The next riding shot began, Zhang Tianqi turned over the horse, drove the horse to gallop forward, when there were still twenty meters away from the horizontal line, Zhang Gong shot, a series of ten arrows came out in a row, castrated fast like a meteor flew straight to the red heart, aggressive and silent. As soon as the arrow was shot, the reins were slightly drawn, and the warhorse man stood up and stopped instantly. When the horse's hooves hit the ground, just before the line, one more point will cross the line. The time distance is just right, showing that it is not a one-time achievement.

Turn the horse's head, no longer pay attention to the results of this round, and return with a horse. The officer who was taking the score was speechless in surprise by Zhang Tianqi's hand, and even forgot to report the score. After a while, he reacted, and hurriedly said: "One hundred rings, it's all in again!" Looking at Zhang Tianqi's flowing movements, the examiner's heart was already happy, such a good seedling is simply a rare occurrence in a thousand years, and it is also a kind of happiness for Bokan Military Academy to get such a talent, it seems that this year's combat department can be proud again.

The subsequent assessment was not shocked, perhaps because of Zhang Tianqi's amazing performance before, and it was difficult to show much interest in the later assessment examiners. After this round of assessment, Zhang Tianqi won the first place in this round, and the overall ranking also reached the third place. Another candidate who made it to the top 20 also made it into the top 10.

In the dense jungle in the southwest of Bokan City, in an area designated by the examiner, Zhou Sheng hid alone in a small bush, this shrub was very short, no matter how you looked at it, it couldn't hide a person, and Zhou Sheng was comfortably hidden in it, blending in with the surrounding environment, even if he approached, he couldn't see that there was a person hidden in it.

The sand table deduction of the command department in the military camp of Kanha City is in full swing, and Wang Tong's war games are advancing all the way, just like a textbook to interpret the battle at both ends of the offensive and defensive ends, and the various arms are reasonably allocated, attacking and defending each other, and finally won a complete victory.

It didn't take long for Liang Yu to find Liang Shan from nowhere, and the two of them rushed over panting. Liang Shan's eyes were full of joy when he looked at Liu Yu: "Good apprentice, tell the teacher about the principle of the blower you said, and I will definitely design and manufacture one for you to use in the shortest possible time." This invention of yours is so useful, I have been working hard to enhance the combustion ability, I didn't expect you to succeed, now it's good. ”

"It's like this. Liu Yu explained. Take out a pen and paper and talk as you draw. Liang Shan nodded incessantly, and from time to time put forward his own opinions to supplement some deficiencies in Liu Yu's narrative. Liang Yu also interjected from time to time. In the heated discussion of the three people, the prototype of a blower gradually became clear.

The drawing is painted with a spiral pattern like a snail shell, with a rectangular air outlet at the very end of the spiral, and inside the circular shell, there is a spindle, on which there are six impellers, the impeller and the spindle are not vertical, but have a certain inclination angle so that it is more conducive to cutting the wind, and this angle has to be obtained through experiments.

The challenge now is how to connect the spindle to the round housing. For this reason, Liang Shan thought of the axle of the carriage and designed a part based on the principle of connecting the wheels and axles of the carriage. Because this part carries the weight of the spindle, it is named "bearing".

Now that the design drawings are available, the manufacturing process will begin. The three of them came to the casting room owned by Liang Shan, which was full of all kinds of casting tools and molds. The first step is the making of a mold, which is made with wax in the shape of a blower shell and then wrapped in a special sand, leaving an injection port. The copper ingots are then heated to melt and injected through the injection port. After cooling and solidifying, knock off the sand outside, and a blank is considered to be processed. Finally, it is sanded and polished, and it is ready to use.

The spindle, impeller and bearing were cast in the same way. After the machining of each component was completed, the assembly began, the impeller was fixed on the spindle, the bearing was sleeved on the spindle and then fixed on the housing, and the world's first blower was successfully manufactured. Rotate the spindle and drive the impeller to rotate, and the wind will whine out of the air outlet. The faster you turn, the stronger the wind.

Looking at the successful manufacture of the first blower, the three of them were filled with joy. "Although we have developed it, there is still a lot of room for improvement, and I will continue to improve it so that it can work better for us. Liang Shan said excitedly, "Baby apprentice, you don't want to smelt copper ingots anymore, just accompany me in the next few days to improve this blower." ”

"Okay, teacher. Hearing that there was no need to refine so many copper ingots, Liu Yu's heart couldn't be happier. "Grandpa, what am I doing? Why did you forget me. On the other side, Liang Yu said dissatisfiedly. "How could I have forgotten you, you just finished this work with us. Liang Shan laughed.

In the following time, Liu Yu and the three of them plunged into the casting room in Liangshan, constantly improving the blower.

Stacks of drawings are designed, constantly being revised. From the rough prototype of the design, it has gradually become more refined. The volute-shaped shell is made more and more sleek, and the curvature is more conducive to the flow of wind, so that the resistance of the wind when blowing out of the shell is further reduced, and a higher wind speed is obtained.

The inclination angle of the impeller was also determined, and after repeated trials, an optimal angle was obtained. When the impeller rotates, it is easiest to drive the wind, and does not produce excessive vibration, so as not to affect the stability of the blower.

One of the biggest difficulties encountered is the bearing, the bearing is connected to the shell and the spindle, when the spindle with the impeller rotates, the bearing has been rotating, the friction loss is very strong, even if it is replaced with bronze material, it is difficult to run for a long time to stop. Otherwise, it can be easily damaged. Liu Yu proposed to use higher strength steel to solve the problem, and the effect was not very ideal. The improvement of the bearing was stopped for a while.

Since the problem was not solved, Liang Yu was very upset, so he left the casting room and went out to relax. Walking on the street and watching the prosperous scene of people coming and going, my mood gradually improved. Walking slowly forward, enjoying the scenery along the street, I unconsciously came to the central avenue of Bokan City.

There was a loud noise in the avenue, and it turned out that a huge statue was being built in the central square of Bokan City, and huge granite stones were constantly being transported from the north gate to the central square. Since the stones were so large that it was difficult for horses to pull them alone, a lot of logs were laid at the bottom of the stones.

Workers continued to pick up the logs behind the boulders and put them in front of the boulders, and the boulders slowly moved forward on the logs under the drag of more than a dozen tall horses. When the boulder rolls forward for some distance, the worker picks up the log behind it and places it in front of the boulder. And so on, the boulder kept moving forward.

Looking at the boulder that was constantly advancing, Liang Yu suddenly thought that the extremely heavy boulder could move slowly forward on the log, and if an iron column like a log was placed in the middle of the bearing, would the effect be the same?

Thinking of this, she couldn't care about enjoying the beautiful scenery of Bokan City anymore, and hurried back to the foundry room. Back in the casting room, Liang Shan and Liu Yu were still working hard there. Liang Yu pulled his grandfather and Liu Yu and told him about his discovery in Bokan City. After listening to Liang Yu's narration, Liu Yu's thoughts suddenly became clear, yes, I remember learning in the cave that rolling friction is less than the resistance of sliding friction, why can't I remember. It's really stupid, but fortunately there is Liang Yu's reminder, or I don't know when I will be able to think of it.