外文翻譯----冷卻系統(tǒng)技術的發(fā)展趨勢

1、<p><b>　　附錄1</b></p><p>　　冷卻系統(tǒng)技術的發(fā)展趨勢</p><p>　　大流量和高靜壓的新技術: 對旋式風機</p><p>　　Yoshihiko Aizawa</p><p>　　隨著世界核心技術(信息技術)的飛速發(fā)展，在許多電子設備當中譬如說服務器、通信器材等以CPU和PDD為

2、代表的固定設備不斷出了的微型化趨勢。這些設備在功能加的同時也伴隨著散熱的不斷增加, 這種情況預計在未來一段時間里將會一直持續(xù)下去。與此同時, 在微型化迅速發(fā)展的前提下，設備的零件會以更大的密度集中安裝一個基座上。結果,僅用一個風扇作為空氣動力源做散熱工作 ,很多情況下需要一種方案來改善散熱較多，阻力系數比較大的設備的散熱狀況。如果要具體地解決這個問題, 就需要一種具有更大風壓和流量的風扇。</p><p>　　以

3、前, 我們?yōu)橛脩魝兘鉀Q這種問題的方法通常是用一個大流量的風機和軸流風機聯(lián)合工作，或者是用一個高壓的風機配一臺離心風機再一個就是用兩臺離心風機同時工作。但是, 在同時要求需要很大的流量和很高的風壓的條件下，靠以前的兩臺風機聯(lián)合工作是不能滿足要求的，而且靠簡單的改進原有風機的流量和風壓；或者是修改葉輪葉片的設計方法和改變風機中電機的轉速等都不能夠達到這種要求。</p><p>　　以前, 當風機生產商們面對這種需要大

4、流量和高風壓的顧客時, 他們就需要改進軸流風機的結構來增加它的風壓或者是改進離心風機的結構來增加它的流量。因為軸流風機適合在一種阻力系數較低條件下用來冷卻一個設備，它可以較容易的獲得較大的風量，并且它可以適當地獲得一定的風壓。至于離心風機, 它不容易改進獲得較大的流量但是卻很容易獲得較高的靜態(tài)壓力, 并且它適合在阻力系數較高的設備中工作。兩種風機的結構和他們的特點詳細的列于下表 (1)。</p><p>　　對旋

5、軸流風機是一種有兩級葉輪并且葉輪轉向相反的風機。這是比較傳統(tǒng)的技術, 以前大多數被采取用于航空飛行器或者是直升機當中, 但是用來作為電子設備的冷卻風扇的例子卻很少。我認為主要原因是對旋軸流風機的噪聲問題一直以來都沒有被解決。而且有人認為對旋風機的輸送距離不如同類型的兩軸流風機。</p><p>　　對旋軸流風機有兩級葉輪，前后兩級葉輪的旋轉方向是相反的。</p><p>　　在工作過程中，

6、旋轉方向不同的第二級葉輪接受從第一級葉輪出來的氣流時，會將氣流的旋轉速度轉化為軸向的壓力（壓力補充）。由于氣流流經兩級葉輪系統(tǒng)的轉動時，兩葉輪中間沒有其他阻礙，大大減少了能量損失。</p><p>　　本文描述了新形勢下對高風壓、大流量風機的需求，并且簡單的改進以前的軸流風機或離心風機不能滿足這種需要。在這種情況下，提出了對旋風機的方案。</p><p>　　對旋風機能滿足顧客以前所不能達

7、到的高風壓、大流量的要求。文中把對旋風機和過去的研究結果做了對比。這里我要感謝大家的努力。我不能充分地說明對旋軸流風機工作的原理，因為我沒有仔細地對軸流風機的例子進行調查研究。我正在想繼續(xù)對各種現(xiàn)象進行考察和研究，為將來推出新型的產品而努力。最后我引用了一位高級工程師的研究內容，但我希望大家能體諒我的不足和欠缺。</p><p><b>　　參考文獻</b></p><p

8、>　　(1) 由JSME 編輯, 機械工程Handbook (1991) </p><p>　　(2) Sachio Harada, Fluid Machine SI Unit Version (1986), Asakura Shoten </p><p>　　(3) Yoshio Kodama 等, 對旋軸流風機特征的實驗性研究(動力學和噪聲), JSME 國際學報, 60-576

9、, B 1994-8 </p><p>　　(4) Yoshio Kodama 等, 關于對旋軸流風機的流體特性的實驗性研究, JSME 國際學報, 60-576, B 1994-8 </p><p>　　(5) Yoshio Kodama 等, 對旋軸流風機的噪聲研究 62-595, B 1996-3 </p><p><b>　　附錄2</b&g

10、t;</p><p>　　Cooling System Technology That Changes</p><p>　　The Conventional Trend</p><p>　　Technology for Large Air Volume and High Static Pressure : Counter Rotating Fan</p>

11、<p>　　Yoshihiko Aizawa</p><p>　　In electronic equipment such as servers and communication</p><p>　　devices, which are the kernel of IT (information technology) society, the miniaturizatio

12、n and improvement of the performance of the built-in parts represented by CPU and HDD are advancing at a marvelous speed. The heating value of these parts has also been increasing remarkably with the improvement of perfo

13、rmance, which is expected to continue in the future. At the same time, miniaturization is one of the preconditions in this equipment and the mounting densities of parts arranged in the device </p><p>　　highe

14、r in static pressure.</p><p>　　In the past, the solution offered to customers was either a</p><p>　　high air volume product with an axial flow fan or a high static pressure product with a centri

15、fugal fan, or both together.</p><p>　　However, in the case where the demand level of high air volume and high static pressure is extremely high as mentioned above and coexisting of both is also required, sim

16、ply improving the existing high air volume or high static pressure products by reviewing the blade design or improving the rotating speed is not sufficient.</p><p>　　In the past, fan makers, when faced with

17、the demand for</p><p>　　high air volume and high static pressure from customers, improved the performance of the axial flow fan when high air volume was needed or improved the centrifugal fan when high stati

18、c pressure was needed. The axial flow fan is suitable for cooling a device with comparatively low impedance since it can easily obtain high air volume though static pressure obtained is not so high. As for the centrifuga

19、l fan, it is not easy to improve air volume but easy to obtain high static pressure, and it is su</p><p>　　The counter rotating fan is a fan with the method of mutually</p><p>　　rotating two mov

20、ing blades in an opposite direction. This is a traditional technology, which has been adopted for use in aircrafts or helicopters, but examples of use as a cooling fan motor for electronic equipment are few. The main rea

21、son, I think, is that the weak point of the counter rotating fan’s loud noise could not be overcome until now. It has also been thought that it would not produce as much pressure as the axial flow fan in double stage in

22、series with enough distance(1).</p><p>　　The counter rotating axial flow fan is the kind of fan on which the driving blade with the shape that can receive the flow from the front driving blade smoothly is lo

23、cated in the back flow of the front driving blade to rotate it in an opposite direction of the front driving blade mutually. Consequently, the swirl element of the flow can be converted into pressure (pressure recovery).

24、 Also the collision loss, which is seen on the double stage in series fan, can be decreased. </p><p>　　This text described how the new requests for future fan</p><p>　　motors are high air volume

25、 and high static pressure, and also that the past measures of simply improving the performance</p><p>　　of axial flow fan or centrifugal fan cannot satisfy it. Next, an outline of the counter rotating fan wa

26、s presented. The counter rotating fan is a new solution for customers who need unprecedented volume of high air and high static pressure.</p><p>　　We have referred to the result of past research and the deve

27、lopment documents for counter rotating fans in this article. I would like to express our gratitude here. </p><p>　　We are not yet able to fully explain what is happening on compact counter rotating axial flo

28、w fan and one of the reasons is that we could not find an example of compact axial flow fan</p><p>　　(so-called box fan) identical to those we are dealing with as</p><p>　　a research object as f

29、ar as we had investigated. We intend to continue the search for effective factors to the phenomenon</p><p>　　investigation and the performance improvement, and to offer the market more epoch-making product i

30、n the future.</p><p>　　Finally, I have made an effort to quote the content of</p><p>　　the description of our senior engineers correctly when this</p><p>　　text was brought together

31、, but I humbly beg their pardon</p><p>　　for any parts that possibly lack accuracy.</p><p>　　References</p><p>　　(1) Edited by JSME, Mechanical Engineering Handbook (1991)</p>

32、<p>　　(2) Sachio Harada, Fluid Machine SI Unit Version (1986), Asakur a Shoten</p><p>　　(3) Yoshio Kodama et. al., Experimental study on the Characteristics of</p><p>　　Fluid Dynamics and

33、 Noise of a Counter-Rotating Fan(1st Report), JSME</p><p>　　International Journal, 60-576,B 1994-8</p><p>　　(4) Yoshio Kodama et. al., Experimental study on the Characteristics of Fluid</p>

34、;<p>　　Dynamics and Noise of a Counter-Rotating Fan(2nd Report), JSME International</p><p>　　Journal, 60-576,B 1994-8</p><p>　　(5) Yoshio Kodama et. al., Prediction of Turbulent Noise Gen

35、erated from</p><p>　　Counter-Rotating Axial Flow Fans, JSME International Journal,62-595,B</p><p><b>　　1996-3</b></p><p>　　Yoshihiko Aizawa</p><p>　　Joined