Name: 為什麼風力渦輪機有三個葉片？ (Why Do Wind Turbines Have Three Blades?)
Uploaded: 2025-09-13T17:49:10.000Z
Duration: 4 min 4 s

程度副詞

It's possible to build a wind turbine with two blades, or five blades, or even one blade, but the vast majority of modern windmills have three blades, and there are three good reasons for that.

我們可以用兩個葉片、五個葉片甚至一個葉片來建造風力渦輪機，但絕大多數現代風車都有三個葉片，這有三個很好的理由。

The first reason for three blades comes from physics.

三個葉片的第一個原因來自物理學。

轉承詞

All else being equal, the more blades a windmill has, the more torque it can generate, but also the more drag it has, because each additional blade has to cut through the wind, and drag grows quickly the faster the windmill is spinning.

在其他條件相同的情況下，風車的葉片越多，所能產生的扭矩就越大，但阻力也越大，因為每增加一個葉片，風車就必須切割風，而風車旋轉得越快，阻力就增長得越快。

So in general, many bladed windmills work better at lower rotational speeds relative to wind speed.

是以，一般來說，許多葉片風車在相對風速較低的轉速下工作得更好。

On the other hand, a windmill with fewer blades generates less torque, but also experiences less drag, so fewer bladed windmills tend to work better at higher rotational speeds.

另一方面，葉片較少的風車產生的扭矩較小，但阻力也較小，是以葉片較少的風車在轉速較高時往往能更好地工作。

Here's a graph showing the efficiencies of turbines with different numbers of blades, where the x-axis shows how fast they're spinning relative to the wind, and the y-axis shows the efficiency of the turbine.

下面的圖表顯示了不同葉片數量的渦輪機的效率，X 軸表示葉片相對於風力的旋轉速度，Y 軸表示渦輪機的效率。

The efficiency for a five-blade turbine is highest at low speeds, while a one-blade turbine works better at high rotational speeds.

五葉渦輪機在低轉速時效率最高，而單葉渦輪機在高轉速時效率更高。

You can see that the highest possible efficiency of any turbine comes at intermediate speeds on this curve here, which corresponds to, you guessed it, three blades.

您可以看到，任何渦輪機的最高效率都出現在這條曲線的中間速度上，您猜對了，對應的是三個葉片。

But there's more to a turbine than efficiency – a super-high efficiency windmill is no use if it falls apart after just a little while.

但是，渦輪機的作用遠不止效率這麼簡單--如果效率超高的風車用不了多久就會散架，那它也就沒用了。

So the second reason why windmills have three blades comes from engineering.

是以，風車有三個葉片的第二個原因來自工程學。

The problem is that windmills have to be strong enough to withstand the many different bending and rotational and vibrational forces necessary for their operation.

問題是，風車必須足夠堅固，以承受運行時所需的多種不同的彎曲、旋轉和振動力。

For example, when the blades of a two-blade wind turbine are aligned with or opposite the pole, it can create an unbalanced twisting force under the wrong wind conditions.

例如，當雙葉風力渦輪機的葉片與電杆對齊或相對時，在錯誤的風力條件下會產生不平衡的扭曲力。

This can lead to large forces pushing the pole to bend forwards or backwards, or twist side to side.

這可能導致巨大的力推動電線杆向前或向後彎曲，或左右扭轉。

There are similar issues with other even numbers of blades, including for our purposes a single-blade rotor, since it only has a counterweight on the other side and nothing to balance the unequal wind forces.

其他偶數葉片也有類似的問題，就我們的目的而言，包括單葉轉子，因為它的另一側只有一個配重，沒有任何東西來平衡不相等的風力。

If the rotor has an odd number of blades, like three or five, the fact that blades don't come in pairs means that wind loads are more evenly distributed across the face of the rotor, and so the bending and twisting forces are greatly reduced.

如果轉子的葉片數量為奇數，如三個或五個，那麼葉片不成對出現就意味著風載荷在轉子表面的分佈更加均勻，是以彎曲力和扭轉力也會大大降低。

So in order to use two blades, the materials and engineering of the tower, hub, and blades need to be more robust, which costs more and negates many of the other cost benefits of using fewer blades.

是以，為了使用兩個葉片，塔架、輪轂和葉片的材料和工程設計需要更加堅固，這就需要花費更多的成本，並抵消了使用較少葉片的許多其他成本優勢。

Also, when comparing three and five blade designs with the two-blade design, the lower rotational speeds of turbines with more blades means that all the moving parts experience less wear over time.

此外，將三葉片和五葉片設計與雙葉片設計進行比較時，葉片越多的渦輪機轉速越低，這意味著所有運動部件的磨損時間越短。

So to minimize unwanted twisting forces from the wind, we want an odd number of blades, and more blades cause less wear and tear, but more blades cost more money.

是以，為了儘量減少風帶來的不必要的扭曲力，我們需要奇數個葉片，葉片越多，磨損越小，但葉片越多，成本越高。

If you took the blades from two five-blade turbines, you'd have enough to make three three-blade turbines, plus one left over.

如果從兩臺五葉渦輪機上取下葉片，就足以製造三臺三葉渦輪機，外加一臺剩餘葉片。

Taking all these engineering factors into account, three blades it is.

考慮到所有這些工程因素，三片刀片就是了。

The third reason for windmills to have three blades comes from human comfort.

風車有三個葉片的第三個原因來自於人類的舒適度。

If you want to build a windmill, you need people to be okay with you building a windmill, so how it looks and how it sounds matters.

如果你想建造一座風車，你就需要人們同意你建造一座風車，是以風車的外觀和聲音都很重要。

Three-blade rotors are generally considered more visually pleasing than a two-blade equivalent.

一般認為，三葉轉子比兩葉轉子更美觀。

One possible reason for this is that the space taken up by a three-blade rotor in the horizontal and vertical directions changes only slightly over time, whereas a two-blade rotor switches back and forth and back and forth between mostly horizontal and mostly vertical and generally looks more choppy.

其中一個可能的原因是，三葉轉子在水準和垂直方向上所佔的空間隨時間的推移變化很小，而兩葉轉子則在主要是水準方向和主要是垂直方向之間來回切換，通常看起來更不穩定。

Even at rest, people prefer the symmetry of three blades over two.

即使在靜止狀態下，人們也更喜歡三片葉片的對稱性，而不是兩片。

Three look pretty good, while two can look off-balance or awkward depending on how they're oriented relative to the tower.

三個看起來還不錯，而兩個可能看起來不平衡或笨拙，這取決於它們相對於塔的方向。

Wind turbines are also noisy, and basically all of the noise comes from the turbulence that forms as the blades cut through the air, so the least noisy windmills are the slowest.

風力渦輪機的噪音也很大，基本上所有噪音都來自葉片劃過空氣時形成的湍流，是以噪音最小的風車速度也最慢。

Looking again at the efficiency graph, we see that a three-blade rotor achieves the same or better level of efficiency at slower rotational speed than a two-blade rotor, which means for a given wind speed, three-blade windmills can run more quietly, though they are by no means silent.

再看一下效率圖，我們會發現三葉轉子在較低轉速下的效率與雙葉轉子相同或更好，這意味著在一定風速下，三葉風車可以更安靜地運行，儘管它們絕非靜音。

Obviously, we've glossed over some details, but essentially that's it – three good reasons that windmills have three blades.

顯然，我們忽略了一些細節，但基本上就是這樣--風車有三個葉片的三個很好的理由。

Physics says that three-blade rotors are most efficient, engineering says that for the same cost, three-blade rotors are less likely to break than two-blade ones, and human comfort says they're not noisy, headless stick figures.

物理學認為，三葉轉子效率最高；工程學認為，在成本相同的情況下，三葉轉子比兩葉轉子更不容易損壞；人體舒適度認為，三葉轉子不是嘈雜的無頭木棍。

The amount of electricity we can generate with wind power and other forms of clean energy is amazing – just look at this chart from the last 25 years.

我們利用風能和其他形式的清潔能源所能產生的電量是驚人的，看看過去 25 年的圖表就知道了。

So on September 21st, we're going to celebrate that progress and help push for even more in a series of events around the world – rallies, solar installations, parades, all sorts of stuff.

是以，9 月 21 日，我們將慶祝這一進展，並在世界各地舉辦一系列活動--集會、太陽能安裝、遊行等，幫助推動更多進展。

It's called Sunday – you know, the sun does power the wind.

這就是所謂的 "星期天"--要知道，太陽確實是風的動力。

And if you want to learn more about it, or attend an event, or even host your own, please check out sunday.earth.

如果你想了解更多資訊，或參加活動，甚至舉辦自己的活動，請訪問 sunday.earth。

Together we can make the sun rise on our clean energy future.

齊心協力，我們就能讓清潔能源的未來旭日東昇。