Take Off My Aviation Era

There is no other reason to say that the aerodynamic layout similar to the flying wing mode is the optimal solution. It is only because of the lift coefficient of this aerodynamic layout and the space utilization rate that is the most efficient among all startup layouts.

Let’s talk about the lift coefficient first. The flying-wing layout is a full-lift complex. The body and the wing are an integrated layout, which breaks the boundaries of the previous wing-body fusion and achieves a perfect unity. Because of this, the overall lift coefficient is extremely high. This ensures the basic maneuverability of the entire model.

Let’s talk about space utilization. The high space utilization of the flying-wing layout is recognized in the industry. This is from the B-2 stealth bomber with only half of the overall size of B-52, the range and ammunition carrying capacity reached B-52. It can be seen above the level of 70%.

If it is placed on other models, this kind of ultra-high space utilization is not a big deal. It can be placed on a vertical take-off and landing verification machine, but it is different, because in addition to the traditional high aero engine, the vertical take-off and landing verification machine is A lift fan is also installed at the rear of the cockpit.

No matter how you optimize and reduce weight, the huge space occupancy is equivalent to completely hollowing out the middle of the vertical take-off and landing verification aircraft. The straight drive shaft and the air ducts on both sides of the wings play a balancing role. The body is equivalent to the space occupied by these vertical take-off equipment more than 30%.

Combat aircraft moving toward these spaces will naturally have a corresponding reduction in fuel capacity and bomb capacity, and even compromise on flight performance, not only may the aircraft fail to fly into the sky.

At this time, China's aerodynamic layout similar to the flying wing model is highlighted by the high space utilization rate.

Even if a lift fan with a diameter of 1.8 meters is installed at the rear of the cockpit, and a drive shaft and air duct are arranged inside, the huge utilization space inside the flying wing layout can perfectly contain these devices while still having Objective fuel load and external weapon mounting capability.

It is necessary to know that the length of China Ascendas' vertical take-off and landing verification aircraft is 17.6 meters, the wingspan is 13.2 meters, and the wing area reaches 78.4 square meters. Such a huge wing area naturally becomes the best storage space for the built-in fuel tank, plus The sturdy middle fuselage guarantees the fuel capacity.

The huge wing area increases not only the internal space, but also the wing load that is essential for weapon loading. Due to the unique design of the flying wing layout, the bomb load is also guaranteed.

With sufficient fuel, excellent aerodynamic layout and sufficient ammunition, if there is no excellent aero engine to support it, all the previous efforts will have to be ruined.

As the so-called vigorous miracle, if you want to achieve empty weight, fuel load, bomb load 1:1:1, the performance of the engine must be strong, at least the thrust must be very large, otherwise it will not be able to support the entire aircraft. Basic performance.

In addition, the aero engine on the vertical take-off and landing verification aircraft must also have excellent fuel economy. Otherwise, if a fuel-eating tiger is like very water, let alone 6.2 tons of fuel, it will be doubled. The combat radius can't go up either.

Of course, the most critical thing is the limitation of the single-engine system. After all, vertical takeoff and landing combat aircraft only use a single-release bureau. If dual-engines are used, the complexity will soar at an exponential level, which is not cost-effective.

The problem is that if a single-engine engine is used, in addition to thrust and fuel economy, the most important thing is safety. This requires that the aero engine must be well-manufactured and stand the test.

Therefore, large thrust-to-weight ratio, excellent fuel economy and safety factor far exceeding that of ordinary aero engines have become the first choice for vertical take-off and landing combat aircraft.

And this is also the most maddening technical difficulty of this type of model.

Otherwise, all countries in the world know the benefits of vertical take-off and landing fighters, especially in Europe during the Cold War, facing the threat of Soviet artillery and missile washing. Combat aircraft may not have the opportunity to take off on the airport runway at all. At this time, they should not be picky about vertical take-off. The tactical advantages of the fighter jets are highlighted.

The problem is that after so many years, how come the United Kingdom, the Soviet Union, and the United States, which digs a wall from the United Kingdom, have the ability to develop and produce vertical take-off and landing fighters, but other countries have not even entered the market?

It is not how difficult the aerodynamic layout and technical design are, but the key is that the high-level aero engine keeps 99% of countries out of the threshold of this type of aircraft.

For example, France, as early as the late 1960s, was committed to developing vertical take-off and landing fighters. For this reason, it also specially modified several test and verification aircraft on the basis of Mirage III fighters. As a result, because the engines were not off, the conditions frequently appeared, and they were proud. The Gallic chicken was unwilling to subscribe for the "Sea Harrier" technology to John Bull, but was unable to face the consequences of the Soviet Union’s comprehensive firefighting. In the end, there was no way to simply create a short circuit that could be implemented on high-grade highways. Take off and land from the Mirage F-1 to make up the number.

Even the French with strong aviation skills are at a loss in this regard, let alone other countries.

It stands to reason that China's technology accumulation is not as good as that of its French counterparts. China's take-off also does not have the ability to impact such high-level aero-engines. It is not even clear how such engines are. At the end of the 1980s, the Tengfei Group revealed that it wanted to develop a vertical take-off and landing verification machine, but the industry was generally not optimistic about the root cause.

However, what good fortune is that the Soviet Union disintegrated in the early 1990s, and a large number of Soviet aviation production and development units that could not afford to eat were forced to market, and then the European and American aviation giants carried a sickle repeatedly and almost took the Russians back and forth. The roots of the leek are shaved.

At that time, the Ascendas Group made a timely move and wholly acquired the Yakovlev Design Bureau, which was on the verge of bankruptcy. Not only did it acquire the technology of the Yak-141 vertical take-off and landing fighter, it also added the supporting R-79-300 vector turbofan. Samples of the engine and part of the technology are available.

Originally, there was a certain accumulation of China's take-off in aviation engines. With these things, it was equivalent to having the key to turn on the special power of vertical take-off and landing fighters. So quickly embarked on imitation, and gave a very take-off code WD. —64ML turbofan engine.

The performance index is basically the same as that of the R-79-300 vector turbofan afterburner. The cruise thrust reaches 15.6 tons and the afterburner thrust is 19.7 tons.

However, in addition to the thrust data of the two eyes, other aspects of the WD-64ML turbofan engine have crotch. First, the bypass ratio is too large, reaching 0.81, which causes the engine diameter to be too large~www.readwn.com~Serious While squeezing the aircraft space, the thrust efficiency is not high.

The second is that the temperature in front of the turbine is too low, only 1620 Kelvin, which is 1346 degrees Celsius. This temperature is not to mention compared with advanced military engines in Europe and the United States. It is also compared with the 1600 degrees Celsius temperature in front of the turbine of China's Ascendas WD-60 series aero engine. A lot lower.

Affected by the low temperature in front of the turbine, the thrust-to-weight ratio of the WD-64ML turbofan engine has become very hip, only 5.46, which is on the same level as the "Speey" engine used on the FBC-1 fighter-bomber. .

In other words, in addition to thrust, the Russian R-79-300 has a huge gap with advanced engines in other aspects, and it is difficult to adapt to future combat needs.

It's a pity that the Russians don't seem to feel that their R-79-300 is pulling the hips. Instead, they heard that China Ascendas copied their R-79-300 engine and applied it like a dog skin plaster, requiring a patent fee for life and death.

I didn't think the R-79-300 was so good at first, and coupled with the tossing of the Russians without self-knowledge, China Soaring gave up imitation and directly started the road of self-upgrading.