Chapter 546 I come, I see, I am conquered...
Colombo felt that the sentence structure of Gambelli’s sentence was a bit strange, but because the main focus was on the sky, it was not too After thinking about it carefully, he just shook his head and said in a determined tone:
"I have had contact with the Chinese people since two years ago when I was still at Agusta Company. It was also here, but At that time, the object we cooperated with was a propeller airliner, like the ATR72. "I am sure that they did not have such a high technical level at that time."
Gambe. Li looked over with some confusion:
"Well, I know the MA60 is our company's first fixed-wing product, but if their technical level was not good at the time, why should we choose to cooperate?"
As an engineer specializing in the helicopter field, he I can only say that I have a little understanding of the newly established fixed-wing business department in the company.
Specifically, after making sure that the other party's existence would not affect his own status and the resources he obtained, he stopped paying much attention to it.
“The situation is similar to this aircraft. Although everything else is average, its core competitiveness is very strong and it can save about 8% of fuel compared with passenger aircraft of the same class. This is what many airlines dream of.”
As he spoke, Colombo lowered his head again and rubbed his sore neck:
“Furthermore, their technology has advanced very quickly.”
“When I first came to China, when I saw the MA60, it looked very crude, with a lot of shadows of the Soviet An-24 transport aircraft. . ”
“But only half a year later, the other aircraft was completely different. In addition to the fuel economy card, they also installed new propellers and flight control systems. The noise in the cabin has been reduced to the level of an ordinary turbofan airliner."
Hearing this, Gambelli felt that he had grasped the key point:
"In other words, they started from that. Have you started researching propeller noise reduction technology since then?”
However, Colombo shook his head decisively:
"That's not true. The noise reduction principle of MA60 is to control the phase difference of the left and right propellers so that the mid- and low-frequency noises they emit cancel each other out, which is equivalent to some kind of active noise reduction measure. , and it is only effective inside the cabin, and it still sounds very noisy outside.”
“But this is obviously not possible with a helicopter with a normal structure. The main rotor and tail rotor are hard coupled through the transmission mechanism. There is no way to adjust the phase difference, and their noise levels are not at the same level, so they cannot be offset."
"So this time, we must work on the noise sources such as the rotor and the fuselage."< br>
Ganbeli opened his mouth, but was unable to say a word.
Mainly because I really don’t know what to say.
Realizing active noise reduction by adjusting propeller phase difference sounds simple in principle, but anyone with experience in engineering control knows that theory and practice are two different things.
If it is really implemented, it is another matter.
And they actually developed another method of reducing noise from noise sources at almost the same time.
Even until now, he has not fully understood the other party's technical means to achieve low noise...
This is a bit embarrassing to say.
In his mind, Gambelli once again elevated the importance of this cooperation.
If before coming here, his main idea was still the same as before when he faced Bell Company or Westland Company, which was to simply find an enemy to share the risk.
Now, he has begun to regard the other party as his core competitiveness.
The previous investment in MA60 was undoubtedly a gamble.
But both from Colombo's personal perspective and from AgustaWestland's perspective, it now seems that the bet has been won.
As for the former, he relied on the good relationship he achieved with China during this project to promote a higher level of subsequent cooperation between the two parties, and he also found a wife by the way.
As for the latter, the MA60, as a new model provided by a new supplier, has already received a total of more than 20 orders from Thailand and China before it has completed the finalization and certification process. , obviously the future is promising.
If he could replicate his successful experience in the helicopter field...
Thinking of this, Gambelli rubbed his hands almost involuntarily, showing an eager expression.
The Zhi-9WY prototype quickly completed its scheduled two circles around the field and landed on the tarmac again.
Helicopters are different from passenger aircraft. Normal working conditions include loading and unloading cargo or personnel during the engine startup process. Therefore, except for the vicinity of the tail rotor, there is no safe area around the aircraft that is prohibited from entering.
The Dolphin’s ducted tail rotor is even safer.
Therefore, after the helicopter came to a stop and before the pilot shut down the engine, Gambelli quickly ran to Cui Wenxue and Chang Haonan not far away and asked if he could work on the aircraft. In this state, take a closer look.
Although this plane belonged to the Bingfei Group, and theoretically the former should have the final say, he still looked at Chang Haonan standing next to him.
Cui Wenxue can still figure out who is really in charge of this round of cooperation.
Chang Haonan stretched out his hand directly, signaling Gambelli to do whatever he wanted.
The latter was not polite, skillfully opened the cabin door, took out a noise testing device from his bag, and got in alone.
This device can not only measure a simple decibel value, but also analyze the waveform of the sound to determine the proportion of each frequency band in the noise.
About five minutes later, Gambelli, who was sweating all over in the early spring, got out of the cabin again.
The results of the instruments were similar to what his ears heard.
The overall decibel value does not change much, but the annoying pulsing sound is almost completely eliminated.
Most of the noise falls within the higher range of human hearing, which is the sound of the turbine engine itself.
The final result is that this helicopter feels more like a small business jet when working.
This will be more comfortable for passengers inside the cabin.
For people outside the cabin, the propagation distance of high-frequency noise is closer, which will also reduce the impact of low-altitude flying helicopters on ground personnel.
No matter how you look at it, it’s a sure win.
Intellectually, Gambelli already fully understands the value that this technology can bring.
But emotionally, it was still difficult for him to convince himself.
If a new technology has no disadvantages at all compared to existing technologies, it means that it has completely surpassed its times.
But Gambelli just couldn't understand it.
Why Chinese?
He has no prejudice against any country, but this is really not in line with scientific laws.
The Chinese people had almost no achievements worth mentioning in the helicopter field before.
Now come up and dump Wang Zha directly?
"Will this low-noise propeller have any problems with aerodynamic efficiency?"
Gambelli asked this question with extremely complicated emotions.
He didn't even know what answer he was expecting.
On the one hand, he hopes that the opponent's technology will show some shortcomings in at least some other aspect, because this means a "trade-off" rather than an all-round crushing.
But on the other hand, he hoped to get a negative answer, because no matter what, he had decided to apply the new technology to the new helicopter he was planning.
Chang Haonan had already predicted that they would have similar problems.
Because from the perspective of rotor design alone, efficiency and quietness are indeed a pair of contradictory properties. He looked at Liu Hongbo and Guo Jingshan, who were standing not far behind him:
"Show Dr. Gambelli the aircraft's technical manual."
Soon. , a bilingual material in Chinese and English that had been prepared long ago was handed over to Gambelli.
There is even a heart-wrenching comparison between it and the original dolphin.
The data is so detailed that it even includes engine output power curves.
Of course, this is not a temporary production recently, but was used as a promotional material when I participated in the Singapore Air Show.
It’s just that the last few places that placed orders were from small African countries, and they didn’t even look at these things.
I just compared it with the naked eye with the AS365N1 next to it, and then signed and placed the order.
It directly staged an original drama that was forced to death by a fan——
Although the workmanship and lifespan are indeed a bit inferior, it has more functions (armed), better performance (long hover time), and also Cheaper.
What kind of bicycle do you want?
As a professional in the field of helicopter design, Gambelli naturally found the key data directly.
The results are obvious.
While the rotor itself did suffer some damage, the redesigned drivetrain allowed more engine power to be efficiently delivered to the rotor end.
In comparison, the efficiency decrease of about 3% is nothing to mention.
There is no problem even being regarded as a test error.
As an aerospace engineer, Gambelli can certainly see the correlation between these data, and he is by no means just writing it casually to deceive people.
Besides, the test flight just now cannot be fake...
"It's unbelievable..."
"How did you do it?"
Gan Bailey asked directly to Chang Haonan behind him.
This time he also saw that Cui Wenxue was not the one who really made the decision in this cooperation.
It was this young man who had been standing nearby inconspicuously before.
"In general, the flow field characteristics of the rotor and fuselage assembly during flight are first calculated, and the focus is to capture the shock waves and blade tip vortices, because when the rotor vibrates to emit pulse sound, it will also induce these two This flow state is then integrated to obtain the far-field sound pressure characteristics, and the sound field patterns generated by main rotors of different shapes and specifications can be calculated relatively accurately..."
"As for the more specific technology here Regarding the details, our engineers from Torch Group and Bingfei Group will give more detailed explanations after our cooperation is reached."
Chang Haonan's answer is basically equivalent to Bolt saying, As long as you step out your left and right legs in turn, you can win a gold medal in sprinting.
Everyone knows the truth, but obviously not everyone can be as fast as him.
Gambelli also knew that it was impossible to extract someone else’s core technology here, so he turned to a more theoretical question:
"Relying on CFD calculations? How do you ensure the calculation accuracy of unstructured grids?"
After asking, he felt that this question might cause some ambiguity:
"What I mean is It is said that the finite volume method (FVM) can usually only achieve second-order effective accuracy in the field of compressible fluids. In the past, it was definitely enough to calculate aerodynamic efficiency and the like, but if you calculate the sound field according to your idea, the error will definitely be very large. ”
“We do not use FVM for CFD calculations, because it is theoretically impossible for FVM to achieve high-precision numerical formats for unstructured grids”
Chang Haonan replied with a smile.
While the two were talking, members of the Italian delegation who had just retreated to a distance gradually gathered around.
Therefore, he deliberately raised his volume slightly to ensure that others besides Gambelli could hear him.
“In terms of high-precision finite element calculations, there are some specialized techniques used to solve problems such as numerical oscillations or windward physical properties, so calculation accuracy and calculation efficiency can be guaranteed at the same time.”
< br>"This is also the latest research result of our Torch Group in the field of numerical calculation."
While speaking, Chang Haonan turned slightly and glanced at the circle of Italians around him.
Sure enough, the expressions in several of them's eyes changed immediately.
In fact, he had known for a long time that the delegation sent by Italy this time was not only members of the Agusta Company.
The words just mentioned were meant for this group of people.
......
The group stayed in the outfield until lunch time.
When there are foreign guests, even just from the perspective of face, it is impossible to take everyone to eat lunch as usual.
When leaving, Cui Wenxue slowed down a few steps and came to Chang Haonan's side.
“I really didn’t expect that one day we would be able to convince these European guys.”
He had been working in Bingcheng before and had not experienced the negotiation last year, so It’s normal to say that.
Chang Haonan also said in a half-joking tone:
"This time, the Italians can say, 'I came, I saw, I was conquered'..."
Cui Wenxue was stunned for a moment, then realized that this was a play on Caesar's famous saying, and he also laughed. got up.
“However.”
After the brief joke, Chang Haonan said seriously:
“It must be admitted that in traditional industries, especially in the field of processing and manufacturing, they started too quickly. Early on, even if we work hard to catch up, it is almost impossible to completely close the gap in the short term, not to mention patent barriers.”
"So this time, in addition to jointly developing a new model of helicopter, I am also considering expanding the scope and depth of cooperation. At least, I will also bring in several other Italian companies that came with Agusta!"
His time is quite valuable now. It would be a waste if he flew to Haojing just for one thing.
We have come, but we still have to produce some results.
And just as he said to Yan Yongnian two days ago.
Technical blockade can be broken.
The Italians may not be as well-known as Germany and Switzerland in the field of machinery manufacturing, but in fact the level is very high and the scale is second only to Germany in Europe.
So, we can take this opportunity to open a breakthrough among EU countries.
As the general manager of Bingfei Group, Cui Wenxue had never thought about it so deeply before.
But since Chang Haonan is talking about this, he must also express his position:
"Then Mr. Chang, I will report to you the specific situation of the negotiations at any time!"
(End of this chapter)