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Radial suction fan

  1. Oct 29, 2015 #1
    Hi, I've been considering the design of a fan that sucks air radially and blows axially to resolve a technical problem of a machine. I've looked around for the equations governing the air particles and the angle of the radial blades (angle between a flat blade and a radial line) of the fans, but those equations are mostly developed for radial blowing fans and used to determine the pressure and velocity of air coming OUT radially. I would like to find a formula to determine what blade angle and RPM combination would cause air to be sucked radially and blown axially. Also, how to link constant RPM to the acceleration, velocity and displacement of a particle on the surface of a blade. Any help with this would be welcome... I tried to derive the equations based on free body diagrams, but I guess my physics are a bit rusty!!

    Thanks in advance for your time and help.


  2. jcsd
  3. Oct 30, 2015 #2


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    A radial inflow fan is a very difficult thing to design .

    An easier solution would be to use an axial fan and use ducts and inlet guide vanes to allow air to enter fan housing radially before passing through fan axially .
  4. Oct 30, 2015 #3
    Hi Nidum, thanks a lot for your reply. I had a similar thought and already conceptualized something along those lines (see image below). As you can see, I've attached the radial fan (on the right) to a cage with "hopefully" neutral air flow. So along the lines of what my original question was, I would like to understand the physics of an air particle resting on one of the blades of the "neutral" airflow cage, so I can make design it with either neutral or slight radial inflow. Do you know of any literature to help me here?

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  5. Dec 29, 2015 #4
    An Axial fan is basically a kind of compressor that can enhance the air pressure flowing through it. The range of axial flow fans is very wide and it may vary from a low or medium pressure fans to high pressure fans.
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