Chapter Thirty-Four: The Great Contract and the Grand Calculation

“Based on the data we finalized yesterday, I’ve reported to the director, and he’s already approved it. In the next few days, everyone can officially start designing.” The large bundle of draft papers used for calculations was placed in the empty corner by the wall.

You’re not mistaken—though the design of an aircraft engine involves intricate calculations, it ought to be aided by computers. However, obtaining a computer at this time is exceedingly difficult. The entire base has only a few DJS-130 series computers, finalized in 1974, with a processing speed barely reaching one million operations per second, still relying on punched tape for input and output.

Despite their limitations, computers are treasured within the base. For a project as unconventional as Yang Hui’s, getting access to them is almost impossible, so their hardware situation is below even the base’s usual average.

Thus, the only option is to deploy a mass manpower approach. Manual calculations are still manageable for these university graduates; if it becomes too much, they can appeal to the director for coordination.

“Team Leader Yang, how do we begin the design? Which part should we start with? The engine shouldn’t have too many components, so designing them one by one should be feasible,” Pan Wen asked, organizing his desk as he settled into his chair.

Yang Hui pondered the best way to proceed with the design. Tackling parts individually would be manageable given the number of team members, but it would take too long—finishing within two or three months would be quite challenging. So he decided to abandon this plan.

The alternative was to split the engine into several modules and assign each to a team member to design. But this would disperse their research efforts. For this approach to be effective, they’d need to mobilize other specialized departments to participate, yet that hadn’t been officially announced by the institute, making implementation difficult.

“I think we should divide the work among everyone. That way, we’ll move faster. Tackling each component together won’t meet our deadlines.”

No matter what, Yang Hui resolved to distribute the tasks, assigning responsibility for each module. If someone needed guidance from a specialized department, that was permissible, since the institute didn’t have much going on at the moment, and finding something to do wasn’t unwelcome.

As for the model aircraft project not being officially announced, he thought the director could simply inform everyone—it wasn’t something that could be kept secret anyway. Within an institute, what secrets could there possibly be? Moreover, the project was only for design; the real risks lay in manufacturing.

Yang Hui’s proposal immediately revealed its weaknesses, chief among them the dispersion of research strength—a problem that was particularly acute for their small project team.

Long Derong was the first to voice concern. “This doesn’t seem ideal. There are only a handful of us, and splitting up would be difficult. Working together might be better.”

You couldn’t blame Long Derong for his conservative thinking. The project was assigned to the team, and the institute hadn’t said they could enlist help from other departments. He simply hadn’t considered that possibility.

“No need to worry about that. Once you receive your assigned sub-project, you can seek help from relevant departments. Since the institute isn’t busy, it's possible to find assistance. I expect the director will inform the other departments for us.”

This assurance addressed everyone’s concerns, and the team nodded in agreement. Being responsible for a single module was preferable to tackling everything together; becoming deeply familiar with one part was a common practice in aircraft engine development. The scope of an engine was simply too broad for any one person to master entirely.

“Should we first establish the interface dimensions for each component? That way, everything can be coordinated once assembled.” Growing up in the base and later studying at university, Zhong Jianshe often got straight to the heart of the matter. The issue of interface dimensions was exactly what Yang Hui had been thinking.

“Yes, we need to finalize these now, then divide the sub-projects accordingly.”

He took a blank sheet of paper to record the dimensions. After splitting the engine components, the sizes would mainly concern shaft and bore connections, keyway fits, and so on. Mortise and tenon connections for impellers were being phased out, with modern high-thrust axial flow engines moving toward integrated impellers; for this less demanding model aircraft engine, integration would suffice. There was no need for so many parts—too much hassle. Both centrifugal and turbine wheels could be integrated.

“Alright, let’s settle the dimensions. The main shaft will face high speeds, leading to high temperatures and thermal expansion. For the two rotating fits, a clearance fit is preferable.”

He nodded, agreeing with the reasoning, though there was no need to get into such detail at this stage. The fine points of tolerances and fits could wait until the manufacturing process was finalized.

“Yes, that’s the voice of experience. Let’s move on—let’s determine the nominal dimensions now; tolerances and fits can be addressed later,” Yang Hui said, not bothering to take notes yet, as it wasn’t necessary to record irrelevant data.

Handing a calculation notebook to Xie Lianfa beside him, he instructed, “Take these specs for maximum thrust and speed across the series, and calculate the required cross-section for SUS304 stainless steel to ensure sufficient strength.”

Upon receiving the task, Xie Lianfa immediately went to his desk to calculate. Engineering calculations aren’t as straightforward as math problems; they require reference tables and consideration of material properties, which vary widely. He picked up his pen and began, his head bent intently—this was the proper atmosphere for a research institute.

“Let’s set that aside for now. Calculating this will take some time. We should move on and discuss other matters—look at the casing, it…”

“Yes, let’s do that.” Yang Hui recorded the data and continued to delve deeper.

“Alright, that’s it. The calculations are done, and the dimensions are here.” He brought over a sheet densely packed with calculations—clearly eager, but the satisfaction of solving a problem is unparalleled, so Xie Lianfa’s excitement was understandable.

Amid a sea of letters and numbers, the final result was easy to spot and verify—engineering errors tend to stand out.

“Good, according to the previous data, this should be correct. But ultimately this shaft will be a stepped one; these figures aren’t quite enough yet. Once the remaining calculations are done, you can use the material's mechanics to finalize the dimensions.”

Seeing the others engrossed in their calculations, and with several sheets of data before him, Xie Lianfa smiled, “Yes, it looks like a stepped shaft—I realized it while calculating.”

“Alright, you can wait for now. I still have some calculations to finish.”

Yang Hui continued his calculations, though he was never as fast as the others; he had sensed this early on. Seeing the others finishing up, he pressed on.

He was the last to finish, though not by much. It was hard not to lament how awkward it was working without a computer—even this small amount of data took so much time.

Computers really do make people lazy; they’re insidious. But if he were handed a computer now, Yang Hui would certainly use it, since it’s the way of the future. Its benefits are too numerous to ignore. The drawbacks are negligible, as it's ultimately about liberating productivity.

After collecting and reviewing all the data for errors, he copied the necessary figures for Xie Lianfa, then continued refining the main shaft data.

“Alright, the basic data is ready. Pan Wen, take these and calculate the position for the fuel inlet on the combustion chamber. Zhong Jianshe, you handle the…”

After assigning tasks, Yang Hui realized he had nothing left to calculate—the key dimensions were either being solved or already done.

Helpless, he sat aside, organizing the completed data for easy reference.