Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Static pressure and airflow at reduced fan speeds

  1. Apr 10, 2012 #1
    This is probably a stupid question but I've been going around in circles for a while now and have gotten myself completely confused.

    I have a fan and a pump, with performance charts (static pressure vs. air flow) for both. I need to try and determine flow rates for each device when run at reduced speeds.

    The fan/pump will be pulling a gas flow through a small tube, and exhausting to atmosphere. I know that's not the right way to use a fan, but that's what I'm stuck with right now. I can measure the pressure at the fan/pump inlet while running at different voltages.

    Searching around the internet, I found that air flow is linearly proportional to fan speed and static pressure is proportional to fan speed squared.

    So I'm guessing that if I'm at half the fan speed I should be at a quarter (.52) of the static pressure. I can measure the pressure, multiply by 4 and look it up on the chart. Then take the corresponding air flow and knock it in half to get the actual flow rate.

    That's a complete guess. If anyone can steer me in the right direction, I would appreciate it because I'm really stuck here. Thanks for your help.

  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted