Chinese giant wind tunnel and J20

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Reprint:

J20aircraft aerodynamic layout, don't blow a thousands of tens of thousands of times, how can God?

Visit a mountain tunnel, this is a wind tunnel, called the high-temperature electric arc wind tunnel, is used to simulate the rocket flight or hypersonic flight. Wind tunnel itself is not large, the simulation extreme conditions ( wind tunnel are not big wind tunnel is a low speed wind tunnel ), but it is strange that the laboratory wall structure steel is very strange, very thick, so a storey house, there seems to be. The results presented, it is the transmission of " line"! High temperature arc wind tunnel to use electric power to produce electric arc, these wires to transmit thousands and even tens of thousands of amperes, attention is not in tens of thousands of volts, but ampere! To know that under normal circumstances, the amp is not current, so that thousands of thousands of amperes, normally on the meaning of" wire" simply cannot withstand, so use these very thick steel for transmission line"".

The high-temperature electric arc wind tunnel is a very wonderful thing in the world, not a few. Introduction of high technology, Europe was a make aliyah Na rocket research delegation to communicate, heard that the eastern China, not to see, because they do not believe that China can make that. The results showed them, like an instantaneous power Liubaiqian tile, they ( the European delegation ) extreme shock, because not only do we have, and the power is higher than they are! Before the Europeans say they say high and the wind tunnel instantaneous power is Sibaiqian tile, seem to be very proud.

Engineering by another laboratory wind tunnel, then put the wind tunnel to cover, not to see them, if they ask. Do you know the wind tunnel instantaneous power is how much? Fifty thousand watts! Than Europeans know for high by two orders of magnitude! Europe is a communications satellite what, China must do can be recycled to the satellite, and reentry after hitting the ground intercontinental ballistic missiles, which are very high speed flight, without the wind, do not become

 

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March 5, 2010 article: China 's new five generation machine - 20 F, is a screening test flying in wind tunnel

This article from the 西陆网首页-中国第一军事门户网站 text link: http: / / junshi.xilu.com / 2010 /0305 / news_44_69690_2.html

 

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CCTV < < military reports > > assembly to a base in the low speed wind tunnel three mysterious aircraft model, analysis of single ARJ21, localization of IL - 76in6 engine, wherein large Avion, suspected domestic version225

 

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J20 using a canard configuration, a more excellent vortex lift movable strake and differential and double vertical tails. This layout and the type three conventional layout of the four generation machine are very different. And two large pelvic fins and four believe it is a great action barrel, show and his country four generation machine for concise appearance is quite different. But why are these things?

J20, wing based on visual, can be classified as the alienation of the delta wing. But while on the wing, which facilitates off up and pitch control, differential left wing, can be thought of not simply for vortex lift design. J20 also uses a large movable strake, this can make J20in total lift has relatively good performance. While the fuselage lifting action, not clear. The pelvic fins are a mystery. Because other countries three four generation machine do not use the pelvic fins, while J20pelvic function problem. It is now generally accepted as the front wing and the edge of the generated vortex affect the vertical tail efficiency at high angles of attack, and when the fin efficiency, so it is necessary to supplement the operating efficiency of the longitudinal fins. That could explain the pelvic fins of application

The tail is also a differential. Basically you can think the whole tail can be reached to ninety degree rotation. Can form a pneumatic brake and the role of fighter plane of certain actions required. While the vertical longitudinal control purposes, can believe that the use of pelvic fins to supplement the efficiency. But the motor performance, because emphasize than T50 and F22more complex movements.

Su 27Cobra maneuver, was all pilots dream. While the United States F22needle type motor more other all pilots used. While the large attack angle, post-stall maneuvering, the moment is the four generation machine special technical characteristics. While J20uses differential front wing and differential vertical coordination, can be considered in the complex angle when another pneumatic control mode, will be the pursuit of extreme maneuverability. Therefore, there is reason to believe that, at least in J20fly all I want to do more than Russia further.

Three generation machine, digital flight control effect, the flight attitude control in the envelope, as a pilot in the envelope of free flight, can be said to be in the envelope flight safety, and J20 may in the fly all I want make a bigger step.

While the aircraft is the soul of avionics. Exactly how J20avionics after all how? We can see from the attempts to explore. As we all know, China 's first integrated avionics project started1979, but because of China's electronics industry base difference until the late ninety's to the Western equivalent of seventy time integrated avionics. But there are a large number of the original device also imported. While the eight six three scientific planning, based on information technology, electronic technology research after the start, integrated circuit technology, IT technology to carry out the corresponding. And the ninety time in the development of the aircraft when Western technology system. To this service, generally fly fire cross-linking as a representative of the international Three Generation Avionics technology based on mature.

The four generation avionics, except fire fly pusher and a cross-linking, also the network data transmission system. China in this respect, from the beginning of eight six three, has been tracking research, now, new domestic aircraft central computer and the backplane bus already in a flying school L-15 one machine test for a long time. Basically you can think mature.

While China is put forward in ninety time with optical fibre instead of cable, who believe in China in the algorithm, hardware has great progress under the premise of realizing the. And now the West and Russia still use cable wiring, but now more and more responsible for the electromagnetic environment, the weight of the cable, vulnerable to interference and attenuation and aberration contrast light soldering no advantage, and light soldering can make use of fighter aircraft to reduce some weight. China in this field has been very long time research and development, believe the J20 will use these technologies. While the computer aspect, China is fully aware of the risk of foreign products, so in the early ninety 's began to invest no commercial prospects of domestic CPU! Godson. It is dragon core, to make Chinese independent fighter computer become possible. Dragon core frequency, reached a few years ago western technology level, it can be assumed that the J20's central computer than F22ten years ago the computer better. And flight control, due to the complexity of the aerodynamic surface, so there must be a high reliable control system.

And we can see the wing has four cylinder, although T50 has a cylinder. But we didn't see J20nose portion having photoelectric radar, while in stealth times today invisible to radar, optical detection of compensation is a choice. While the J20seat window in front before place, it is possible for pilots to have better vision and design. But the problem is that the traditional radar, occupy first part of large space, the J20why small airplane electronic warehouse?

I think, this and Chinese new generation radar, the conventional mechanical scanning antenna, a part of machinery occupies a part of space, so before the airplane hand to a window has a great distance. Using array antenna duty reduced the mechanical parts, while the processing computer can rely on to other place. Su27 and15B photoelectric radar is a remarkable characteristic, but J20not found. This is most likely in a new generation of computer and a bus, while Russia photovoltaic radar as a systematic approach, and the light detecting device and the central computer coach, thus saving space and energy. Can turn a light sensing transfer to other places, can also be used to form the advantage of multi point detection. It is estimated that the Chinese people a new choice.

Radar, radar ranging from China to Doppler radar, has gone through forty years of hard development. While the eight six three project began, a can be compatible with a variety of modes of the antenna system began to study, and in early twenty-first Century in the Navy with the more powerful than conventional mechanical scanning radar antenna. By 2007, China Academy of lightning a multi mode, multi band phased array radar installed in the112factory began to experiment on a plane. And up to now has basically been successful.

The above problems, China 's airborne radar, reach F22beginning level is not a problem. And Russia, was on an integrated circuit has not made any achievements, plus twenty years for economic reasons, leading to cooperate with India T50 to the central computer research to India. From the things that show Russia in the conditions of modern electronic industry.

 

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China 's engine research, has not been correct leadership and understanding. In fact, Chinese engine independent research, is a relatively early, as early as1958wiped out to teach a research, but due to various reasons, to the early eighty's, China is the only Soviet aid engine imitations in the application, although independent research and never part. While the engine industry needs based, China has relatively weak impression..

Recently, the United States think tank" insight into Chinese" column was the latest information: China in jet engine technology made a major breakthrough, annihilates -20 is equipped with two sets of 18 tons thrust WS-15" Taihang" engine has become a reality, the basic performance caught the Russian and American and European similar engine, become the world aviation records a prospect has clear.

The West has been that China from Russia or Ukraine to introduce the relevant technology, makes WS-15" Taihang" engine to complete the great leap forward of the breakthrough, this speculation is too narrow. In fact, Chinese aircraft manufacturing industry the biggest problem is the engine thrust-weight ratio does not go on, mainly for the two problems, one is the materials, two is the design and processing.

However, nothing is impossible to a willing heart, with Chinese stand on one's own intellectual property rights of a new generation of aerospace engine materials finally the successful development of high performance, high temperature alloy materials of high niobium-titanium-aluminum enters industrialization phase. New alloy can improve the turbofan blade is high temperature resistant ability, allows to increase the engine air inlet temperature, increase the engine thrust. In Europe and the United States and Japan and other countries with nickel base high temperature alloy, the development of China high Niobium-Titanium Alloy High Temperature density more than half, more to the point, because of the high density low half of Niobium-Titanium Alloy, which can greatly reduce the weight of the engine, thereby greatly improving engine thrust-weight ratio

Metal science and materials scientist Shi Changxu in January 14, 2011for his outstanding contribution to the development of high performance fighter, was the state supreme science and technology award.

According to the Chinese mainland research aircraft engine scientists, once served as the Chinese Academy of Sciences Metal Research Institute Division professor has developed several series of a heat resistant alloy.

These alloys in the early decades ago would have been developed, but because the aircraft engine used by the metal material takes a long time to test, so the teacher until recently, developed by Professor alloy materials for China began manufacturing aircraft engines.

In 1955, Shi Changxu bids farewell to his teaching post at the Massachusetts Institute of Technology set foot on return journey. He is the United States government banned returned to their socialist motherland more than 30Chinese American scientists. He and Tsien Hsueshen almost the same time leaving the United States, Tsien Hsueshen is the California Institute of Technology rocket expert, which later became the founder of China aerospace.

Shi Changxu arrived in Shanghai, was immediately assigned to Shenyang in Northeast China's Liaoning Province, where there is a heavy industry base, the purpose is to improve the production of steel. Later, relations between Beijing and Moscow rapidly deteriorated, the Russians no longer help their old allies developed fighter. Chinese military turned to Shi Changxu and other scientists.

By virtue of hard work, talent and luck, Shi Changxu not only using him in western countries learn traditional methods need to create alloy, but also create some new alloy series.

The research and development of new alloy in laboratory test performance is quite good, that no one dared to use them. For safety reasons, aircraft designers followed the traditional alloy manufacturing Chinese mass production of aircraft engine, its performance is seriously lagging behind the foreign similar products.

Thereafter, Shi Changxu developed the alloy series began in the industrial field acceptance of long journey. Until recently, due to their application in F - 20as the most advanced fighter aircraft, to acquire the design fully recognized.

School of materials science and engineering, Shanghai Jiao Tong University professor Zhang Lanting says, this is Chinese aviation material science the long-awaited highest honor. Professor Zhang pointed out, some people think, China does not have the manufacturing of high performance aircraft engine materials, but they are wrong. Professor Zhang said, in fact, many of our most superior quality materials, but in order to make aircraft designers convincingly using these materials, we must carry out decades of trials -- is usually 30 years -- to ensure absolute safety. In the next 10 years, China produced the engine will start in civilian areas, to replace imported engine. In the military field, domestic replace imported engine work has begun.

 

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Mianyang Tunnel Group - Asia's largest air wind tunnel test center

The total investment of the project: -

Project deadline:1976-- so far

2.4meter transonic wind tunnel large circular guide hole, the height of more than two floor

NF-3machine in low speed wind tunnel to "win - 8" model aircraft were blowing test

 

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