Dongmei led two girls, Yu Muxue and Liu Muyun, into the living room to meet Liang Yunying and Zhu Jingyuan.
Both girls lowered their heads, but the taller Liu Muyun lowered his head obviously more.
However, Dongmei was nearby and carefully reminded the two of them to raise their heads so that Zhu Jingyuan could see clearly, and then the two of them raised their heads.
Zhu Jingyuan looked at the scene and saw it more clearly than through the glass, and still nodded with satisfaction:
"Okay, everything is good, let's choose a date."
The formal meeting ended quickly, and the officials of the palace were busy with formal ceremonies.
In the late Ming Dynasty in history, legal concubines already had a relatively standardized marriage process, but it was simpler than marrying a real wife.
At the very least, a marriage document must be drawn up, and the ceremony can be considered a marriage.
Only those who are concubines in name but slaves in reality will be very casual.
Just pay money to buy the deed and keep it in the backyard for use. There is no clear etiquette process.
Because Emperor Shizu prohibited people from the Ming Dynasty from being slaves, this situation would no longer happen to the women of the Ming Dynasty.
At the same time, after the Renwu Dynasty, princes and emperors' grandsons before the age of twenty took concubines for the first time. The main reason for choosing a date was not whether it was auspicious, but based on the concubine's menstrual cycle.
Based on the experience of Emperor Shizu and the long-term records and verification of Taiyuan Hospital, doctors in the Ming Dynasty have now basically determined the rules of women's fertile period (ovulation period) and infertility period (safety period).
Princes and grandsons before the age of twenty only have two opportunities a month.
The most important thing when taking a concubine for the first time is to confirm fertility.
Therefore, the concubine-taking ceremony will be held during the concubine's fertile period, and the union will only occur during the concubine's fertile period for at least one year.
If he persists like this with two concubines for a year, and the prince and grandson still have nothing to do, then he is basically useless.
Although I can continue to work hard by taking in two more concubines, even if I give birth to a child later, I will not have the chance to succeed to the throne.
Dongmei, a big girl, left with Zhu Jingyuan's two concubines and went to the small room to inquire about the situation privately.
Liu Muyun's fertile period was coming soon, and it was scheduled for seven days later. Yu Muxue had just passed by, and it was scheduled for twenty-three days later.
Zhu Jingyuan's concubinage matter was an absolute big deal in the country of Dashi.
The imperial concubine Liang Yunying took command personally, and the young girls Dongmei and Chunxiang followed and urged. The whole palace quickly became busy.
Zhu Jingyuan himself doesn't have to worry about these things. After his mother comes, he really doesn't have to worry about the backyard.
The next morning, Zhu Jingyuan got up to eat, did daily training, showered and changed clothes, and then went to the martial arts field in the backyard of the palace.
It was the third day of the fleet's arrival, and it was finally time to meet the people Zhu Jingyuan was most interested in - the craftsmen of Daming Airlines.
Zheng Fuguang, a great engineer, brought a group of craftsmen who were willing to come to the country of food to wait for Zhu Jingyuan in the martial arts field. Of course, they were not practicing martial arts.
But to show Zhu Jingyuan the results of more than one year last year.
There were many wooden boxes around them, and dismantled machines were placed next to them.
There are also two airplanes, a car, and a motorcycle.
When Zheng Fuguang saw Zhu Jingyuan coming, he immediately led his team to salute together:
"See Your Highness."
Zhu Jingyuan walked over quickly, looked at the machines all over the floor, and said with a very happy smile:
"No need to be polite, thank you for your hard work. You have worked hard all the way and over the past year.
"We, the big food country, have nothing, so we can only reward you with more wages."
The scene suddenly burst into laughter.
The craftsmen had all heard Zheng Fuguang introduce Zhu Jingyuan to him. He had a very cheerful and kind personality, and most importantly, he was very generous.
When I saw that it was true today, I first said that I wanted to pay the money. The craftsmen were very happy.
No one dislikes such a boss.
After saying hello, Zheng Fuguang introduced the surrounding machinery to Zhu Jingyuan.
Zheng Fuguang's original major was actually mechanics, and he actually studied drilling part-time.
Although these machines were not designed by Zheng Fuguang, he had a complete understanding of them before coming here.
Zhu Jingyuan first came to the motorcycle and looked down at the wheels.
The engine of this motorcycle is mounted on the wheels.
With the wheel axle as the center and five cylinders surrounding it, it looks like a five-pointed star when viewed from the side.
This is a type of radial engine - a rotary engine.
Zhu Jingyuan asked the craftsmen to set up the wheels and tried to start the engine on the spot.
The engine starts to rotate on the axle, and the cylinder also rotates, taking the wheels with it.
The main shaft is fixed and the cylinder rotates like a windmill, so it is called a rotary engine.
The rotating cylinder can store energy and also function as a flywheel, eliminating the need for a dedicated flywheel.
The cylinder itself rotates at high speed, which is equivalent to its own air cooling, and no special cooling structure is needed.
These characteristics make the structure of the engine itself very simple.
Its application is also very simple and can be installed directly on the wheel without the need for a complicated transmission structure.
The engine directly drives the wheels and directly drags the body forward.
This kind of engine appeared very early, before Zhu Jingyuan recovered his memory.
It seems to be full of advantages, so it was very popular before and after World War I in history.
But it also has two huge drawbacks - sealing and weight.
After Zhu Jingyuan turned off the engine, Zheng Fuguang introduced next to him:
"The power of this rotary engine is 32 horsepower, and the maximum speed of the two-wheeled vehicle... has not been measured.
"No one dares to drive it to its limit. The actual measured maximum speed is 160 kilometers per hour.
"The Ministry of Industry and the Royal Machinery Company produced a similar engine with about 160 horsepower.
"This engine has a simple structure and is easy to install.
“But the oil circuit is difficult to seal and pressurize, and the exhaust gas is also difficult to collect.
“Because these structures are all movable, this severely limits its power to continue to increase.
“At the same time, the greater the number of cylinders, the greater the inertia torque during rotation.
"It's okay to install it on a car, but if it's placed on an airplane, the huge inertia torque will seriously affect the aircraft's control performance.
“When you put it on the ground and start the engine, it will cause the aircraft itself to continuously slide sideways.
"Now, institutions including our Daming Aviation, Daming Flying Machinery, and the Ministry of Industry have basically given up on continuing to develop it.
"The research direction of new engines has turned to the new radial engine you designed."
Zhu Jingyuan nodded lightly:
“This is an inherent problem with the rotary cylinder structure and cannot be completely eradicated.
"It is the excessive pursuit of extreme simplicity in design, which leads to corresponding unsolvable defects.
"So my new radial engine is a relatively compromised design."
Zhu Jingyuan came to a plane while talking.
The structure of this aircraft is completely different from the previous ones. It has only one wing and is a monoplane.
The aircraft abandoned its previous wooden structure and was entirely made of steel and aluminum.
The overall shape is also made according to Zhu Jingyuan's design.
It is almost the same shape as the German F-190D and British Sea Fury fighter jets at the end of World War II.
Zhu Jingyuan took a look at the number of cylinders in the engine at the front of the aircraft:
"This aircraft uses an air-cooled nine-cylinder engine. What is the maximum power it can achieve? What about its speed and range?"
Zheng Fuguang immediately said with emotion:
"The rated power of this one is 400 horsepower, and a 600-horsepower one is also under development.
"The cruising speed is 300 kilometers per hour, the maximum range is 600 kilometers, and the combat radius can be 200 kilometers.
"According to the Governor's Office
The method has strong practical significance, and military styles have begun mass production.
“The most critical thing is the engine, without which none of this would be possible.
"His Highness designed this kind of engine and installed it on the aircraft. It is extremely ingenious, and it has excellent expandability.
“In the future, the increase in engine power will be purely a matter of process upgrades and increasing the number of cylinders.
“It is only a matter of time before the power is increased to 800 horsepower or even 1,000 horsepower in the future.
"At that time, the speed of the aircraft may increase to 400 or even 500 kilometers per hour."
The new radial engine designed by Zhu Jingyuan was the main engine of carrier-based aircraft during World War II.
Compared with the previous rotary-cylinder engine from the World War I era, its appearance does not seem to have changed much. It is still surrounded by a ring of cylinders.
The biggest internal change is that the cylinder no longer rotates on its own, allowing the main shaft in the middle to rotate.
Its shortcomings are also very obvious, and a special cooling method must be designed.
But in front of the aircraft engine is the propeller, and the propeller blows air to cool the engine.
Therefore, if used on an airplane, the convenience is not much different from that of a rotary engine, and it also comes with air cooling.
The advantages are also very obvious. The oil supply, pressurization and exhaust structures are all fixed, making it easy to make and maintain.
The main shaft of the engine is directly connected to the propeller, without any reduction or transmission structure.
The most critical advantage is that the integrally fixed radial engine can be made larger and have more cylinders.
The cylinders can be five, seven, nine, or even two rows of eighteen cylinders, or even four rows of twenty-eight cylinders.
As the subsequent technology matures, a turbocharger structure can be added.
Zhu Jingyuan thought about the engine he had heard of in his previous life, and nodded with a smile:
"It's still conservative. One thousand horsepower is just the starting point, two thousand horsepower is considered mature, and the limit should be more than three thousand horsepower."
Zheng Fuguang and a group of craftsmen were originally very happy, even quite proud.
The engine power increased directly from more than 60 horsepower to 400 horsepower in the past year, an increase of six times.
The key is the performance of the aircraft, which has also been improved dramatically.
Zhu Jingyuan now reminded them that based on the four hundred horsepower, it should be increased by at least five times or even eight times.
This is a bit scary right away.
Zheng Fuguang asked with excitement and surprise:
"Your Highness...two thousand to three thousand horsepower? Can it really be so high?"
Zhu Jingyuan smiled and nodded and said:
"Yes, but it also has limits, similar to the limits of a rotary engine.
“The weight is getting heavier, the mechanical structure is complex, and maintenance is becoming more and more difficult.
"When that time comes, new types of engines will have to replace them.
"Another type of engine with a simpler structure and higher power density..."
That is, a jet engine.
