Chapter 85 The surge position can be calculated!
After Yan Zhongcheng waved his hand to continue working, the people around him finally dispersed and returned to their working positions.
Then he stood there and rested for almost half a minute before he finally recovered from the lack of blood supply just now.
"call--"
Yan Zhongcheng took a long breath, then picked up the thermos cup next to him and took a sip of strong tea, and then prepared to join his men in the next stage of work.
The result is at this time.
Following a rush of footsteps, a figure rushed in from outside the office.
"I found it!"
Yan Zhongcheng, who had just regained his composure, was still thinking a little slowly. He stood there stunned for a few seconds before he realized that the man waving a few pieces of paper was Chang Haonan.
Others who were immersed in work were also attracted by this sudden sound and turned their heads.
"What did you find?"
Chang Haonan took a few breaths before handing the calculation results to Yan Zhongcheng at the table:
“I calculated the theoretically earliest location where flow separation occurs, on the blades of the secondary rotor of the high-pressure compressor!”
!!!
After hearing this sentence, the first reaction of most people in the room was to be confused——
Chang Haonan was not with them just now, nor did he take away the test flight data related to the engine. There was no condition for surge analysis at all?
"Figure it out?"
Yan Zhongcheng reacted the fastest. He quickly took the pieces of paper from Chang Haonan's hand and put on the glasses he had just taken off.
However, he only saw the first page and showed a shocked expression.
"You...you simulated the process of this surge failure forward?"
"Yes." Chang Haonan nodded and continued to explain:
“According to my calculations, when the accident occurred, flow separation occurred first in the secondary rotor blades of the high-pressure compressor, and then quickly spread to the entire high-pressure compressor, inducing axial low-frequency oscillation of the airflow in the rear combustion chamber and turbine. Finally, it affects the low-pressure compressor section in front.”
Yan Zhongcheng didn't answer, he just lowered his head and continued to look at the calculation results in his hands.
Of course he can understand these things on the paper.
In other words, if it weren't for a driving monster like Chang Haonan, Yan Zhongcheng would be the person with the deepest understanding of turbine engine performance digital simulation technology in China at this point in time.
none of them.
When he studied in the UK more than ten years ago, he did research in this direction.
He even developed a modular turbine engine steady-state and transient performance simulation tool with his mentor, which was at the absolute top level at the time and was even used by some research institutions for version updates to this day.
However, in China in the early 80s, there was no foundation in this area at all. Therefore, after Yan Zhongcheng returned to China, he still took over the overall design work of 606 Institute and was unable to continue exploring in the field he was good at.
In other words, the reason why he was able to return to China so easily was because the other party saw that his greatest ability was impossible to display in China at that time.
That's why we didn't block it too much.
By the time some conditions were finally met in the mid-90s, Yan Zhongcheng had not been exposed to related technologies for more than ten years. If he wanted to pick them up again, it would be almost like starting from scratch.
Despite this, his knowledge base is still there after all.
Therefore, when Yan Zhongcheng saw Chang Haonan's simulation calculation ideas, what was once engraved in his DNA was instantly inspired.
To put it simply, the whole night's work he led the engineers from the 606 Institute involved backward analysis of the working conditions when the fault occurred, given the known fault symptoms.
Chang Haonan's simulation uses the flight conditions of the aircraft and the structure of the engine to forwardly calculate where the "weakest part" of the compressor is in the process from normal operating state to surge state.
Although it seems that both methods can find the location that induces surge, the efficiency of the two methods and their help in understanding the root cause of the fault are simply not the same!
There was silence in the entire office, except for the sound of Yan Zhongcheng turning papers from time to time.
After about twenty minutes, he finally read all the contents on the few pages in his hand.
The calculation process is perfect.
Then all that remains is result verification.
As long as the position calculated by Chang Haonan matches the working condition of point O he found on the oscillation ring, it means that it is the correct answer!
At this time, Yan Zhongcheng was very glad that he had not relaxed at work in the past night.
Otherwise, if a young newcomer comes up with the results and they don't know anything about it, it would be shameless.
"Let's put aside the work at hand first and verify whether the working conditions of the secondary rotor of the high-pressure compressor are consistent with the O point we just found!"
After hearing Yan Zhongcheng's voice, other people in the room just woke up from a dream and quickly returned to work.
Although they still don't know what Chang Haonan brought, judging from the performance of Yan Zhongcheng on the opposite side, it must be very important in solving this problem.
Time passed by minute by minute.
Yan Zhongcheng's heart is very complicated.
If there are no problems with Chang Haonan's calculation process and results, it will not only be equivalent to finding the problem, but it can even be used directly to guide the subsequent improvement work of the engine, so as to have the same effect.
But on the other hand, this also means that the compressor design of the turbojet 14 is flawed.
Because if manufacturing defects cause surge, then the results obtained by simulation methods will definitely not match up.
Knowing a result to verify is essentially equivalent to the answer, and the workload and difficulty of the work are naturally much smaller.
Therefore Yan Zhongcheng did not wait too long.
"Gong Yan, we are absolutely right. It is indeed a problem with the secondary high-pressure rotor!"
An engineer pointed at two data curves on the computer screen that almost overlapped and said excitedly.
The whole room was in an uproar.
"Can...really be able to figure it out?"
"So, he ran out to find a place to do calculation simulations last night?"
"Compared to this...he directly analyzed the cause of the fault in just one night. This is the most outrageous..."
"..."
On the other side, Yan Zhongcheng took a long breath after hearing the result.
It's like an exam.
Waiting for results is often more painful than knowing that you did not do well on the test.
Anyway, there is finally a definite result.
The next step is to calm down and start preparing for improvements to the compressor.
"Xiao Chang, this time, you are really our hero!"
Yan Zhongcheng held Chang Haonan's hand with a tired look on his face:
"Go and rest first, there is still a lot of work to do later."
