in2ebook Chapter 678 Just a knowledge transporter, not ashamed at all!
Chapter 678 Just a knowledge transporter, not ashamed at all!
"The solution you came up with..." Jiang Xia was about to flatter his seniors.
"Hey! Stop!" Comrade Changnian immediately interrupted him with a smile, and several laughing voices could be heard through the receiver, "It's not something I came up with by myself! Rongpu, Jinshan, and those old guys Rongzhang all racked their brains and put in a lot of effort! It was all done by a group of people!"
A burst of cheerful laughter, tinged with playful banter, immediately came from the other end of the phone.
Hearing these names, so evocative of their era, Jiang Xia felt a surge of emotion. He might not recognize the others, but the one named Rong Zhang was very likely the founder of China's first ultra-high-voltage transmission line.
"Alright, alright, let's not get off topic! Kid, let's get back to the point. What do you think of this method we came up with? Will it work?"
“Uh…” Jiang Xia hesitated for a moment, not immediately drawing a conclusion, “Theoretically, it’s a feasible direction, but the specific effect… still needs to be verified through detailed calculations. Seniors, what core formula did you use when performing optimization calculations? Was it derived from the area ratio before and after the diameter change and the Reynolds number Re?”
Facing experienced professionals, Jiang Xia didn't want to lose face. He unconsciously became rational, frantically searching through his memory for relevant knowledge in fluid mechanics and thermodynamics.
“We didn’t follow that approach entirely,” Comrade Changnian answered frankly. “We mainly estimated the losses based on the core idea of the Kármán-Carnot formula. However, theoretical calculations showed that the velocity change at the change in diameter was still too drastic, resulting in excessive losses, which was not ideal.”
Comrade Changnian paused for a moment before continuing, "That's when I remembered the 'finite element method' you mentioned before! We were wondering if we could apply this idea to the design of the guide cone?"
By designing a multi-segment gradually varying cross-sectional guide cone, what would normally be a sudden, drastic change in flow velocity is broken down into a series of continuously varying micro-units, allowing the flow velocity to transition more smoothly and stably, thus minimizing impact loss!
"That's a good idea!" Jiang Xia nodded. This is the essence of applying the finite element method to fluid optimization!
"However," Comrade Changnian changed the subject, "how exactly should this 'multi-segment infinitesimal element' be precisely expressed through a mathematical model? How should the cone angle and length variation of each segment be set to achieve the optimal effect? We still have some different opinions internally, and there's quite a bit of debate about it."
"Oh, I see..." Jiang Xia suddenly realized, and a knowing smile unconsciously appeared on her lips.
He reached out and gently patted the shoulder of Secretary Liu, who was still struggling with the operating instructions, indicating that he could relax—there was no need to calculate those headache-inducing formulas anymore.
聪明的读者老爷肯定早就发现了，江夏之前甩给小刘秘书的那一串天书般的公式：Δh=(1?A1/A2)^2*c1^2/2、Δh=K?c2^2/2、c实际=m˙/p?A中……拆开来看，其核心正是构成科达-卡诺公式（Kármán-Carnot） 用于计算截面突变损失的分项！
Since the senior engineers over there have already completed the core calculations, there is naturally no need for us to repeat the work.
Pushing aside Secretary Liu, I locked onto a frequency from "Big Yellow's clone," who was acting as a server: "Seniors, how about we have an online chat? We can see the formulas in real time!"
"Hey! In our rush, we forgot about this great thing! Let's apply right away!"
After hanging up the phone, Jiang Xia began writing formulas in the text message interface.
Now, the important ones are the following formulas.
Diffusion loss: Δh conductance = ξd * (c1 - c2)^2 / (2g)
Where ξd is the diffusion loss coefficient, a crucial variable! Its magnitude mainly depends on two design parameters:
Cone angle θ (diffusion angle)
Area ratio A2/A1 (cross-sectional area after diameter change/cross-sectional area before diameter change)
Here's the key point! When the cone angle θ < 15°, a well-designed guide cone can significantly reduce ξd to a level of 0.1~0.2. Imagine if it were a sudden and abrupt increase, ξd could be as high as 1.0! Energy loss is reduced by 80-90%!
Contraction loss: Δh guide flow = ξc * c2^2 / (2g), where ξc: contraction loss coefficient. With optimized guide cone design (such as streamlined cone head), ξc can be as low as 0.05~0.1, while when suddenly contracted, ξc is about 0.5, and the optimization effect is equally significant!
而锥体的长度 L，则可以根据简单的几何关系确定：L = |D2 - D1| / (2 * tan(θ/2))（其中 D1、D2 分别是变径前后的管道直径）。
Perfect! The core parameters and design logic became clear instantly!
Hmm? You mean the author gave the protagonist a power-up?
Haha, this formula and some variations are right there in the textbooks! Seriously, it's in undergraduate programs! Back in the day, a top university even used this case study directly in their graduate entrance exam. I don't know if they were paying homage to their predecessors or just being lazy…
However, nowadays, professional courses mostly use CFD software for design, and even the nomograph for selecting the cone angle can be generated directly. Want the optimal θ? The answer is in a second.
Senior colleagues, the textbooks you wrote in the future will come to you in all sorts of creative ways!
Yes, what Jiangxia is doing now is simply giving back to these seniors the experience they've accumulated over a lifetime!
At this moment, Jiangxia is a conveyor of knowledge!
But he wasn't ashamed at all!