Chapter 1403: Blocking the Gate of Infrared Radiation

It took Liu Yongquan a long time to finally convince the other party that this was not a "thoughtful little surprise" he had specially prepared, but a pure accident.

"Didn't you notice anything during the previous testing process?"

Yang Wei found it a little unbelievable.

"This measurement system consisting of a tunable laser array and interferometer is the only one in China. The 606th Institute is still using the most traditional infrared thermometer, which cannot eliminate the interference of surrounding signals. As a result, as you saw just now, everything is connected together and it is impossible to tell which is which."

In fact, indicators such as infrared signal distribution do not require particularly precise measurements. After all, no infrared seeker will accurately aim at a specific piece of your skin.

The main purpose of the 606 Institute spending a huge amount of money to purchase this equipment is to measure plasma distribution.

The infrared signal is just a test.

It was just an accidental discovery that led the two to discover a very mysterious detail.

Yang Wei controlled the mouse to slide repeatedly on the display screen, magnifying the image of the abnormal area to the limit. The depression on the infrared radiation curve was clearly visible, like a sudden canyon split in the data torrent.

He turned and looked at Liu Yongquan, who was lost in thought with his brows almost twisted into a knot.

Seeing that he couldn't come up with a clear answer at the moment, he simply gave the order:

"Let's do interference scans in several other directions first and see what the derived three-dimensional image looks like..."

This new equipment had just been installed not long ago, and Yang Wei had only conducted a few verification tests during the debugging process. Today was the first time it was officially put into use, and sufficient trust had not yet been established.

In other words, in addition to obtaining further data, he also needs to eliminate factors such as faults or random errors.

However, leaving aside metaphysical factors, it is unlikely that problems will arise in new equipment that has just passed acceptance.

Therefore, after the roar of the engine had been intermittent for most of the day, the two finally got the same result as before.

However, this time it was presented in three-dimensional form.

"This position...should correspond to the engine tail nozzle?"

Due to the existence of the tail flame, the end of the coordinate axis is not the end of the aircraft itself, resulting in that even the three-dimensional image is not particularly intuitive.

"Yes."

Liu Yongquan gave an affirmative answer, but quickly corrected himself:

"But strictly speaking, it should be the transition part between the tail nozzle and the main engine. Normally, it should be the third hottest place on the outer layer of the entire aircraft, except for the tail flame and the nozzle. Without afterburner, the plasma surface should be about... 800-850 degrees Celsius. Of course, due to the influence of magnetron, the temperature acting on the material will be lower, but it should also be about 500 degrees Celsius."

At this point, he pointed to the depression on the screen:

"And if this radiation signal directly corresponds to the temperature, then it should only be at the level of 120-150 degrees Celsius..."

For a moment, everyone was silent.

Yang Wei tried his best to recall every detail of the past, and soon thought of a noteworthy point:

"When I went to Yanliang before, I saw the WS-10G being tested on the air platform. I remember that the tail nozzle at that time was bright silver like the WS-10A, not like it is now?"

"The tail nozzle and transition section were re-coated in May last year..."

Liu Yongquan's voice stopped here, and he immediately understood what the other party meant.

Yang Wei also spoke at almost the same time:

“Is it possible that the thermal insulation coating at the joints has been replaced, resulting in an enhanced insulation effect and lower apparent temperature?”

But the former shook his head almost without thinking:

"The reason why we need to change the coating formula is that the old coating cannot adapt to the outer temperature of the turbofan 10G, and the main function of the coating is to prevent thermal corrosion. There is no material that can maintain an outrageous temperature difference of several hundred degrees through a thickness of only one millimeter..."

He touched his bald head and said half-jokingly:

"If this kind of thermal insulation effect can really be achieved, we should call the Materials Institute of the Academy of Sciences right now and ask them to come over overnight to arrange for a new academician title."

Yang Wei didn't respond, but just tapped his fingers unconsciously on the console.

A few minutes later, he spoke again:

"I think that at times like this, we should return to the most traditional approach."

Then he quickly came to the podium:

"Use the contact temperature probe and prepare to restart the test!"

Twenty minutes later, the roar of the engine filled the entire test workshop again.

The only difference is that the device fixed on the robotic arm has changed from a high-end laser array to a simple but almost equally expensive platinum temperature sensor.

This temporarily added link has not been incorporated into the unified testing system. Fortunately, the data from contact temperature measurement is extremely straightforward and does not require any complicated secondary processing.

The readings can be seen directly at the front console.

"1100K."

After a series of warm-ups, the operator's report came through the communication system.

It is equivalent to about 827c, which is similar to what Liu Yongquan just said.

"What the hell..."

Looking at the result, Yang Wei couldn't help but swear.

High temperature, but low infrared signature.

"and many more……"

Liu Yongquan, who had not spoken for a while, suddenly interrupted:

"Turn off the magnetron and plasma generator... and then switch to the laser array and interferometer to scan again."

The engineer at the test station followed the instructions almost mechanically, removing the probe that had just been installed and replacing it with the non-contact measurement equipment.

The light blue glow at the tail of Unit 2003 suddenly became solid. The plasma that was originally diffused on the surface of the fuselage seemed to be gathered by an invisible hand, converging along a specific trajectory towards the tail nozzle, and then disappeared.

This time, of course, there was no need to produce detailed three-dimensional results.

The depression on the two-dimensional result curve is also much shallower than last time.

But if you look closely, you will find that the reason for the lightening is the loss of the high-temperature plasma covering the outer layer, which causes the signal intensity of the surrounding "highlands" to be greatly reduced.

However, the infrared radiation values ​​at the lowest points hardly changed.

“It’s like there’s a gate.”

Yang Wei made a very vivid analogy:

"Block all infrared radiation that exceeds a certain value... or possibly absorb it. After all, your coating is actually under the plasma, and in principle it should not block the upward-emitting signals."

Liu Yongquan seemed to be inspired by this sentence and suddenly turned around to confirm:

"You still think the problem lies with the coating?"

Yang Wei curled his lips:

"It seems that there is no other possibility. You have just ruled out the interference of plasma and magnetron equipment, right..."

Liu Yongquan put his hands behind his back and paced back and forth in the data monitoring room:

"Maybe... I should give the Institute of Aeronautical Materials a call..."