Axial blower for cylinder or pipe tunnel Centrifugal blower for ducting tunnel

I would like to build a small wind tunnel to test a miniaturized wing/airplane. I have two options, using axial blower (picture 1) or using centrifugal blower (picture 2). The first will be the wind source for "pipe" tunnel while the second one will be connected to a ducting tunnel. The size and the power (cfm) will be provided as per requirement.

Then my question: which one is better of the two? Or, is any other better alternative?

  • 1
    $\begingroup$ Purely anecdotally, all of the videos of aircraft wind tunnels I've seen use a circular fan like the first image, and not a blower like the second image. $\endgroup$
    – zymhan
    Commented Nov 6, 2019 at 17:45
  • $\begingroup$ What is that mean Purely anecdotally,... Sorry for my poor English. $\endgroup$ Commented Nov 7, 2019 at 1:48
  • $\begingroup$ No worries! It means I don't have an official source, I've just noticed it myself. $\endgroup$
    – zymhan
    Commented Nov 7, 2019 at 16:51
  • $\begingroup$ Thank you anyway. At least I have one reference. $\endgroup$ Commented Nov 8, 2019 at 16:14

1 Answer 1


You could make either one work, especially for a "straight through" tunnel. The key is to smooth out the turbulence after the fans to as straight and undisturbed a line as possible.

Smoke trails help check your wind stream before the model is put into place for testing, and remain valuable to see changes in the wind flow pattern as it passes over the forms.

There is an excellent article on the internet: howstuffworks wind tunnel, and a very good diagram showing post fan stages such as stators, vanes, diffusers, and settling chamber that help create a desirable flow.

For testing of lower subsonic designs, a straight through tunnel, such as the one the Wright brothers built, may be easiest to construct.

  • $\begingroup$ If we use smoke, what will be the density? $\endgroup$ Commented Nov 10, 2019 at 14:52
  • $\begingroup$ I will check the howstuffworks wind tunnel. $\endgroup$ Commented Nov 10, 2019 at 14:53
  • $\begingroup$ A small amount of smoke will not greatly affect density. Several lines between clear air are best. $\endgroup$ Commented Nov 10, 2019 at 14:54

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