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

The elders sitting below are all professionals who have been involved in the obscure field of bearings for more than ten years or more. After listening to Chang Haonan’s introduction to the research plan, although he felt that the latter’s goal was a bit too high. High, but I still approve of the plan itself.

In addition to the clear and logical theoretical analysis and the official identity of the chief designer of the Taihang engine, a considerable part of the reason for this is that even if a few people have not used it, they have at least seen TORCH Multiphysics, which is led by him. developed software.

If someone else brazenly said here that they wanted to use numerical calculations to establish a dynamic model of a flexible asymmetric rotor system with complex structural support for nonlinearity under large external overload conditions, they would probably only receive a few laughs.

But Chang Haonan is different.

Although on the surface, his main achievements so far are concentrated in fluid mechanics, structural mechanics and control theory, if we really summarize his results, the common ground is actually in the field of computational mathematics.

There may still be disagreements in the mathematics community about whether this thing counts as fundamentalist "mathematical research", but engineering people don't pay attention to this, as long as it is easy to use.

Chang Haonan could naturally see that the people sitting below didn't quite believe his claim of increasing the life of the bearings tenfold.

In fact, the figure of ten times was still a conservative estimate made by him because he was worried about scaring these people, but now it seems that it is not conservative enough.

But it doesn't matter, the results will speak for themselves.

People in the late 90s really knew nothing about the power of advanced optimization algorithms.

Of course, to ultimately achieve this goal, it is certainly not enough to simply improve the way bearings are designed.

In fact, after determining the bearing structure, he still needs newer, or more adaptable materials and processes.

At present, the bearing steel used in China is mainly ordinary bearing steel GCr15 and a small amount of molybdenum series steel M50. In this regard, it is no different from developed countries. Naturally, the latter is the main source of expensive aero engines.

However, although the room temperature hardness of M50 steel can reach HRC62 and has good hot hardness, and can work continuously and normally at up to 316c, its fracture toughness is very poor, and its dn value is difficult to exceed 2.4x106mm.r/min, which reflects Because the bearing surface has insufficient anti-flaking ability, it is easy to cause irreversible damage under certain extreme working conditions.

This is also the reason why most aerospace bearings eventually expire.

How to improve the idea? It’s easy to say. Any graduate student who is engaged in metal materials can explain it clearly——

Reduce carbon, increase nickel, maybe increase nitrogen, surface harden...

But just having an idea is not enough. You also need to determine how much carbon to reduce, how much nickel to add, how to harden, what process to use, and what coating material to use...

This is why the raw material everyone uses is M50, but the aircraft engine bearings made by Pratt & Whitney, Rolls-Royce and General Motors have longer life and better stability.

All these details can only be determined according to the specific parameters and needs of the bearing parts after the detailed design plan is released.

As for how to determine...

In the past, it could only rely on trial and error, relying heavily on the experience of materials engineers and, of course, luck. The investment required was naturally extremely staggering.

But now, Chang Haonan can give them at least some guidance.

Efficiency is naturally different.

"There's a long way to go..."

Chang Haonan closed the notebook filled with research plans in front of him, looked at the backs of several other people getting up and leaving the conference room, and muttered to himself.

……

As a person who has lived a new life, Chang Haonan naturally sees problems with the China Aviation Industry in the late 90s, but for people who are living in the present, the changes that have occurred in the past year or so can be used as miracles. to describe.

Hao Jing, Yan Liang.

The fourth prototype of the MA-60 and the second full prototype is parked on the tarmac.

A group of people in suits were gathered around the right engine of the plane.

Different from the common yellow or metallic colors of other prototype aircraft, this aircraft is painted with a blue and white paint for the first time today.

Those with sharp eyes will also notice that a trapezoidal flag symbol with red, blue and white intervals is painted on the vertical tail of the aircraft.

Thailand flag.

Obviously, this painting is very targeted.

"Mr. Jonjit, this is our latest regional passenger aircraft, MA60-100, which is also the basic model of the entire series. It can accommodate 60 passengers in normal layout."

A staff member from China Aviation Technology translated into Thai what Gao Quan, general manager of Haojing Aircraft Company, said about the aircraft.

"Like several other regional airliners of this level, the MA-60 currently uses the PW127J series turboprop engine produced by Pratt & Whitney. There is no difference in performance and working mode, but in terms of supporting propellers, we use The self-developed 6-blade composite propeller with higher propulsion efficiency and safety, combined with the new wing with a large aspect ratio, can save an additional 8% in fuel consumption."

When he heard this, the Thai manager named Jonjit's eyes lit up.

In fact, his trip was to seek a batch of new light regional jets for Bangkok Airways.

尽管曼谷航空以泰国首都冠名，听上去好像很厉害的样子，但其实只不过是个成立十年多点的超小规模航司，目前为止仅有8架机龄已逾20年的肖特330客机和14架稍新一些的ATR72-200型客机。

Originally, according to the plan, they were going to purchase a batch of Airbus A320s to upgrade their fleet, but the decision was made in mid-August 1997. Even a fool could feel that the economic situation in Southeast Asia was not quite right, so the management acted decisively. There has been a wave of consumption downgrades, turning the four mainline airliners in the original purchase plan into six regional airliners with 8-4 seats.

Logically speaking, there are not many choices for aircraft of this level. Considering that Bombardier's latest 8-400 is still a piece of cake, even the prototype has not yet rolled off the production line, and the 8-300 is already nearly ten years old. If the aircraft is an old model from two years ago, the only remaining option should be to continue purchasing the new generation ATR72, which is the ATR72-500 aircraft.

However, the importance of advertising is reflected at this time——

The excellent performance of the MA60 at the Paris Air Show gave Bangkok Airways management a moment of hesitation.

China Aviation Industry is basically very transparent in the field of civil aircraft, but AgustaWestland is an Italian company after all, so it is still somewhat convincing.

Moreover, it was also during the air show that China promoted overwhelmingly that they had reached mutual recognition of the airworthiness of regional aircraft with the European Union. Later, news came out that they had reached a similar agreement with the United States.

These two things played a decisive role in improving the confidence of foreign users.

More importantly, although the price of MA60 is only slightly lower than that of ATR72, considering that China and Thailand are neighboring countries, after-sales service is definitely much cheaper and more convenient than ATR.

As a result, Bangkok Airways' board of directors finally decided by one vote to give the new model a chance.

For China, this purchasing intention from Thailand is a complete surprise.

Although Chang Haonan has reached mutual recognition agreements with Europe and the United States on the airworthiness of regional aircraft through some showy maneuvers, even he himself actually has the idea of ​​​​fighting for the future.

Passenger aircraft still need a bit of word-of-mouth accumulation.

At least in the first two or three years, domestic airlines were still the main operators.

Chang Haonan has even thought about integrating several airlines that are relatively suitable for operating short-distance regional aircraft, such as Beijiang Airlines and Qian Airlines, into United Airlines in the airline integration plan that will be submitted soon, even if it is a loss. We will continue to operate MA60.

As a result, domestic users have not yet arrived, and the first ones to come to our door are foreign customers.

It’s no wonder that General Manager Gao Quan has put down many things but still has to personally take charge of the reception.

Six aircraft are just small shrimps for Boeing and Airbus, but for China Aviation Industry, it is a complete milestone.

"Can I go inside the cabin and have a look?"

Jungjit raised his head and glanced at the fuselage.

The Chinese people specially painted this prototype with their company's livery, which is undoubtedly a sign of sincerity.

"Of course, come this way, the ramp truck will be here soon."

Gao Quan was obviously prepared. He picked up the walkie-talkie and said a few words, and a ramp car slowly drove over from a short distance away.

Due to the limitations of the original structure, the cabin doors on both sides of the MA-60 are set at the tail, making it shorter than the other two regional turboprop airliners. Even passengers with a height of about 1 meters need to bend down. Go in.

It's a minor disadvantage.

However, the environment inside the cabin made Jonjit quickly forget about the little unhappiness he had just experienced.