Chapter 1168 WS-20 Engine Nacelle

Unsurprisingly, the doctoral thesis defense, which started to deviate from the middle, completely deviated from the preset schedule and lasted until noon before ending with everyone still unfinished.

In fact, if Chang Haonan hadn't forcibly returned to the topic in the middle, the discussion might have continued until the sun went down.

However, this morning was not wasted.

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

If he hadn't learned through Zhou Shuwan that the other party had already found a good teaching position at Jincheng University of Aeronautics and Astronautics, he would have even considered poaching——

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

Just like an aircraft engine.

And because 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 photographic measurement systems are correspondingly less stringent.

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

Well, those are all excuses.

In fact, the expected aviation engine production capacity in the future is a bit high, and there is likely to be mixed production of multiple sub-models, so he wants to expand production as soon as possible...

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

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

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

Chang Haonan raised his eyelids slightly and glanced in the direction of the door.

But he didn’t stop writing:

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

As the second-in-command of the Haofa Group and one of the deputy chief designers of the AE1500/Turbofan 20 project, Zhang Zhenhua naturally has the authority to interview Chang Haonan.

But everyone is very busy at work, and communication is usually based on phone calls.

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

Zhang Zhenhua outside the door calmed his breathing slightly:

"Mr. Chang, Nanzheng has transferred the engine pod suitable for the Y-9 transport aircraft to our side!"

The sudden news finally stopped Chang Haonan's movements.

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

"Has it been delivered?"

Zhang Zhenhua nodded:

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

At this time, Chang Haonan could no longer sit still.

Although Turbofan 20 nominally uses the core engine of Turbofan 10, because a set of intercooling devices are designed on the stator blades before entering the combustion chamber to improve thermal efficiency, the design of the entire high-pressure compressor is actually the same as that of Turbofan 10 There is a considerable degree of difference.

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.

In the past month, the four parts of the fan, compressor, combustion chamber and turbine that have completed component-level assembly have undergone their own start-up and basic performance tests.

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

But for the fan and compressor, it is 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 close to actual conditions.

Therefore, he hesitated for less than half a second:

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

…

The aviation engine is one of the core components of an aircraft, so the delivery of the engine nacelle is naturally carried out personally by Liang Shaoxiu, the chief designer of the Yun-9——

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

Although the Qinfei Group located in Nanzheng has taken advantage of the east wind in recent years and made some achievements in the fields of special aircraft and transport aircraft, this does not seem to have improved its position in the aviation industry.

On the contrary, the superiors made up their minds to reunite Qin Fei and Hao Fei earlier.

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

"Old Liang."

As soon as Chang Haonan entered the door, he saw Liang Shaoxiu who was directing the technicians to transfer the flatbed bracket.

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

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

To put it simply, it is an extra-large fan with a diameter of two meters.

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

Moreover, compared with the C808 and C909 that adopt the traditional upper and lower symmetrical design, another innovation of the Yun-9 is that the leading edge plane of the nacelle lip is not perpendicular to the axis of the inlet, but forms a staggered intersection.

This design makes the upper lip of the nacelle extend forward, which can reduce the actual angle of attack of the oncoming airflow to the lower lip to a certain extent, delay the occurrence of separation within the lower lip, and improve the nacelle air inlet during large attacks. corner performance.

However, as a price, the staggered angle will also cause separation areas in some areas of the nacelle surface, which complicates the flow state of the entire air inlet area and puts forward higher requirements for 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 regarded as a way to get to the topic.

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

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

Such an answer does not appear very frequently in Chang Haonan.

So much so that he was even a little curious:

"What specifically?"

Liang Shaoxiu replied:

"Other parts are actually fine, mainly the lips."

He said and pointed to the nacelle that had been fixed on the auxiliary pylon with the antenna of the walkie-talkie in his hand:

"This is an asymmetrical large-sized deep cavity structure. When we produced the engine pod for the C909 before, we used a process route of split drop hammer molding and then tailor welding."

"But Yun 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 molding, and on the other hand, during the subsequent solution-quenching-aging heat treatment process It is also difficult to avoid deformation..."

Hearing this, Chang Haonan's heart moved:

"So you first perform solution treatment on the blank, and then perform integrated integral molding?"

"Exactly!"

Liang Shaoxiu nodded, but the expression on his face couldn't tell whether he was excited or worried:

“It’s just that this technology requires very high precision for the pre-stretching of the blank and the mold itself, so the yield rate at this stage is not high, and it is almost unable to cope with the production needs of larger workpieces, especially those with a size of more than 3 meters.”

"3 meters?"

Chang Haonan was immediately shocked, thinking that you are more daring to think than me, so he began to think about the GE90 engine in advance.

But the other party continued to explain:

"This size is not what we want to use...it was asked by the First Institute of Aerospace Science and Technology when they came to Haojing for exchanges. They said that they were preparing to develop a new generation of medium-sized launch vehicles using low-temperature propellants, so they had to ask the 211 Factory Carry out an overall process upgrade..."

"The new rocket is still 3 meters in diameter?"

Chang Haonan became somewhat interested.

He had heard from comrades at the National Space Administration before 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.

Unexpectedly, more than a year later, the demonstration stage has been completed and implementation has begun.

"To be precise, it's 3.35 meters."

Seeing Chang Haonan being so curious, and considering that he was idle anyway, Liang Shaoxiu just knew everything and said:

"The name of the pre-research over there was called Long March 2F/H, so I guess the size and purpose have some overlap with the current Long March 2F..."

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

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

"Compressor and fan, prepare to connect!"