Fortunately, she now has the absolute spatial deduction assistance of the Enlightenment Stele, which is clearer and more intuitive than just trying to build a model in her mind before. She can physically perceive the advantages and disadvantages of the optimization direction and speed up the optimization process.
Within the limited time, we should compress the time as much as possible and not be the one who lags behind.
STOVL fighter jets are actually the inevitable direction for the sustainable development of future aviation technology.
Most flying microbes in nature actually take off and land vertically, or in short descents. From flies, mosquitoes, and insects to most birds, microbes have never been seen flying on Earth.
In order to facilitate take-off and landing, a road runway was specially built, but it was actually a technical flaw and a second-rate option.
Most large birds can use river gliding to aid flight.
But in real life, since the large-scale active service, the world immediately realized that it had taken up too much load in the sudden battle on the ground and the comprehensive ups and downs at sea.
A good resource can be used to polish a jade. Wu Tong pondered over it, and the confidential information she had read before flashed through her mind. From the perspective of equipment history, the propulsion system of the STOVL fighter has three engine models.
That is, the Harrier "Pegasus engine" from Britain, the R-79+RD-41 engine of the Yak-141 of the big brother next door, and the F135 engine of the United States.
These three engine models also correspond to three different technical solutions.
The Pegasus engine has a thrust reversing scheme of rotating exhaust nozzles. When the aircraft takes off and lands vertically, the nozzles eject air downwards.
The most significant feature of this engine is its "lift-thrust integration," meaning that a single engine provides both cruise thrust and vertical lift. It boasts a simple, compact structure, low deadweight propulsion system, excellent short-range takeoff and landing performance, and even vertical takeoff capability.
However, the disadvantages are also obvious. Since the rear nozzle ejects hot gas, it causes a serious problem of exhaust re-inhalation. Because the hovering altitude is low during vertical take-off and landing, the oxygen-poor high-temperature jet bounces off the ground and is easily inhaled by the engine again, reducing engine efficiency and even causing surge.
Vertical takeoffs are very fuel-intensive. It is said that a Harrier uses up between one-third and one-quarter of its internal fuel in one vertical takeoff, leaving it with a combat radius of only about 100 kilometers.
In addition, the Pegasus engine has a large cross-section, which leads to large supersonic drag, so the Harrier has always been a subsonic fighter; in addition, the control system is very complex due to the adjustable nozzle area and afterburner, which is also a technical problem.
At present, this technology has lost its practical significance and can only serve as a reference in the history of engines.
The R-79+RD-41 engine of the Yak-141 was developed ten years later than the Pegasus, but correspondingly, it went a step further than the Pegasus engine.
The Yak-141's defining feature is its "separated lift and thrust" design. The cruise and lift engines each perform their respective functions, ensuring the efficiency and effectiveness of the cruise engine. This made the Yak the world's first supersonic STOVL fighter. During flight tests, the Yak-141 even reached a maximum level flight speed of Mach 1.4-1.7.
However, drawbacks are unavoidable. The high-temperature airflow from the cruise and lift engines is particularly prominent. When the aircraft is hovering, the high-temperature airflow is ejected from the engine nozzle and diffuses outward after reaching the ground.
The low-pressure area formed below the fuselage, creating a suckdown effect that would "suck" the aircraft firmly. This is why the Yak-36 crashed on its first test flight and failed to take off. Later, due to the disintegration of the neighboring big brother and a series of major national changes, the optimization of the Yak-141 could not continue, and unfortunately it was undone.
Finally, there is the F135 engine used by the F-35.
It is developed based on the F119 and adopts the F119's core engine components: high-pressure compressor, combustion chamber and high-pressure turbine. The fan, low-pressure compressor and low-pressure turbine are redesigned from the F135 engine.
The model used for the short vertical takeoff F-35B is F135-PW-600, referred to as F135 engine.
There is a rumor in the circle that during the selection of F-35B vertical launch propulsion technology, part of the design of Yak-141 was plagiarized.
This isn't actually funny in scientific research, not to mention it's more of a reference! Call it taking advantage of someone's misfortune, or some other, less impressive, description. However, they shouldn't underestimate the other side of the sea.
Being able to develop one's own technology by learning from others is also a breakthrough.
The reason they are now able to continuously produce scientific research results is that they are standing on the shoulders of their predecessors, building on the foundation laid by their predecessors' struggles, and extending on this basis. They are not like floating duckweed without roots.
Across the sea, a major breakthrough was indeed made based on the Yak-141.
The advantages and disadvantages of the F135 engine are also very obvious. Its advantage is that it continues the Yak-14, with lift and thrust separated, and extends it to use thrust instead of lift.
The airflow of the engine's lift fan comes from a low-temperature compressor, and the jet is room-temperature air. Therefore, even if it bounces on the ground and is re-inhaled by the engine, it will not cause surge. This largely solves the problem of engine inlet distortion caused by the re-inhalation of high-temperature airflow in the Yak series.
At the same time, it also avoids the complex power conditions and reliability problems of multiple engines on one Yak series aircraft.
Just to achieve the above series of advantages, the structure of engine + drive shaft clutch + fan results in too much space and complex structure. The oversized structure naturally also brings about excessive weight, excessive volume, and excessive engine weight. This vicious cycle leads to the core problem of too small payload and insufficient deterrence.
The tail flow temperature is high. Even though the suckdown effect of the Yak series has been greatly solved, a low-temperature compressor has been added, and the jet has converted the air into room temperature, the tail flame temperature is still as high as over 900 degrees, which still imposes an excessive burning load on the aircraft carrier deck.
Although it will not cause the steel structure of the deck to melt and collapse, it will still cause deformation and damage, and it will be enough to break the heat-resistant concrete of land airports into snow flakes or completely melt the asphalt.
Moreover, in the low-speed mode of vertical take-off and landing, the auxiliary air intake door of the lift fan is easily damaged due to the high wind pressure. This is a shortcoming of the fan.
However, even with so many shortcomings, the F-35B still successfully completed its test flight.
Confidential information shows that in the past two to three years, the F-35 has continuously announced successful test flights and successful research and development, and has announced to the outside world that it will be deployed and put into service one by one in the next two years, bringing great pressure to the entire world.
However, if Wu Tong remembered correctly,
In that future memory, the F-35B crashed more than once, and eventually, the entire F-35 was grounded ten years later.
Wu Tong did not laugh at the other party's arrogance, but she wanted to use it to warn herself that in the subsequent engine optimization, she must avoid the detours taken by the international community and the defects discovered.
Being blindly proud and arrogant, and laughing at others, will sooner or later make you a joke. Wu Tong will not allow himself to make such a low-level mistake!
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