Chapter 1180: Terminal Precision Guidance

The overall design of the warhead was the division of labor that Chang Haonan took on on behalf of the Aviation Power Group from the beginning.

Although this task was neither aviation nor power, no one would doubt his ability in the field of aerodynamic design.

Not to mention the powerful First Institute of Aerospace Science and Technology to assist.

So just now, everyone's focus was basically on other parts such as power, guidance, control and test processes.

It was not until the interruption of the Fifth Institute that the topic was brought back to the warhead.

"Sweating cooling..."

The heated atmosphere in the conference room calmed down a little, and many people lowered their heads and began to think again-

The technical term proposed by Chang Haonan is not new.

The cooling fluid first flows through the porous wall and conducts forced convection to transfer heat away, and then forms a dense air film on the surface of the wall to reduce the heat transfer of the high-temperature mainstream to the wall.

If liquid coolant is used in this process, it will be very similar to the sweating heat dissipation process of animals, and sweating cooling is also named from this.

Its characteristic is that it includes both active and passive heat exchange principles. At the same time, the surface air film formed after the cooling fluid seeps out of the porous wall has an excellent bonding effect. Even if only the passive heat insulation effect is considered, it is better than simple air film cooling.

But as a price, sweat cooling requires special porous materials as carriers, and has extremely high requirements for microporous structure, thermal conductivity, processing technology and heat resistance.

Both the design difficulty and cost remain high.

"Academician Chang... Is this a bit of a sledgehammer?"

Li Rongwei asked in a somewhat uncertain tone:

"Sweating cooling is generally used on the tail nozzle of a rocket engine to withstand the gas temperature above 3500K... Our verification missile is only 6-7 times the speed of sound at the end. Even if it is calculated according to the full sea level altitude, the aerodynamic heating should not reach this level, right?"

After saying that, he turned his head and looked at the representative of the Sixth Academy who specialized in this.

The latter, who was suddenly called out, was a little unresponsive at first, but then nodded:

"That's right... From our experience, with current technology, the efficiency of transpiration cooling can reach 12 orders of magnitude at most... It's a bit of a waste to use it in a double cone, and the speed can't even reach Mach 10."

"Moreover, the transpiration cooling of the nozzle part is generally done directly with liquid fuel, so that the vaporized part can be burned directly. If this process is to be implemented in the warhead part, an additional layer of porous material heat protection layer is required as the matrix, and an additional coolant flow channel needs to be designed, which will inevitably affect the overall strength of the double cone..."

From the perspective of project management, the biggest risk of this verification bomb is not how many new technologies are added.

After all, even if there is a problem, as long as the specific cause can be found, the state can be rolled back.

The more deadly risk is that the entire system becomes more and more complicated for some reason.

Once a problem occurs, it may lead to more problems.

Just like a pile of shit code, after fixing the bug, the whole program can't run normally.

Therefore, in the meeting just now, the only thing that increased the complexity of the system was to change the original warhead counterweight to a terminal acceleration engine.

But this is still a relatively independent part. Even if the engine fails to start, it will not affect the previous propulsion system.

And sweat cooling needs to be highly coupled with the power system, which has a relatively high risk. From the performance point of view, it seems that there is no such high heat release requirement.

So the concerns of the two of them are reasonable.

But like the double cone, this was one of the basic plans determined by Chang Haonan from the beginning, and it was obviously impossible to change it because of two sentences:

"I understand your concerns... So I just said that the early air-breathing hypersonic weapons that will be put into use in the future should still return to the traditional passive cooling route." He first gave a relatively positive answer, but then changed the subject:

"But this is a verification bomb after all, not used to play a practical tactical role, so we need to have a certain degree of foresight and consider all possible situations that may arise in the future of the entire project."

"In the future, our hypersonic weapons may use infrared or visible light bands for target guidance, and the biggest disadvantage of the ablative heat protection design is that the ablation products will be on the edge of the gas. It will flow down in the boundary layer, causing boundary layer pollution, and it is very likely to enter the window area of ​​the visual sensor, causing the loss and attenuation of the information being sought. "

"In addition, at a speed of 6-7 Mach, because the thickness and strength of the ionosphere are relatively small, there is a high probability that there is no need to consider the electromagnetic shielding problem, but for future faster flying bodies, it is necessary to actively use ion flow to weaken and modify the plasma sheath wrapped around the outside of the flying body, so that radar waves of specific bands, specific phases and incident angles can pass through the shielding layer and detect the target by radar, which is to some extent similar to the requirements of sweating cooling..."

"..."

Speaking of this, Chang Haonan suddenly stood up, turned off the PPT that was only used for the meeting background, and then opened a new document.

It was a series of dazzling formulas.

Of course, even if everyone here is an expert, it is impossible to understand these contents immediately without preparation.

But everyone can still understand the series of pictures mixed in between the formulas——

Several different types of remote sensing satellites' radar imaging effects of targets such as large ships, cities, ports, and airports.

Obviously, what Chang Haonan refers to as "radar detection" is not simply receiving reflected echoes like early anti-ship missiles, and then picking the largest one and piercing it.

Instead, SAR imaging is used to accurately identify targets within the search range.

It was only then that everyone present suddenly realized that the goal of Academician Chang in front of them was much longer-term than they initially thought...

At least it's not just a matter of tossing out a hypersonic weapon that's fast enough.

After letting everyone digest it for a while, Chang Haonan spoke again:

"Some of the comrades here...especially those from the Aerospace Science and Technology Group may know that in the past few years, I was fortunate enough to participate in the development of imaging algorithms for two remote sensing satellite systems, Ziyuan-2 and Haiyang-1."

"After that, although a new generation of remote sensing satellites are still under development and there is no specific launch timetable, my research team and I have not stopped technical research on image segmentation and target contour tracking."

"So far, we can basically detect large surface ships with special contour features in the ocean background, and identify landmarks or buildings with special shapes in the land background where the terrain is not very complex..."

At this time, someone from below suddenly answered:

"Like the Pentagon?"

This question was obviously a bit clever, but it relaxed the atmosphere of the scene just right.

A happy atmosphere suddenly filled the conference room.

After laughing, Chang Haonan nodded:

"Although this metaphor may not be appropriate, if we only consider it from a technical perspective, it is indeed the most perfect goal..."

There was another burst of laughter that was slightly sparser than before.

“In fact, the more commonly used function of this algorithm may be to accurately identify towers, hangars and runways within an airport, or to identify the most valuable target ships in a port... In addition, if special Ground-penetrating radar can also identify bunkers or warehouses hidden underground.”

He continued in a slightly bewitching tone:

"Of course, the more complex the actual situation is, the greater the amount of calculations required to identify the target. Considering that the terminal period of hypersonic weapons is very short, the missile-borne computer at this stage may not be able to achieve too precise requirements."

"But I believe that one day in the future, we will use this technology..."