Take Off My Aviation Era

Of course, it is still far away to talk about c-17 at the moment when it has just entered the 90s. In addition, McDonnell Douglas was dismantled as early as the early 1980s. Therefore, in today's world, Yun-15plus has become the only amount already available. It is a light tactical transport aircraft using external blown flap technology.

Its biggest feature is that the blowing wing **** account for 75% of the trailing edge of the entire wing. In other words, except for a small area of ​​the wing tip, most of the trailing edges of the wing can be deployed downwards until Cover the engine tail nozzle completely.

So that when people look forward from the tail of the aircraft, they will only see the **** that are like large birds converging their wings and protecting the cubs, protecting the front engine's large-angle deflection and drooping flaps.

In this way, the airflow generated by the engine's tail nozzle will deflect the airflow down like a deflector under the action of the drooping wing. As for analyzing the scattered airflow between the two flaps, there is no waste, because the arc is drooping. The **** just produce the "Conda effect" on the escaping airflow to guide the airflow to deflect downward again and continue to generate upward lift.

Coupled with the supercritical airfoil that Ascendas Group has been studying for many years, the powerful airflow emitted by the Yun-15plus engine can be converted into full lift when the engine starts, thereby shortening the take-off distance and accomplishing the purpose of short take-off.

When landing, the blown wing **** that are put down can become a great drag reduction mechanism, which cooperates with the drag reduction plate above the wing, the engine's reverser and the landing gear brake system to complete the short distance of 15plus. landing.

All in all, a set of blowing wing flap technology gives Yun-15plus unparalleled short takeoff and landing capabilities.

But with such a good technology, why didn't the Soviet Union's Antonov and the United States' Boeing use it, but instead created a rather different kind of security?

It's not that I don't want to use it, but that this technology seems simple and the principle is not difficult, but it is not easy to create it.

First of all, the idea of ​​using the wake of a jet engine as the lift for the take-off of an airplane is really good, but it is important to know that the temperature of the wake of the jet engine is not low, and ordinary aluminum alloy materials simply cannot withstand such high temperature burning. After two blows, it will be scrapped by the engine.

Only high-temperature resistant titanium alloys can do the job, but the problem is that the flap area, which occupies more than half of the trailing edge of the wing, is so large and there are so many small connecting rods and other precision parts. If all titanium alloys are used, the cost will definitely be Biao up.

In contrast, the shoulder-mounted engine layout is adopted, and only a small part of the titanium alloy skin is used to wrap the part burned by the wing near the engine tail nozzle. The cost is compared with the air blower. The aircraft of the same type is lower by more than one grade.

Secondly, in terms of control, the blowing flap is generally divided into two layers, and each layer is a movable part. This brings about a problem, that is, how to integrate such an important and complicated wing movable part. Into the operating system of the entire aircraft.

Whether it is mechanical hydraulics or fly-by-wire control, it is not a job that can drive aeronautical engineers crazy. After all, the influence of moving parts of the wings on the control of the aircraft is not generally large, and a failure may be fatal.

In contrast, the shoulder-mounted layout has no concerns in this regard. Apart from the weird shape and the influence of air resistance, the wing is not very complicated, and it can be constructed according to a mature aircraft operating system. , At least slightly adjusted according to aerodynamic factors.

The last and most critical thing is that it is manufactured. An-this kind of aircraft looks weird, but in fact, the manufacturing process is not more complicated than traditional transport aircraft, but the location of the engine is different.

Airplanes with blown wing **** are different. It is the same when looking at the wings during static display. The two wings are pressed on the fuselage, but in fact they contain extremely cutting-edge aerodynamics.

To achieve these technologies and meet the design requirements, the requirements for processing and production are almost abnormally high. Not to mention the processing of other supercritical airfoils, few countries in the world can do it, because That kind of radian and curvature, and the final shape can't be described in words.

If all these are listed, the pragmatic Soviet Union will naturally not be so complicated. The nature of the bear is simple and direct, so there is An-72.

The Boeing of the United States has technology, but the capitalists pay attention to cost-saving, blowing the flap is too expensive, even if it is so expensive, no one buys it, so it has.

McDonnell Douglas is hard to resist, and the result is that the cost remains high. When bidding for the successor model of the c-130, the unit price made the wealthy U.S. Air Force burst into tears. In the end, forget it, c-130 is pretty good. , The change could take another 30 to 40 years, so McDonnell’s was cut.

Although McDonnell Douglas proved with the later c-17 that blowing wing **** were the mainstream and the kingly way, at that time McDonnell Douglas had already been swallowed by Boeing, and c-17 also became Boeing's top card from the oiran of McDonnell Douglas.

Can the small Ascendas Group be able to afford technologies that even aviation giants like the Soviet Union and the United States cannot afford?

The answer is naturally yes, otherwise Zhuang Jianye's head was drawn to make such a money-burning thing.

As for why, it’s very simple. The US and Soviet aviation giants engaged in short take-off and landing transport aircraft in the 1960s and 1970s. At that time, the composite materials had not been out of the laboratory. The cost of smelting titanium alloys was scary, even the drawings They had to be drawn manually one stroke at a time, and the popularity of high-precision CNC machine tools was not high, which led to the fact that the cost of using blown **** at that time was really not too high.

The Ke Tengfei Group was determined to do transportation—15plus was in the late 1980s. At this time, aviation technology, especially aviation material technology, had made a qualitative leap, and aviation processing technology had also made rapid progress.

Not only can the production of blown **** be realized, but the cost is greatly reduced.

Of course ~www.readwn.com~ this is not important. The most important thing is that Ascendas Group has accumulated a certain degree in materials, aviation design, aerodynamic layout, production and processing for so many years, and it can completely control this kind of blowing. Design, processing and manufacturing of complex airfoils of flaps.

Not to mention anything else, let’s take the supercritical wing as an example. As early as the mid-1980s, Teng Airfield had cooperated with the military to develop a supercritical wing non-detection—8plus high-altitude observation drone. .

After that, a lot of experiments and research were done in this area. By the time of the development and production of Yun-15plus, Ascendas Group already had rich experience in this area, and it was not a problem at all.

As for high-temperature-resistant lightweight materials, Ascendas Group has more choices, such as aramid fiber honeycomb structure combined with titanium alloy; carbon fiber reinforced titanium-based composite material; type carbon fiber composite material; even there are still under development, The m-series carbon fiber material that can withstand higher temperatures and offset greater tension and is higher than the t-series index.

With modern processing equipment such as CNC shot blasting machine, CNC high-pressure water cutting machine, CNC laser welding equipment, laser additive, flexible fixture, automatic riveting, etc., as well as the cost advantage of Ascendas Group itself, it produces a cost-effective short distance starting Is it difficult to lower a tactical transport aircraft?