Head loss through freewheeling blower?
Head loss through freewheeling blower?
(OP)
Hello All,
Was wondering if anybody knows of a method to estimate head loss through a freewheeling centrifugal blower given the performance curve when the blower is running?
Seems to me there should be a relationship or rule of thumb to relate this to the powered performance curve.
Thanks for any guidance,
Arnermd
Was wondering if anybody knows of a method to estimate head loss through a freewheeling centrifugal blower given the performance curve when the blower is running?
Seems to me there should be a relationship or rule of thumb to relate this to the powered performance curve.
Thanks for any guidance,
Arnermd





RE: Head loss through freewheeling blower?
H2 = H1 * N2^2 / N1^2
N1 is blower running speed
N2 is freewheel speed
H2 should be something like = rho v^2/2/g
where v = freewheel tangential velocity
Let me know how that works out.
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RE: Head loss through freewheeling blower?
RE: Head loss through freewheeling blower?
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com
RE: Head loss through freewheeling blower?
Thanks for your thoughts.
Freewheeling means pretty much what BigInch said. In this particular case I am looking at a draft blower downstream of a micro turbine. The sole function of the draft fan is to make up for ducting losses, normally the micro turbine does not require a blower on the exit side but in this case we have a lot of duct work and associated pressure drop. I am trying to estimate what the backpressure will be if the blower does not turn on and to do this I need to know what it's pressure drop characteristic is.
BigInch: Interesting thought. Density won't change much, I am talking about inches of water for pressure rise. Only problem is I don't know what the freewheeling speed will be.
RE: Head loss through freewheeling blower?
Can't you just go spin one?
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RE: Head loss through freewheeling blower?
RE: Head loss through freewheeling blower?
When I said "given the performance curve when the blower is running" I literally meant a piece of paper with a curve on it, not that I had a blower up and running that i could measure performance.
If I had a system up and running I would shut the blower off and measure the gas flow through it with a pitot or high temp anemometer. Unfortunately I don't have that luxury right now.