Chapter 1310: Fast and slow, far and near combined into one
Half a month later.
A conference room in Huairou Science City.
As soon as Han Chenfeng walked in from the back door, he was stunned by several name tags placed in front of the long conference table.
In addition to several other well-known names in academia and engineering, there are also several very high-level representatives from the military.
Based on the speculation just now, he can basically confirm that today is not just a simple technical meeting, but may also include decision-making parts such as development routes.
Of course, Han Chenfeng is only here to attend, so he has no right to speak. He can just watch the whole process.
A few minutes later, Chang Haonan entered from another door in front of the conference room. However, he did not sit at the head of the conference table where his name tag was placed. Instead, he strolled directly behind the small podium where the computer was placed.
With his appearance, the originally noisy conference room suddenly became quiet.
The only sound left is the sound of the fans dissipating heat from the field equipment.
Xing Muchun, who was following Chang Haonan, sat directly at the front seat on the left, acting as a temporary host.
Of course, he is the host. In fact, there is no pomp and circumstance in this kind of internal meeting, so I just use one sentence as an introduction:
"Everyone, we just spent a while preparing the aerodynamic model, and now the meeting officially begins..."
As soon as he finished speaking, Chang Haonan on the stage pressed the page-turning pen and switched to the first page of PPT.
“Thanks to the commissioning of the new ultra-high-speed wind tunnel and the efforts of all comrades involved in the project, we completed the testing and data collection of several types of waverider standard models two months ahead of schedule, and determined the waverider The body configuration can achieve extremely high hypersonic lift-drag ratio in the atmosphere and adjacent space..."
Everyone sitting below today, including the military representatives, was not a layman, so after a brief opening, he directly showed several dense data charts:
“In addition, in this process, we have also successfully expanded the design freedom of the waverider in the longitudinal and span directions within a certain range through the cone guide theory based on the three-dimensional axisymmetric flow field. The difference between the calculated parameters and the measured results The mean square error is less than 0075, laying the foundation for the next step of specific development of hypersonic aircraft..."
"..."
After summarizing his work, Chang Haonan paused briefly to make sure the audience had no doubts about what he just said.
Then the topic changed and we got to the main topic of today:
"However, although the main data is in line with expectations and meets the basic requirements, it can still be seen that since the principle of the waverider is to prevent the lateral flow of fluid on the lower surface, thereby limiting the high-pressure area below the aircraft, it is equivalent to using shock waves to maintain flight , so different flight conditions, here mainly refers to speed and angle of attack, are extremely sensitive to the shape, and the optimization range is extremely narrow.”
"Take the classic single-stage compression cone-guided waverider as an example. At the design point of 0° angle of attack and speed Ma=12, the flow coefficient is as high as 4.083, and the inviscid maximum lift-to-drag ratio is greater than 3.75, which completely surpasses our expectations. Performance requirements for glide hypersonic missiles ”
"But if the angle of attack is adjusted to -5° and the speed is reduced to Ma=9, although the change is not large, the above two parameters still plummet to 1.970 and 1.85, which will seriously affect the flight trajectory and effective gliding distance. Of course, The opposite is also true. A waverider with a design point at -5° and Ma=9 will have difficulty adapting to the flight conditions of 0° and speed Ma=12..."
When he said this, his tone was quite sad, as if the project could no longer be carried out, which made several military representatives present at the meeting look at each other.
After confirming that his understanding was correct, one of them said hesitantly:
"But Academician Chang, this is what we knew before choosing the waverider..."
"Furthermore, the air-breathing type's superb flight speed and attitude remain relatively stable throughout the entire process. Only the end will turn into a dive. At this time, there is no need for any lift... Although the gliding type is generally decelerating, it will slow down to Mach 9. It’s also at the end, so it won’t affect the actual tactical effectiveness..."
By the end, it was obvious that I felt a little unconfident.
But I really can't think of any problem, let alone why Chang Haonan is dissatisfied with this result.
"Of course, of course..." Chang Haonan raised his hands and then pressed them down, signaling everyone to calm down:
"If we just want to meet the basic needs of a hypersonic weapon, then the current research stage is indeed sufficient. However, even for air-breathing hypersonic weapons, a large part of the range still comes from lift and glide, and it cannot flexibly adjust flight speed and flight attitude. This means that the intended range cannot be significantly adjusted, which has a great impact on the tactical flexibility of the weapon..."
Although as Han Chenfeng had guessed before, Chang Haonan's future goal is to enable aircraft to fly at hypersonic speeds and cross the Pacific or Atlantic within one hour, but this idea is indeed a bit too long-term, and after all, this research is still It was done in the name of weapons, so he chose to obtain further support within the existing framework.
However, the question he just mentioned is by no means groundless.
"Although it is theoretically possible to develop a series of different types of weapons to deal with the ranges of different key targets, the Second Artillery Force is limited in both funding and organizational size. If too many similar but different models are dispersed, , but will lead to insufficient firepower density for specific targets..."
Sure enough, Chang Haonan was quite well prepared.
When he mentioned "insufficient firepower density," several military representatives below showed slightly uneasy expressions.
Although China's equipment development has advanced by leaps and bounds in recent years, concerns about insufficient firepower have long been engraved into the soul of this army...
It was at this time that Chang Haonan gave the solution he had already prepared:
"So, in the past period of time, I have verified a new conjecture..."
He turned the PPT to the next page again.
Above is a schematic diagram of a design that may seem a bit confusing at first glance.
Check out the 16-9 book bar and see the correct version!
However, an expert can quickly see that this is a series of common-base vertebral waveriders designed based on the cone guide theory.
"With the free flow upper surface of the waverider unchanged, the design requirements for different incoming flow Mach numbers can be met only by changing the compression surface, that is, the aerodynamic shape of the lower surface... Of course, this is designed based on the cone guide theory. As a result, it is impossible to provide a uniform compressed air flow for the scramjet engine, but the kiss-cut cone waverider used in the air-breathing scramjet engine is similar in principle..."
"..."
Later, in order to prove the feasibility of this theory, Chang Haonan also demonstrated a relatively complete design calculation method.
However, this is the part that only core technical personnel can understand.
It was not the focus of the military representatives on site.
"Keep the upper surface unchanged and replace the compression surface..."
The Air Force representative was obviously more familiar with this gameplay and was the first to react:
"It's like the kh31P missile switching the seeker according to different bands of the target radar?"
Chang Haonan shook his head:
"It doesn't even need to be as troublesome as replacing an entire warhead... you just need to replace the corresponding compression surface fairing according to the different target distances before launching."
At this moment, everyone understood instantly.
"In other words, you only need to equip one type of basic warhead to adapt to different mission requirements from Taiwan...from 1,000 kilometers to 10,000 kilometers?"
The representative of the Second Artillery Corps sat up straight in an instant.
"Absolutely. Of course, intercontinental weapons require a larger boost stage, so due to cost considerations, it may still be necessary to equip two models, long and near, but the warhead can indeed be combined into one."
Chang Haonan switched to another picture that was rendered and easier to understand:
"In fact, if future ramjet engines can also adapt to a wider range of operating ranges, then they can even design a two-stage waverider for gliding and cruising, that is, using different waveriders in the gliding and cruising stages. By throwing away the fairing midway, the segment waverider can become a cruise segment waverider, thereby achieving free crossing between the atmosphere and adjacent space..."
(End of chapter)