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

One week later, Yanliang Airport.

It is early autumn now. The autumn wind that blows from the North China Plain to the Guanzhong area is whistling, and the air is inevitably a little chilly.

However, for outdoor work that requires meteorological information, autumn every year is often an excellent time window to catch up on progress.

In his previous life, Chang Haonan was a wind tunnel engineer. He basically traveled between the 29th Base and Huairou Science City and rarely experienced the hardships of field work.

In this life, I have finally made up for it all.

Standing in a multi-functional hangar that had just been completed, Chang Haonan raised his head slightly and looked into the distance at a twin-engine jet transport plane parked not far in front of him.

The plane had not yet completely lost power, and there were still a dozen ground crew members standing around it, obviously it had just landed not long ago.

This Y-90002 prototype, numbered 9, is almost identical to its predecessor in terms of airframe structure and avionics equipment. To some extent, it has realized Liang Shaoxiu's bold statement when he first drew the plan, "the first flight will be a complete version."

The only difference is that the two turbofan engines under the wings of the No. 02 prototype are so large that they are a bit uncoordinated.

It is the twin-engine turbofan 20.

Since the load threshold of medium-sized transport aircraft often depends on the strength of the cargo hold, the maximum paper load capacity of this "full-blooded version" of the Y-90 has not changed compared to the early state when it was equipped with PS9A during its maiden flight, and remains at 23 tons.

However, the maximum take-off weight has increased by more than 10%, from the original 81 tons to 90 tons.

This means more fuel can be carried at full load.

Combined with the new engine that reduces fuel consumption by more than 90% compared to the PS9A, the Y- has an amazing range that should not belong to this size.

Even though the larger diameter engine brings greater resistance, the range at a full load of 25 tons still jumps from a pitiful 2500 km to nearly 4000 km, almost catching up with the European A400M transport aircraft which is also under development.

You should know that the latter's maximum take-off weight is more than 9 times that of the Y-1.5.

Although this is just a pleasing comparison method under specific conditions (the optimal operating range of a turboprop engine is relatively narrow, so when operating conditions deteriorate, the original fuel consumption advantage will be quickly eliminated or even turned into a disadvantage), it still has enough impact at least at the publicity level.

Moreover, reducing the number of engines by two will also significantly reduce the direct maintenance man-hours per flight hour, which is extremely valuable for smaller or less experienced transport aviation forces.

In fact, when the No. 02 prototype was shipped out of the factory a month and a half ago, the second air test version of the turbofan 20102, numbered 20, was already installed under the right wing.

However, the position of Y-9 in China Aviation Industry's model portfolio is not just to replace the old Y-8 and seize the international market.

More importantly, the WS-20 will be used to conduct some technical verification for the real work to come, which is the civilian version of AE1500.

Therefore, if someone with sharp eyes observes carefully, they will find that although the engine pods on the left and right sides of the No. 02 prototype have the same size specifications, the position and number of the openings on the sides are very slightly different...

"Previous test pilots generally reported that the new engine not only has greater thrust, but also has a much faster throttle response than the original PS90A. It is very comfortable to use and requires almost no additional adaptation time."

Liang Shaozheng, the chief designer of the Y-9, stood next to Chang Haonan, walking in circles while introducing the current test flight situation to the latter:

"The only downside is that in bad weather conditions... or more strictly speaking, when flying in high humidity environments such as rain or clouds, you can clearly feel that the noise and vibration amplitude of the new engine is higher than normal, and the fuel consumption will also be correspondingly worse."

"Although the data shows that these are within the fluctuation range specified in the manual, if they are equipped to the troops in batches, it may affect the operational confidence of ordinary pilots. In addition, the huge fluctuations in fuel efficiency will also affect the flexibility of transport mission arrangements."

Taking into account the issue of popularity, the training syllabus does not require most pilots to have a particularly strong sense of self-challenge.

Therefore, compared with the test pilots who dance on the edge of a knife every day, the adaptation period required by combat units after replacing new equipment is significantly longer.

And it is also more affected by the characteristics of the equipment itself.

比如在近些年大量换装三代机的过程中，航空兵部队的原则就是尽量保证用歼10换歼7、用歼11换歼8、再用替下来的歼8换歼6。

Although transport aircraft flying is not as exciting as fighter jets, large-scale equipment replacement is by no means an easy task because the missions it needs to perform are more diverse.

"I know this situation..."

Chang Haonan did not show any surprise, but just nodded calmly:

"The intercooler of the 01 batch WS-20 prototype is integrated on the stator blades, so the air with excessive humidity will condense into large-sized water droplets after passing through and hit the rotor blades further back."

"Although I use iron-based materials to ensure sufficient rigidity and surge margin, it will still affect the service life on the one hand, and increase the weight of the engine on the other hand... Military transport aircraft may not care too much about these, but if we want to use it for civilian purposes in the future, this problem must be overcome..."

Before each military aircraft takes off, professional staff officers will plan the mission, but the routes of civil aircraft are almost fixed.

If the engine's fuel consumption fluctuates too much, then if you encounter a day with high humidity, low temperature, or headwind during the flight, and the extra fuel reserved according to aviation industry practice is not enough to reach the destination, you will be in big trouble.

As they were talking, the two of them had already circled to the left side of the plane.

Several technicians, whose uniforms are obviously different from those of the Aviation Industry Corporation of China, are standing on a maintenance jig, preparing to maintain this new batch of engines numbered 20201, which has just completed its first flight.

Chang Haonan motioned Liang Shaoxiu to come closer, then raised his hand and pointed to the high-pressure compressor behind the fan:

"Although the basic structure of the 02 batch engines has not been modified, a set of condensate control modules has been added in front of the inlet of each of the three intercoolers. If nothing goes wrong, it should be able to significantly improve the situation you just described."

If Mr. Richard Partridge from Rolls-Royce was also present, he would probably be very surprised after hearing this conversation.

Because what Chang Haonan just mentioned lightly was the core problem that he had previously believed was "difficult to solve in aviation engines"...

"So, three cloud-penetrating flights were specially arranged during today's test flight to verify this new... uh... control module?"

Liang Shaoxiu squinted his eyes and looked at it carefully, but because of the distance and the bad angle, he could not directly see the changes in the internal structure of the engine.

With the continuous development of aviation technology, the specialization of aircraft design and aero-engine design has become increasingly higher.

Most people cannot switch between these two routes as seamlessly as Chang Haonan can.

"Academician Chang."

At this moment, a voice accompanied by hurried footsteps sounded from behind the two of them.

It is Zhang Zhenhua, deputy chief designer who is fully responsible for the on-site test flight of the WS-20.

In my hand, I was holding a paper document that I hadn’t even had time to bind:

"The analysis results of this test flight are out, and the performance of the new batch of products... can be said to be completely unexpected."

Liang Shaoxiu, who was a little skeptical just now, couldn't help but open his eyes wide:

"Performance...what exactly do you mean?"

Zhang Zhenhua replied without even raising his head:

"Compared to the right engine that has not been upgraded, the impact force on the No. 75 rotor of the left engine during cloud penetration is reduced by about 90%, thereby reducing the additional vibration amplitude by about %. In addition, the impact of clouds on fuel economy is also significantly different..."

As he spoke, he turned to the next page:

"When operating at maximum thrust, the fuel consumption of the left engine in the clouds is only 107.6% of that in dry air, while the right engine reaches 115.9%. Of course, the difference in this case is not too big... The key is that when operating at cruise thrust, the fuel consumption of the left engine in the clouds is still only 118.1% of that in dry air, while the right engine can reach 141.5%..."

"..."

Liang Shaoxiu walked around behind Zhang Zhenhua with a look of shock on his face and confirmed the contents of the paper with his own eyes:

"But I saw on the blueprint that the two engines only have a very slight difference in the structure of the compressor part?"

"Yes."

Chang Haonan took two steps forward and took the report from Zhang Zhenhua. He explained as he flipped through it:

"The so-called condensate control module is actually not complicated at the mechanical level. It is just an additional condenser combined with three three-way valves. The real core lies in the control program, which needs to ensure that the temperature of the wet air entering the intercooler is lower than the corresponding dew point temperature under the conditions..."

“This control process is certainly more complicated, but it is still several orders of magnitude simpler than directly modifying the intercooler cycle parameters.”

After hearing this, Liang Shaoxiu opened his mouth several times, but in the end, he didn't say a word.

Well, he's an aircraft designer anyway, so all he needs to do is make sure the power is good enough.

After a few minutes of silence, Chang Haonan roughly read through the entire report, then raised his head and looked at Liang Shaoxiu:

"Mr. Liang."

The latter's thoughts were interrupted by this sudden voice:

"exist!"

"I remember that according to the plan, the Y-9 will participate in the Singapore Air Show in February next year?"

Liang Shaoxiu nodded:

"Yes, we are already preparing the relevant materials and are ready to submit them to the air show organizers."

"That's just right."

There was obvious excitement in Chang Haonan's tone:

"Please coordinate with the Aviation Technology Import & Export Corporation and try to get Prototype No. 02 on display."

"In addition, we will also send a full-size model of the WS-20. Remember to leave a conspicuous enough booth next to the aircraft!"