Although he has always attached importance to the big guy who talks with the Saudi side, what Yang Hui has to do now is to prepare to start the wind tunnel test immediately. The model making and theoretical analysis have been completed quickly, which are familiar to these veteran drivers of Beihang University, and Yang Hui is now standing on the side and watching the installation of the model.

For the model installation of the new machine, the back support method is adopted, in fact, it is more vividly called the back hanging type, and there are about three ways to install the wind tunnel model: tail branch, back branch, and ventral branch.

Various methods can be adopted, as long as two conditions are met: the first model can not extend out of the model area of the test section; Second, ensure that the test section is always in the core airflow.

It is enough to install special tools for testing, and different test items have different needs in subtleties, so special tools are needed to control the flow of the wind tunnel.

The wind tunnel test was presided over by Yang Hui and Professor Zhu, and in fact, when the wind tunnel test was actually done, it was the professionals who controlled the wind tunnel. The subtle operation requires a lot of expertise, so that the average aerodynamics researcher cannot operate the wind tunnel, and can only say that he wants to change to that flow range immediately during the test, and then control the personnel to operate it.

"Okay, you guys stay away, now I'm going to start the wind tunnel, this guy doesn't talk at all."

When the idlers arrive at the safe zone, the wind tunnel starts to start. As the huge fan spun up and accelerated, the speed of the airflow soared, and after reaching the top speed, the fan rotation began to level off, and the furious airflow seemed to be under control. At this point, it's time to be able to observe.

If you set the exact speed of the air flow and introduce particles into the air flow that are easy to observe, if you test it directly, you will not be able to see the flow of the air flow.

By adding a specific amount of uniform particulate matter, the flow of air can be observed. Of course, in order to actually obtain the data, it is necessary to use a special camera to film the flow of the air flow, and finally to analyze the test data later.

In the 80s, when information technology was at its infancy, wind tunnel testing had not yet been integrated with computers to simplify testing, so more manual labor was needed now.

With the completion of the first part of the test data collection, Professor Zhu nodded with satisfaction and gestured to the staff in the measurement and control room next to him to carry out the next test.

Wind tunnel testing is considered to have a high risk factor, not only violent winds and most importantly noise. There is the sound of a fan turning and the sound of the wind flowing rapidly, although the wind tunnel is designed and built to reduce noise as much as possible, but sometimes for the sake of performance, the noise has to be endured.

In the actual test, the on-site personnel should wear earplugs. Through prior communication, the most simple and effective gestures are used to communicate the meaning of oneself in the experiment.

Knowing what Professor Zhu meant, the operators inside began to adjust the wind speed again. The fan will not be adjusted, and there is a special wind adjustment device to adjust.

After a simple calculation, the power supply is connected to the stepper motor, and the stepper motor pushes the throttle cone to move, so that the airflow can be precisely controlled. It is almost impossible to precisely change the size of the airflow by controlling the fan, which is the airflow generator of most wind tunnels, which directly produces a huge airflow, and can only be controlled approximately.

The throttle cone moves, the airflow begins to increase further, and when the node is reached, the test starts again, and the wind tunnel test is like this, step by step, there is no room for sloppiness, and there is no room for cutting corners.

Maybe there is a special airflow phenomenon at a node that has not been tested, so there will be such a hidden danger in the actual flight, and it may lead to a huge accident by this special detail one day.

Test step by step until the maximum wind force in the wind tunnel is finally tested, and then if you want to continue testing, then you need to change to a more powerful wind tunnel, such as a supersonic wind tunnel.

The test of the attached surface layer should be done step by step, and the subsonic wind tunnel can not meet the test needs, so put it down first, test other items, and there are more test items yet, the test items of the subsonic wind tunnel are the most, and it is also the most cumbersome.

According to the test arrangement, the first intake test, after the surface layer partition is attached, is the lip, cross-section, throat, and airflow changes of the inlet to the retraction section of the intake, of course, it is necessary to test the flow of the airflow of the left and right intakes when the airflow in the body merges, and so on, and so on, so the new intake changes are not just words.

Yang Hui now continues to do theoretical analysis with a group of graduate students who do theoretical analysis, although Yang Hui now graduated from a bachelor's degree, but later Yang Hui is a graduate student, plus continuous study on the job. And later, by chance, Yang Hui was recommended by the unit to go to Beihang University to continue his studies. These theoretical analyses really didn't bother him.

Now Yang Hui's team is conducting a preliminary analysis of the flow test of the inlet outlet (i.e., the engine intake), but in the analysis, Yang Hui found a problem: according to the current outline of the old version of the pneumatic test regulations, Yang Hui will see how this regulation is not suitable.

The intake tract and the engine belong to two different units, which requires a common agreement on a measurement interface, and both sides use the data measured on this interface to make calculations.

Yang Hui looked at the old version of the test syllabus and had a lot of thoughts, is it time to ask these questions? This is the biggest problem, and if this question is raised, there is no doubt that it will be revised as long as it is beneficial, and the revision of the test specification is quite a big thing, which is to change the regulations that everyone abides by.

There are too many areas involved in a change, which not only has a lot of resistance to change, but also takes a long time. This is intolerable for Yang Hui, think about it or test it in accordance with this specification for the time being, although the old version of the specification has various small defects, but it can still be used.

After the completion of this project, Yang Hui plans to make a statistical count of the specifications that he knows has changed in later generations, and report it to the public, so that the above can pay attention to this problem, and it is best to make a comprehensive revision. This is the best way, Yang Hui alone can't write down the test specifications of later generations, this still has to gather many people to revise it together.

At the same time, Yang Hui also thought of other design test outlines, such as engine design outlines, which may also be reflected.

Yang Hui, who had thought too much about it, was confused, and forced himself not to think too much, just follow the old version. Slowly, Yang Hui adapted to the old version of the specification, and at the same time, when Yang Hui was doing analysis, he added everything he could think of, and tried to improve some as much as possible.

Later, when the analysis results of several people were summarized, the gap came out, and insiders could see at a glance how much gold there was.

Looking at the summarized analysis data, Liu Jun, who was most favored by Professor Zhu, was surprised when he saw Yang Hui's analysis results.

"Team Leader Yang, your analysis seems to be much more detailed than our analysis, especially the test precautions you noted later are very interesting."

Liu Jun's words attracted the attention of the people who also did this theoretical analysis, and they all put down their pens and watched at close range, it seems that this one from the 0011 base has some unique skills, or take a look.

For someone to be surprised by his analyzable results, Yang Hui has no doubt at all, he can naturally see the quality of his own thing at a glance, and now that someone asks it, Yang Hui will not be stingy to answer the question.

"Oh, what's different, tell me about it, I'll explain it for you."