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

Unsurprisingly, this doctoral thesis defense went off track right from the start, completely deviating from the preset schedule and lasted until noon, when everyone was still reluctant to leave.

In fact, if Chang Haonan hadn't forced the discussion back to the main topic, the discussion would probably have continued until sunset.

However, this morning was not wasted.

Yang Liang's own research is of course still at a very early stage, but the inspiration it brought to Chang Haonan is quite valuable.

If he hadn't learned from Zhou Shuwan that the other party had already found a good teaching position at Jincheng Aerospace University, he would have even thought about poaching him.

Although three-dimensional coordinate measurement technology was born out of the needs of the aircraft assembly industry, it can actually play a vital role in the production and manufacturing process of all complex mechanical products.

For example, aircraft engines.

Moreover, since the physical size and weight of the aircraft engine are relatively small, the requirements for hardware equipment such as industrial robots, laser trackers, and digital photogrammetry systems are not as stringent.

It complies with the general principle of starting from easy to difficult and proceeding step by step...

Well, these are all excuses.

In fact, the expected future aircraft engine production capacity is a bit high, and it is very likely that multiple sub-models will be produced on mixed lines, so he wants to expand production as soon as possible...

After the video conference ended, Chang Haonan was not idle either. Instead, he quickly took out a notebook and prepared to organize the content he had just recorded.

However, just as he started writing, he heard hurried footsteps coming from the corridor outside the office.

A few seconds later, Zhang Zhenhua appeared outside the office door.

Chang Haonan raised his eyelids slightly and glanced towards the door.

But he did not stop writing:

"Lao Zhang, why are you in such a hurry?"

As the second-in-command of the Gaofa Group and one of the deputy chief designers of the AE1500/WS-20 project, Zhang Zhenhua naturally has the authority to meet with Chang Haonan.

But everyone is very busy at work, so communication is usually done through phone calls.

It's rare to come directly to your door like this.

Zhang Zhenhua outside the door calmed down his breathing a little:

"Boss Chang, Nanzheng has already transferred the engine pods for the Y-9 transport aircraft to us!"

The sudden news finally made Chang Haonan stop what he was doing.

He put down his pen and looked up at the other person:

“Has it been delivered?”

Zhang Zhenhua nodded:

"According to your previous instructions, the logistics and transportation team sent it directly to the No. 2 test workshop. The technical team is conducting an acceptance inspection. Of course, your signature is required in the end..."

This time, Chang Haonan could no longer sit still.

Although the WS-20 nominally uses the core engine of the WS-10, a set of intercooling devices for improving thermal efficiency are designed on the stator blades before entering the combustion chamber. Therefore, the design of the entire high-pressure compressor is actually quite different from that of the WS-10.

Not to mention that such large-sized titanium alloy hollow fan blades are also used for the first time on an aircraft engine designed and produced by China.

Over the past month, the four parts of the fan, compressor, combustion chamber and turbine, which have completed component-level assembly, have each undergone their own startup and basic performance testing.

Two of the hot end components are not much different from those on the WS-10, so they have now entered the reliability and life verification stage.

However, for the fan and compressor, it is also necessary to combine the two and install them in the engine nacelle to further verify the efficiency and stability of the entire boost assembly under conditions close to actual conditions.

Therefore, he hesitated for less than half a second:

"Let's go to the workshop and take a look..."

……

The aero engine is one of the most core components of an aircraft, so the delivery of the engine nacelle was naturally carried out by Liang Shaoxiu, the chief designer of the Y-9.

In fact, he had been staying in Haojing for quite a long time.

Although the Nanzheng-based Qinfei Group has made some achievements in the field of special aircraft and transport aircraft by taking advantage of the favorable conditions in recent years, this does not seem to have improved its position in the aviation industry.

Instead, it made the superiors decide earlier to bring Qin Fei and Gao Fei back together again.

Liang Shaoxiu, who holds positions on both sides, seems to have naturally become the direct promoter of this matter.

"Lao Liang."

As soon as Chang Haonan entered the door, he saw Liang Shaoxiu, who was standing near the flatbed tray, directing technicians to carry out the transportation.

But almost in the next moment, his eyes were attracted by the pale yellow engine nacelle in mid-air.

Although the AE1500/WS-20 is just an "ordinary" high bypass ratio engine with a thrust of 14 tons, it is a product developed by Chang Haonan targeting the future market after 2010, and its design is quite forward-looking.

To put it simply, it is equipped with an oversized fan with a diameter of two meters.

This also makes the Y-9's engine nacelle the largest product of its type ever produced in the history of China's aviation industry.

Moreover, compared with the C808 and C909, which adopt the traditional upper and lower symmetrical design, another innovation of the Y-9 is that the leading edge plane of its nacelle lip is not perpendicular to the axis of the air inlet, but forms an intersecting one.

This design allows the upper lip of the nacelle to extend forward, which can reduce the actual angle of attack of the oncoming airflow toward the lower lip to a certain extent, and delay the occurrence of separation within the lower lip, thereby improving the performance of the nacelle inlet at large angles of attack.

However, as a price, the staggered angle will also cause separation areas to form on some areas of the nacelle surface, complicating the flow state of the entire air inlet area and placing higher demands on the design level of the entire compressor part.

After some routine greetings, Chang Haonan quickly began to direct the acceptance work.

"The whole production process went smoothly, right?"

While checking the items on the form one by one, he asked Liang Shaoxiu.

Originally, this could only be considered as a starting point for the topic.

But the latter hesitated for a moment, then shook his head:

"To be honest, it didn't go very well."

This kind of answer rarely appears in Chang Haonan's answer.

So much so that he was even a little curious:

"What are the details?"

Liang Shaoxiu replied:

"Other parts are actually fine, it's mainly the lips."

He pointed the antenna of the intercom in his hand at the nacelle that was fixed on the auxiliary hanger:

"This is an asymmetric large-size deep cavity structure. When we produced the engine nacelle for the C909 before, we used the process route of drop hammer forming and then welding."

"However, the Y-9 has greater restrictions on the structural weight, and the wall thickness of the lip part is correspondingly thinner. On the one hand, the old process has too much springback after forming, and on the other hand, it is difficult to avoid deformation during the subsequent solution-quenching-aging heat treatment process..."

Hearing this, Chang Haonan's heart moved:

"So you first perform solution treatment on the blank and then form it as an integrated whole?"

"Exactly!"

Liang Shaoxiu nodded, but it was hard to tell whether the expression on his face was excitement or worry:

"However, this technology has very high requirements for the pre-stretching of the blank and the precision of the mold itself, so the yield rate is not high at this stage, and it is almost unable to cope with the production needs of larger workpieces, especially those over 3 meters in size."

"3 meters?"

Chang Haonan was immediately shocked and thought to himself, you are more daring than me. You are starting to consider the GE90-level engine in advance. Is that okay?

But the other party then explained:

"We didn't intend to use this size... We asked about it when the First Academy of Aerospace Science and Technology came to Gaojing for exchanges. They said they were planning to develop a new generation of medium-sized carrier rockets that use cryogenic propellants, so they wanted to upgrade the overall process at Factory 211..."

"New rocket or 3 meters in diameter?"

Chang Haonan became interested.

He had previously heard from comrades at the National Space Administration that the development of a new generation of launch vehicles had been put on the agenda.

But after all, it was a matter of another system, so I didn’t ask about it in detail later.

I didn’t expect that more than a year later, the demonstration stage had been completed and implementation had begun.

"3.35 meters, to be exact."

Seeing Chang Haonan so curious, and since he was free anyway, Liang Shaoxiu just told him everything he knew:

"The name during the preliminary research was Long March 2F/H, so I guess the size and purpose are somewhat similar to the current Long March F..."

The former actually wanted to ask something else, but at this time the engine nacelle had already been hoisted and fixed, and was just waiting for the next task.

Therefore, he had to put his curiosity aside, picked up the intercom and took two steps forward:

"Compressors and fans, prepare for docking!"