J-10 - Lavi with Chinese Characteristics?
Even though Israel stopped its military exports to the PRC, it remained the second most important source of advanced military technology to the PRC [after the Soviet Union] due to its cumulative effect. Israel’s principle motivation for its arms relationship with the PRC was to support its domestic arms industries, whose competitiveness required exports for support. However, some Israeli officials claimed that one benefit of its sale of LAVI fighter technology to China was been to prevent sales of surface-to-surface missiles to Syria.
The Lavi fighter (roughly comparable to the U.S. F-16) was developed in Israel during the 1980s with approximately $1.5 billion in U.S. assistance, but did not get past the prototype stage. The 1997 edition of ONI's "Worldwide Challenges to Naval Strike Warfare" said that the design for China’s J-10 fighter (also known as the F-10 — the designation used in the report) “had been undertaken with substantial direct assistance, primarily from Israel and Russia, and with indirect assistance through access to U.S. technologies.”
Richard D. Fisher stated in 2004 that "The most famous PRC-Israel project has been the co-development of the Chengdu Jian-10 (J–10) 4th generation multi-role fighter. This project drew heavily on Israel’s Israeli Aircraft Industries LAVI advanced fighter, which was terminated after the U.S. withdrew its financial and political support. In 2003, a Russian source who visited Chengdu in the early 1990s remarked that it was possible to view Hebrew language placards on the walls where work was being done on the J–10. But the LAVI, in turn, drew heavily from U.S. technology, including some associated with the Lockheed-Martin F–16 fighter. U.S.-origin technology in the J–10 may include avionics, advanced composite materials and flight control specification. As more details about the J–10 have surfaced, it is increasingly apparent that Chengdu pooled technology influences from Israel and Russia to make this new fighter."
In January 2007 China said that the J-10 fighter was put into service with the PLA Air Force and that the J-10 was the first advanced fourth-generation fighter that China developed on its own. By 2010, the PLA Air Force was believed to have about 100 J-10 fighters. According ot a 2011 Congressional Research Service Report, "the J-10 was based on the U.S.-Israeli Lavi project of the 1980s." CRS stated that in 1991 China reportedly started cooperation with Israel in the development of the J-10 fighter, based on the Lavi fighter project (with U.S. technology) that was canceled in 1987 and was comparable to the F-16 fighter.
Some Chinese sources give a rather different view, noting that the J-10 plan was put forward earlier than LAVI. The J-10 plan was finalized in April 1982, while LAVI was in October of the same year. But one Chinese source reports "After Israel transferred the forced-terminated "Lavi" fighter plan to China in 1987, China officially started the research and development of the J-10 fighter code-named "Project Ten" in 1988." Chinese analysts note there is a huge difference in aerodynamic shape between the Israeli Lavi fighter and the domestic J-10 fighter. The distance between the J-10 canard and the wing is much greater than that of the LAVI. This is the key, and this is the essential difference. The J-10 was originally designed as a homeland air defense fighter with interception requirements.
The difference between J-10 and LAVI like a horse and a camel. A very important point in the aerodynamic design of a high lift-to-drag ratio is aerodynamic trim. The negative trim of the conventional layout will also bring unfavorable resistance to the overall lift-to-drag ratio, and the cost of the lifted layout is much smaller. The J-10's trim arm is much longer than LAVI, and its relaxed static stability is much wider than LAVI. The LAVI canard is basically a vortex generator. In addition, the distance between the LAVI wing and the canard is too close, so that the drag generated by the eddy current and the basic trimming ability make the high-speed performance. The distance between the J-10 canard and the wing is much greater than that of the LAVI. This is the key, and this is the essential difference.
Lavi uses a super close-coupled canard + swept wing design, which is a marvel in the history of aircraft design. Affected by the downwash of the canard, the effective angle of attack of the inner section of the main wing has been significantly reduced, but no forward cutting angle or large upward twisting measures have been taken to compensate. The inner main wing that provides most of the lift will appear when flying at high angles of attack. The section had not stalled, but the outer wing section, which was equipped with ailerons and was responsible for the roll, stalled first. In addition, the longitudinal control moments of the trailing edge flaps and canards are too short, and it is difficult to produce enough bowing moment when flying with high lift coefficient and high angle of attack. Once stalled, there is no way to recover. This is that Lavi's available angle of attack is severely restricted.
On the other hand, the J-10 adopts a unique mid-range coupled canard layout, which takes into account both pitch control and vortex generation. Although the torque is shorter than that of a typhoon, it has a larger wing area, variable camber in the span, and a higher lift coefficient. In the upper wash flow field of the main wing, the canard with better lift efficiency has obtained excellent supersonic pitch control authority. In addition, the supersonic shock lift of the intake swash plate (type A) or bulge (type B and C) is used to unload the canard, and the high-speed flight performance is no less than that of the canard.
In addition, the larger canard also ensures strong enough vortex generation and control capabilities in the coupled state. The adverse effect of the canard downwash on the main wing is solved by greatly twisting the main wing spanwise and increasing the angle of attack of the inner wing section. The large canard can also realize the yaw control by actively controlling the vortex field. The supersonic lift-to-drag ratio of the J-10 and Typhoon when mounted in a typical air combat is not less than 4.0, and the high-speed flight performance is significantly better than the typical third-generation aircraft. They are classic products of the "pointing maneuvering" design concept.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
