You promised to build cars, so why did you go into the military industry?

"Full-flow staged combustion cycle rocket engine, internal designation 'ZK-131'."

120 tons of thrust at sea level, 131 tons of thrust in vacuum.

In the conference room on the second floor, Guo Shuyan read aloud the report submitted by Lin Yu to everyone in a calm tone.

"Structural mass 800kg, combustion chamber pressure 30MPa, sea level specific impulse 327s, vacuum specific impulse 35..."

Noticing the rather dull atmosphere in the meeting room, Li Ran decided to liven things up.

He tapped on the table, interrupting Guo Shuyan.

He rested his chin on his hands, looked at the crowd, and pondered.

They're veterans who've been through thick and thin with me. Didn't these guys learn the essence of the mixed grain comparison method I used when the Lingyun SU7 was released?

Li Ran, a novice in the field, had some understanding of the data for this full-flow staged combustion cycle rocket engine, but not much.

Such groundbreaking achievements are not easily understood by simply listing dry data!

In the silence, Li Ran spoke:

"This data... I don't understand."

"Why is everyone talking about Xiang Yu being trapped at Gaixia?" Gao Jingming asked instinctively.

"Ha ha ha ha……"

The meeting room was filled with jubilation.

Li Ran didn't know whether to laugh or cry, and looked at Gao Jingming:

"Then let me ask you, what does 120 tons of thrust at sea level mean?"

"If we calculate the gravitational acceleration as 9.8, then 120 tons would be 1176000 Newtons," Gao Jingming replied confidently, flicking his bangs.

Seeing everyone at the meeting nodding in agreement, Li Ran covered his face with his hands, feeling utterly hopeless.

"So, if we assume a car weighs two tons, what does 120 tons mean? 60 cars, right?"

A thrust of 120 tons at sea level—doesn't it make more sense to describe this engine as being able to lift 60 cars?

Li Ran noticed that some of the people present had expressions of sudden realization.

Lin Yu complained:

"Mr. Li, according to your logic, 60 cars are not very intuitive. Why not replace them with 6 steel coils?"

"Are steel coils heavy?" someone in the meeting room asked.

Li Ran looked at Lin Yu with a "see?" expression.

"...It's quite heavy." Lin Yu was speechless. "One steel coil weighs as much as 10 cars..."

"Hahahaha..."

The meeting room was once again filled with a cheerful atmosphere.

"Wouldn't it be much more intuitive to replace a rocket that's thirty or forty meters tall with a fourteen or fifteen-story building?"

"Couldn't 6 mu of land be represented by 5600 football fields?"

"5600 is too many numbers. If we replace it with the Forbidden City, we only need 60."

"Is a head-on collision between two cars at 35 km/h the same as a car crashing into a wall at 70 km/h?"

"Hey! Who said that? Get him out!"

Finding the conversation in the meeting room getting out of control, Li Ran quickly intervened.

Then he asked Lin Yu:

"The report you just gave was very professional, but the data was weak. Let's get straight to the point: compared to the YF-100, is the ZK-131 stronger or weaker?"

"Although I hate to admit it, our engine thrust is slightly less."

The integrated design allows the engine's dead weight to be controlled at only 800kg, making maintenance simple and the price low.

After mass production, controlling the cost to 84 yuan should not be a problem.

"I see." Li Ran stroked his chin noncommittally, then changed the subject, "Has the application to rent the test bench been submitted?"

"Not yet. Inspired by the ZK-131, I am working with Professor Lü to improve the ZK-33 second-stage engine."

The estimated construction time... I'd guess it'll take two months.

January 4, 2013, the Lunar New Year in southern China.

Zhang Chengyuan has led his team back once again.

"Are you still going?" Li Ran asked, looking at Zhang Chengyuan, who looked travel-worn.

"I'm not leaving."

Li Ran patted Zhang Chengyuan on the shoulder:

"I'm inviting everyone over tonight for a welcome-back dinner and a celebration banquet!"

When Professor Lü Chaoping learned that a celebration banquet would be held tonight for Zhang, the elusive manager of United Industries, and his team, he also came over to join in the fun, as he had some free time.

He has an ordinary appearance and is unremarkable.

This was Lü Chaoping's first impression of Zhang Chengyuan.

However, seeing Li Ran solemnly introduce Zhang Chengyuan to the newly joined employees at the banquet, calling his team pillars and heroes, and even taking the initiative to toast him.

It seems this person is not as simple as he appears.

Following the crowd, Lü Chaoping also stepped forward to offer a toast and congratulations.

Silent all night.

After the Spring Festival, when Lü Chaoping returned to the research and development lab, he noticed that there was another figure beside Lin Yu.

"Professor Lü, Happy New Year!" Lin Yu said with a hint of joy. "This is Supervisor Zhang Chengyuan, whom you met before the New Year. He officially joins our team today."

"Professor Lü, Happy New Year!" Zhang Chengyuan stepped forward to shake hands.

Zhang Chengyuan also deeply respected the professor who offered free intensive training courses within the factory.

Rough and powerful.

This was Lü Chaoping's first reaction after shaking hands.

Originally, Lü Chaoping had planned to personally explain the specific technical details of the ZK-131 and the subsequent optimization ideas for the ZK-33 to his new colleagues.

Unexpectedly, this ordinary-looking new colleague was very knowledgeable about technical details and even offered some constructive suggestions.

Could it be that he didn't rest during the Spring Festival holiday?

For a moment, Lü Chaoping was overjoyed and had the idea of ​​taking on a disciple, but he suppressed this emotion considering his own status.

In subsequent work, Lü Chaoping discovered that with Zhang Chengyuan's involvement, the optimization progress of 'ZK-33' was even faster than expected.

"After the pre-combustion chamber is ignited, the pressure in both pre-combustion chambers will rise rapidly, the turbine pressure ratio will decrease, and the turbine output power will decrease, resulting in a decrease in the outlet pressure and speed of the dual pumps."

After ignition in the combustion chamber, the methane path takes longer to reach equilibrium than the liquid oxygen path due to its structure, including cooling channels.

After ignition in the combustion chamber, the pressure ratios of the fuel turbine and the oxidizer turbine change differently, causing the mixture ratio to deviate...

As Zhang Chengyuan stood on the podium, explaining the working characteristics and precautions of the full-flow afterburning cycle engine to the engineers in the intensive training class, Lü Chaoping, sitting in the corner, nodded repeatedly while drinking water.

At the end of March, the latest versions of the 'ZK-131' and 'ZK-33' prototypes officially rolled off the production line.

Subsequently, with Professor Lü Chaoping's introduction, Wang Bing contacted a company with military qualifications called Yilu Pingan Fafafa Large-Scale Transportation and Logistics Company and signed a transportation contract.

They will deliver the two sealed "valuable items" to Factory 627 in the Qilian Mountains within a week.

Lin Yu, who couldn't wait, followed along and carried a camera to film the whole way.

The two delicate and valuable items were not very large, so there were no instances of dismantling lights or signs along the way.

After the filming ended, Lin Yu felt deeply regretful about it.

The people waiting at Factory 627 noticed Lin Yu's regretful expression. Knowing his temperament well, Li Ran stepped forward, put her arm around his shoulder, and whispered:

"Next time we deliver a rocket, I'll have you escort the truck again."

Forget about lights and signs, even toll booths might be demolished.

You'll have to write this down carefully when the time comes.