos and renderings of the J-31, since
first unveiled, revealed a striking resemblance to the U.S. F-35. This does not
come to the surprise of many in the U.S., given China’s well-known and
documented cyberespionage efforts. A 2014 “U.S.-China Economic and Security
Review Commission” congressional report specifically cites a Defense Science
Board finding that Chinese cyberattacks resulted in the theft of significant
specs and technical details of a range of U.S. weapons systems — including the
F-35.
At the same time, a 2018 Pentagon news story about the Department of Defense’s
annual China report mentions that apparent similarities between the F-35 and
Chinese J-20 could very well be a result of espionage. A cursory look at the
J-20 does appear to show some resemblance to the F-35, particularly the blended
wing-body front end and internally built, conformal exhaust pipes. These
similarities do appear, despite the apparent differences, as the J-20 has a
wider and longer lower-body. However, available photos show an even larger
measure of similarity between the F-35 and Chinese J-31 multi-role fighter.
As recently as last year, another Global Times report said the J-31 showed
design improvements at the 2019 Paris Air Show. Photos from the story reveal
profound visual similarities between the F-35 and J-31. This is not without
precedent, as the Chinese media itself has noted similarities between the two
aircraft. Portions of a story from the Chinese government’s “People’s Daily
Online” as far back as 2013 specifically cites design similarity between the
emerging Chinese J-31 and the F-35, writing that the “J-31 and F-35 use the same
DSI inlet (non-boundary layer-separated lane supersonic inlet).” The only major
difference, the paper notes, is that the U.S. has an F-35B Short Take Off and
Landing variant and that the J-31 uses two engines compared to the F-35’s single
engine propulsion configuration.
The People’s Daily Online article’s reference to a “non-boundary layer separated
lane supersonic inlet” appears both interesting and significant, as it pertains
to designs engineered to manage heat and air movement signatures demonstrated by
the aerodynamic phenomenon of air flow surrounding supersonic flight. “Boundary
layer” aerodynamics, referring to the air flow surrounding a weapon or platform
as it transits, can greatly impact the flight stability and stealth
characteristics of an aircraft.
A pertinent comparison can be found in the Air Force Research Laboratories’
current work on “boundary layer phenomenology” related to next-generation
hypersonic weapons. Senior Air Force science and technology leaders and weapons
developers told me at the Air Force Association symposium in 2019 that “boundary
layer phenomenology” was figuring prominently in ongoing research and
development regarding future weapons and platforms. Managing heat flow and
temperature is, of course, vital to maintaining flight stability for hypersonic
weapons traveling at speeds up to five-times the speed of sound. Developers seek
to engineer configurations that will generate a “laminar” or smooth airflow as
opposed to “turbulent” boundary layer to enable a weapon to sustain an accurate
trajectory and manage excessive heat.
Therefore, by extension, it seems apparent the same aerodynamic principles apply
to stealth aircraft configurations that seek to manage the heat signatures and
turbulence potentially generated in the air flow boundary layers of stealth jets
flying at supersonic speeds. Accordingly, a “non-boundary layer separated lane”
for airflow, (as cited by the People’s Daily Online article) that does not break
up or radically change airflow trajectory, could not only ensure smoother flight
at high speeds but also help manage temperature. Of course, there would be
significant differences between the thermal management technical engineering
needed for hypersonics and stealth aircraft, yet smoother wing-body melded
external designs, absent hard or protruding edges, clearly bring the added
advantage of a smoother and cooler air flow boundary layer. Along these lines,
the 2019 Global Times report details a few design changes to the 2019 J-31
which, according to the photographs, show a smoother, less-jagged exterior
behind the cockpit as opposed to earlier models.
The Chinese newspaper stops short of exploring a fully-detailed discussion of
aerodynamic designs related to the aircraft, but does cite a Chinese Air Force
test pilot expert as saying “the J-31’s stealth aerodynamic design, stealth
engine design and stealth coating design have all reached internationally
advanced standards in stealth technology.” (China’s Air Force test pilot expert
Xu Yongling.)
However, external configuration and some elements of visible heat-signature
management represent merely a few of many characteristics when it comes to
stealth technology; stealth designs also often incorporate internally-built
engines, radar absorbent coating materials and internal weapons bays, among
other things. Along these lines, the People’s Daily Online report makes the
claim that the J-31 has a superior weapons payload capability compared with the
F-35. However, available specs report that the J-31 travels with six external
weapons hardpoints… the same number as the F-35.
As for how the J-31 may be employed, Chinese and U.S. newspapers are filled with
speculation; some reports say the fighter is intended for export as a way to
counter the reach and scope of the F-35, however other reports cite Chinese
officials saying the J-31 is intended for domestic use and possibly could even
fly off of Chinese aircraft carriers.
Chinese progress with the J-31 calls to mind several timely strategic
calculations. A more recent Congressional report, the 2018 U.S. China Economic
and Security Review Commission, makes specific reference to concern regarding
China’s expansionist aims when it comes to projecting air, land and sea power.
The text of the review points to dramatic upticks in “long-distance over-water
training” exercises over new areas in recent years which, the study goes on to
suggest, improves the PLA Air Force’s capability to gather intelligence and
“execute maritime missions against the U.S.”
“In November and December 2017, China’s People’s Liberation Army (PLA) Air Force
conducted at least nine long-distance training flights over maritime areas along
China’s periphery, continuing a trend that began in 2015,” stated the 2018 U.S.
China Economic and Security Review Commission.
All of this pertains to the often and widely discussed recognition that China
has long-since passed its ambitions to operate as a dominant regional power and
migrated aggressively toward positioning itself as a massive, leading global
power.
*