Chapter 1174 Financial Support

Across the world in one hour.

Strictly speaking, this is not a new concept.

In the 1990s, the United States proposed the hypersonic cruise missile "Quick Eagle" to replace Tomahawk. The goal was to be able to attack any target within the territory of the main imaginary enemy within one hour.

However, this plan coincided with the abolition of a large number of projects after the end of the Cold War, and ended in an anticlimactic manner after a few failed experiments.

In the last life, what really made this slogan ring around the world was the X51A "Waverider" technology verification aircraft, which was only released in 2007. It was planned to end the ground experiment in 2008 and conduct four test launches starting in 2009, and then officially Consider introducing weaponization.

Of course, the final result is well known——

We're setting up a national hypersonics club, and guess who didn't get the invite?

In short, in 2005, Chang Haonan shouted this slogan in advance, which is undoubtedly very eye-catching.

Especially compared with the previous solutions that always use launch vehicles for delivery, the final product of the waverider-like configuration is a cruise missile with a relatively low sensitivity, but no weak deterrence.

The threshold for use is relatively low.

Of course, even if you just look at Chang Haonan's PPT introduction, you can imagine that product design with this configuration is probably the most difficult of them all.

Seeing that all the five configurations mentioned at the beginning had been introduced, Qiao Chenqing, who had been eager to try it out for a long time, finally couldn't restrain his desire to ask questions and raised his hand almost impatiently——

The big boss had already given him a sample just now, so of course it was not easy for him to speak directly.

"Excuse me."

Chang Haonan has basically finished talking about the most important content. Of course, there is still a lot of space to follow, but due to time constraints, it is impossible to talk about everything in detail.

Therefore, Qiao Chenqing's question just helped him.

"Comrade Haonan, you just introduced a total of three hypersonic flight body configurations with military potential. Of course, the fourth one, whether using rocket power or air-breathing power, is relatively conventional, but the first and The fifth type requires non-ballistic movement within the atmosphere for a long time, which is very different from the traditional ballistic missiles and cruise missiles we are familiar with in the past, so how should it be controlled? "

As the head of the Air Force, he naturally began to consider the issue of weapons combat efficiency.

Hearing this question that was right in his mind, Chang Haonan smiled, and then turned the PPT directly to more than 20 pages later.

"For traditional gliding waveriders, during the process of re-entering the atmosphere, one of the two ballistics shown in the figure is generally chosen. The Sanger ballistic will make multiple jumps at the edge of the atmosphere, while the Qian Xuesen ballistic will Only perform one reentry maneuver, and then perform an unpowered glide at the edge of the atmosphere..."

"But no matter which one, the re-entry and return stage can be divided into the initial re-entry stage, the energy management stage and the final impact stage. Considering the limitations of dynamic pressure, overload and thermal management, it is difficult for a hypersonic flight body to resemble Large-sized airfoils are arranged like conventional aircraft, so it is necessary to control the flight height by changing the angle of attack, and control the flight direction by changing the roll angle..."

"Technically speaking, the simplest way is to use reference trajectory guidance, that is, select a relatively narrow reentry range before the mission is executed, generate a set of standard trajectories in advance as a reference, and finally design a trajectory tracking law to control the reference trajectory Carry out tracking control so that it coincides with the standard trajectory line..."

For today's report, Chang Haonan specially simplified many proper nouns and calculation parts, so Qiao Chenqing quickly understood the contents of the PPT and nodded thoughtfully.

This reference trajectory guidance is essentially similar to the guidance method of ballistic missiles.

They all determine a trajectory in advance and then fly along the preset path.

Essentially, the flying body does not need to know where it is, it only needs to know when to make what action.

If combined with some measurement and control capabilities, the flight trajectory can also be calibrated to improve reentry accuracy.

But... the shortcomings are also obvious.

"Comrade Haonan, you just said that we need to track and control the actual trajectory and reference trajectory of the flying object, but if we want to hit an enemy target, it is impossible to complete this process on the ground... I am afraid the enemy will not cooperate. us?"

Qiao Chenqing continued to ask in a half-joking tone.

"Yes, so this method can only be used in the technical verification stage to improve our understanding and knowledge of the waverider gliding trajectory."

Chang Haonan nodded, and then added:

“Of course, reference trajectory guidance can also be used in the aerospace field. For those spacecraft that exceed the speed of the second universe, it is difficult to solve the overload and heat of direct re-entry into the atmosphere, so multi-stage deceleration can be carried out through the Sanger trajectory... "

"Exceeding the speed of the second universe?"

The other chief who had been silent just now raised his head.

"That's right...for example, this technology may be used when returning from the moon or Mars orbit in the future."

Chang Haonan originally just said it casually, but since someone is really interested in this detail, he is happy to expand on it.

It just so happens that we can impress our superiors about deep space exploration.

If possible, it would be great to do a few re-entry tests with the help of aerospace projects.

But the other party just nodded and did not ask any more questions, but signaled Chang Haonan to continue the previous topic.

The latter then turned a page of PPT:

"In short, for truly practical weapons, it is necessary to adopt a prediction-correction guidance method that does not rely on a specific reference trajectory. Simply put, it is to compare the deviation between the predicted landing point and the theoretical landing point in real time during each guidance cycle, and then correct the angle of attack and roll in real time according to the settlement results."

"However, this method will produce a large number of partial differential equations in the solution process, which not only has high performance requirements for the on-board computer, but also may fail to converge and cause guidance failure... My research group and I have certain technical accumulation and research results in this field, but still More test data is needed to ensure the accuracy and reliability of the solution..."

"As for the last one I just mentioned, because the waverider-like configuration always flies at a relatively low altitude in the atmosphere, its control strategy is similar to that of existing supersonic cruise missiles, but the performance requirements for control hardware such as rudders and motors are relatively stringent, requiring us to make significant improvements in basic capabilities..."

At this time in 2005, China already had a certain research foundation for both the double cone and the traditional waverider. The most Chang Haonan could do was to provide some additional research resources and basic theoretical assistance.

So, he naturally focused his attention on the waverider configuration.

It is also inevitable to say a few good words.

"What about guidance?"

Qiao Chenqing quickly memorized what Chang Haonan had introduced before, and then continued to ask:

"Glide trajectory can also be autonomously guided by a combination of inertial navigation and starlight navigation, but cruise missiles always need to rely on external signals, whether it is a satellite positioning system or radar echo, to find the target. Will high-speed flight in the atmosphere produce blackouts similar to the process of spacecraft re-entering the atmosphere?"

Asking such specific questions often represents real interest.

Chang Haonan was overjoyed, but on the surface he still controlled his expression:

"For hypersonic cruise missiles with relatively low speeds, that is, in the range of 6-8 times the speed of sound, as long as the aerodynamic shape is properly designed, plasma ionization will hardly be stimulated. Just like ordinary cruise missiles, a combination of mid-course satellite guidance and terminal active radar/optical imaging guidance can be used."

"If the speed is further increased, then as you said, it is necessary to consider the shielding of electromagnetic signals by the plasma sheath..."

Because this part of the content involves a lot of specific calculations, it was not left in the PPT.

So Chang Haonan paused for a moment when he said this, and then looked at a security guard not far away:

"Please bring me something to write on..."

The latter quickly brought a whiteboard to Chang Haonan:

"Sorry, Academician Chang, there is no blackboard prepared at Jingxi Hotel..."

Chang Haonan shook his head slightly to indicate that it didn't matter, and then returned to the stage.

"I will try to explain it in a more popular way..."

He showed a somewhat apologetic smile, and then drew a vector diagram of electromagnetic wave transmission on the whiteboard.

"The black barrier we usually talk about is a very broad concept. In fact, the plasma sheath excited by high heat does not absorb all electromagnetic waves indiscriminately, but is non-uniform, dynamic and non-magnetized..."

"The pointed aircraft is different from the blunt aircraft. Its sheath is a layer of structure attached to the side wall of the aircraft. The thickness is only about 2-4 cm, and in the direction perpendicular to the side wall, the electron density and collision frequency have produced a similar discontinuity. Therefore, for millimeter waves with shorter wavelengths and decimeter waves with longer wavelengths, under certain conditions, they can be made to pass through the plasma layer by applying magnetic fields, etc., to achieve satellite or radar guidance..."

"..."

When Chang Haonan talked about the latter part, there were only a few people who were still looking down to take notes.

Most of the audience just watched him write and draw on the whiteboard.

Fortunately, although the process was a bit complicated, the conclusion was indeed very popular.

That is, he had a way to make electromagnetic waves overcome the black barrier.

Those who can sit in this room have more or less been exposed to or understood manned space projects, and know what the black barrier is.

So Chang Haonan's wave is almost a statement that overturns the world view.

But with the previous content and his achievements in the past decade as a foundation, it didn't seem so difficult to accept.

Not long after, a group of leaders actually discussed it in front of Chang Haonan.

Now that the theoretical basis, overall configuration and research direction are already in place, it is obvious that the only thing left for the project to start is the last element -

Money.