Chapter 122: Modifying the Engine Is Simple

Ha Gong Da, Second Department.

"Why hasn't Qin Miao come back yet!" Zhou Bing paced back and forth in the office.

"News came from Ha Fei that Tuobo Meika Company has already agreed to the plan to improve the Aheye-1 engine, and they will send an engineering team over in the next few days. If we have nothing to show, we'll... lose face! It's fine if we ourselves lose face, but we can't lose face for the people of Ha Gong Da!" said Director Mao of the Materials Department, who was also really anxious.

"Now, talking about this is useless; we should still seize the time, quickly digest all the data on the Aheye-1 engine, so that when we deal with the French, we won't lose face." said Director Luo of the Second Department, who remained calm.

Actually, he was also panicking inside, but he had to hold down the fort and persist until Qin Miao returned.

"All the data have been studied; the French's design is still very advanced. The compressor uses a combination of one-stage axial flow and one-stage centrifugal. The impeller above is made of titanium alloy forgings, CNC machined, with a design speed of fifty thousand rpm. The combustion chamber uses centrifugal oil spraying, and an electron beam creates thirteen thousand tiny holes on the flame tube, forming full-film cooling."

Zhou Bing had of course already finished reading all the data; the senior students in their aircraft engine specialty had already gone through it many times.

This engine's technology is at least two generations ahead of domestic ones!

Ding ding ding...

Just then, hurried footsteps approached from afar.

"Teacher Zhou, Teacher Zhou, Qin Miao is back!"

"He's back? Where?"

"He went back to the dormitory..."

"What dormitory? Go get him over here quickly!"

Half an hour later, Qin Miao, with red-rimmed eyes, appeared in the Second Department's office, and everyone was startled.

"San Shui, what's wrong with you?"

"Just tired."

The development of Air Force equipment is a major matter that can't be changed by his casual remarks; so when he declared that advanced equipment couldn't be bought, the Air Force was shaken, holding meetings for three days straight! Despite the day-and-night turmoil, they still couldn't reach a conclusion.

Qin Miao couldn't wait any longer; he could only say he had to go back, otherwise the French would find out, so they let him return! Moreover, Old Lin specially arranged a plane for him.

He originally thought he could catch some sleep on the plane, but... Old Lin had him write a detailed report to hand over to someone upon landing, so he couldn't rest on the plane either. After finally returning, he still wanted to get a good night's sleep, but the Second Department sent someone to call him over.

"San Shui, we know you're tired, but the French will be here soon, so first tell us your plan; once you've arranged our work, you can go to sleep."

"This is also simple: first, add one more stage to the two-stage compressor basis. The French's aircraft engines have pitifully low pressure ratios; what is the pressure ratio of this Aheye engine?"

"8 to 1," Zhou Ding said offhand.

"At the same time, the T700 engine used on the U. S. Black Hawk helicopter has a pressure ratio of 15!" Qin Miao said: "Such a backward engine must be improved!"

Pressure ratio is the ratio of the compressor's exhaust pressure to its intake pressure; the higher this value, the more air the engine can draw in, and naturally the higher its thermal efficiency.

The Americans' T700 uses six compressor stages to achieve a pressure ratio of 15, while the French simply used two stages, so of course the pressure ratio is low!

The French's Mirage 2000, touted as a godlike fighter, uses an engine that's pretty worthless—the single-rotor M53 has a low pressure ratio and high fuel consumption, earning it the nickname of a turbojet among turbofans.

Now, Qin Miao's first suggestion is to add one more compressor stage!

"This... would probably require a major overhaul of the engine."

"Exactly, so we need the original design data; once we have it, the French can leave if they want, and we'll continue developing it ourselves!"

"Anything else?"

"Also, we could raise the turbine inlet temperature; we have hollow-cooled blade technology, right? Using it, we could easily increase it by fifty degrees, even up to a hundred degrees, which would greatly boost the engine's power."

The principle of an aircraft turbine engine is simple: up front is the compressor, which blows air in; it enters the combustion chamber, where fuel is injected and mixes with the air to burn, forming high-temperature, high-pressure gas that pushes the turbine to rotate; the turbine then drives the front compressor to rotate, forming a closed loop.

After passing through the turbine, if the high-temperature, high-pressure gas is expelled directly backward, it's the simplest turbojet; if a large fan is added in front and a duct casing around it, it becomes a turbofan, which gives greater thrust and better fuel economy.

If a reduction gear is placed in front to drive a propeller, it's a turboprop; if a free turbine is added at the back to convert the high-temperature, high-pressure gas's thrust into shaft power, it's a turboshaft.

To improve the performance of these engines, we need to upgrade the compressor, which can draw in more air and also raise the temperature the turbine can withstand. There's a simple relationship: generally, raising the turbine inlet temperature by 100 °C increases the engine's thrust by twenty percent.

To let the turbine withstand high heat, we need various high-temperature materials and advanced structural design—for example, drilling holes in the turbine to let internal air flow out, forming a cooling film on its surface, which increases heat resistance.

Worldwide, the United States was the first to do this, the East second; to boost the thrust of their own outdated engines, Eastern engineers racked their brains.

We might be lacking in high-temperature alloys, but the entire production technology of the Aheye engine will be transferred to us in the East under the agreement, still using the original metal materials; as long as we improve it according to our own techniques, its performance can be greatly enhanced.

"Anything else?"

"Even if there is more, it's ours, and we definitely can't tell the French!"

"Alright, then we'll contact the relevant units and meanwhile design the engine's improvements ourselves. Qin Miao, you can go rest first; when the French come, you'll need to join us in negotiating cooperation."

"Okay, no problem!"

Qin Miao yawned; he was indeed exhausted, and now he should get a good night's sleep!

Walking onto campus, Qin Miao felt a strange sensation for no reason—the campus was empty and deserted; was it because the weather was cold, so no one was outside? Or…

Returning to his dormitory, Qin Miao saw Chu Miaomiao hugging her books, diligently studying.

"Brother San Shui, I've brought back your meal; eat first, I'll keep studying."

"You... are you having an exam?"

"Yeah, the final exam."