The military-industrial scientific research system of the academic master.

Chapter 1288 Great Strength Creates Miracles

After all, research on rocket boosters is not the focus of the hypersonic weapons project.

Therefore, after assigning the subsequent tasks to Lin Chenggang and Li Yabo, Chang Haonan quickly devoted himself to the research and development of the waverider aircraft itself.

Just as a few people saw Lin Chenggang off, the JF14 wind tunnel had just completed the inspection, maintenance and preparation phase after the last aerodynamic test and was ready to start the next round of testing.

In fact, although the operation of large ultra-high-speed wind tunnels is quite cumbersome, under normal circumstances, it only takes a few hours at most between two starts.

The reason why this time it took almost an entire day was because Chang Haonan was conducting a new multi-physics field composite research.

Therefore, in addition to the normal preparation work, a series of modifications to the wind tunnel model and model support frame are required.

Thanks to the fact that the JF14 was specially built for the hypersonic weapons project, the relevant hardware equipment was reserved in advance.

Otherwise, this kind of functional transformation often takes a week or even longer to complete.

When Chang Haonan and the other two returned to the wind tunnel control room, they ran into Chen Hong, who was wearing a blue-gray work suit:

"Academician Chang, Lao Jiang, I was just about to go to the Computing Center to look for you."

The latter stopped immediately:

"The No. 3 wind tunnel model has been installed, the ionization generator is also ready, and the flow field, temperature field and electromagnetic field sensor tests are normal. It can be started at any time."

Chang Haonan nodded and quickly walked to a computer in the center of the operating table.

Generally speaking, in order to allow operators to directly observe the working conditions inside the wind tunnel, conventional wind tunnels will install a series of cameras around the model.

However, due to the extremely exaggerated working pressure and total airflow temperature, ultra-high-speed wind tunnels are bound to have no conditions for installing optical observation equipment, and the status of the working chamber can only be confirmed through cold sensor data and simulation schematics.

In fact, the No. 3 model used in this test has no essential difference from No. 1 and No. 2 in terms of overall outline. Both are principle models of the standard waverider appearance, not the specific design of any type of hypersonic flying body.

But the inside of the model is a hollow structure that is completely different from the previous two, and a liquid pipeline is introduced through the model support frame below.

At the same time, a series of small holes are set at the top of the waverider head to atomize and spray the pre-prepared ionic liquid.

At this time, a small green dot is displayed next to each device point on the screen, indicating that the entire set of equipment is functioning normally.

"Get ready to start."

The JF14 wind tunnel has been started nearly a hundred times since its initial launch and has long passed the initial unstable stage, so Chang Haonan does not need to pay too much attention to the operation of the equipment itself.

Following his order, the staff who had been ready took their positions, and Chen Hong himself turned the key and turned on the ignition switch of the detonation drive section.

The hydrogen-oxygen mixture is ignited by an electric spark within one thousandth of a second. After multiple superposition and enhancement of the shock wave reflection chamber and the auxiliary detonation section, the detonation wave forms a high-temperature and high-pressure working airflow, which flows into the working chamber loaded with the test model along the Laval nozzle.

Almost at the same time as the detonation wave was generated, the nozzle of the forebody of the aircraft began to eject the reverse ion mist after high-pressure ionization. After encountering the airflow with a speed of up to Mach 12 and a total temperature of 8000K, it pushed the strong bow shock wave that was originally close to the blunt body away from the surface of the object, forming a contact surface, a jet layer and a Mach disk in the middle position, and a large-scale reflow zone was generated near the nozzle outlet, blocking the high-temperature airflow that was enough to melt all metal materials outside the surface of the wind tunnel model...

……

Although JF14 is an advanced wind tunnel with "extra-long experimental time", the effective test cycle corresponding to each start-up is only about 100 milliseconds.

Therefore, for the people in the control room, the only thing they can hear during the entire process is a faint "puff" sound of ignition, and then they can instantly see a large amount of sensor data on the computer screen.

Soon, a series of test results required for this test were sent over from another specialized sensor data processing station.

"Compared to the No. 477.74 model which uses hemispherical support rods for protection, the peak heat flux density of the No. 2 model at the initial moment dropped to 57.4W/cm^260, a decrease of 2%, and the overall wall heat flux density was controlled below W/cm^..."

Jiang Zonglin held a heat flux density map in his hand and reported to Chang Haonan:

"From the distribution of the temperature field, we can see that the low-temperature and low-pressure fluid in the recirculation zone at the head of the flight body covers the surface of the bluff body, which has a good thermal protection effect. On the other hand, the recirculation zone is attached to the head of the bluff body, making its equivalent shape more slender, so the intensity of the bow shock wave generated is weakened, and the pressure and temperature rise behind the wave are quite limited."

"In addition, the flow field monitoring results show that the pressure distribution on the entire flight front body surface has also changed accordingly due to the influence of the incoming flow aerodynamic heating. The aerodynamic dome has formed a local high-pressure area at the leading edge, making the pressure coefficient of the incoming flow stagnation point reach Cp=1.87. The overall aero-thermal coupling effect has reduced the drag coefficient by about 4.4%..."

Looking at the result, which was not the best but definitely on the right track, Chang Haonan finally breathed a sigh of relief:

"This shows that our multi-physics field coupling strategy for hypersonic flight in the atmosphere is correct... at least in terms of direction. As long as we continue to adjust those dimensionless parameters, we can further improve the accuracy of the simulation calculation..."

As the saying goes, sharpening the knife will never make you chop wood.

First, a standard waverider is used to obtain a sufficiently reliable method for calculating the hypersonic flow field. Although this will take a certain amount of extra time, it will save a lot of trouble in the actual design process later.

"What about the electromagnetic shielding of the surface?"

Chang Haonan asked again.

"The current sensors cannot directly test the thickness of the model surface plasma sheath, but through the electromagnetic wave transmitter installed inside the flight body, it can be concluded that the transmittance of the head in the range of 8-10Ghz and the transmittance of the side wall in the range of 27-35Ghz have increased. These are similar to the previous calculations, but..."

At this point, Jiang Zongli's tone showed some hesitation.

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However, he continued quickly:

"But the improvement is still not enough, especially the transmittance of the head, which is only improved by 115% and 87% compared with the results of Model and Model , respectively. It is still difficult for the X-band radar to play the expected detection role..."

This is not surprising.

Chang Haonan did not show much frustration:

"The sheath at the head of the waverider is a thin layer that fits tightly against the outer wall. In the vertical direction, the electron density and the electron collision frequency and other related parameters will have a large gradient change, thus forming a structure similar to a discontinuity surface, which greatly increases the reflection effect. Our ion jet technology mainly weakens the absorption effect of the black barrier, so the effect at the head is indeed weaker."

For a missile with a normal layout, the head is where the guidance radar is located, and a satellite communication antenna is installed on the upper side, corresponding to the two most critical guidance methods, neither of which is indispensable.

Especially the terminal radar imaging guidance has a decisive influence on the hit accuracy.

"So...are you going to use other technologies at the front end of the flying vehicle?"

Jiang Zonglin was only responsible for the wind tunnel test and was actually not aware of Chang Haonan's overall design plan for the entire hypersonic missile.

In his opinion, the internal volume of a waverider or waverider-like aircraft is inherently limited, and it is already fully occupied, making it difficult to insert a complete new system into it.

"That's not necessary."

Chang Haonan took the test results of the electromagnetic wave signal transmission characteristics from the other party and marked a few numbers:

"I choose to work hard to achieve miracles."

"what?"

Jiang Zonglin's head was full of question marks.

Chang Haonan simply waved his hand:

"Increase the ion flux used to weaken the plasma sheath by an order of magnitude!"