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Pressure Added to a Flow Loop by a Pump?

  1. Mar 24, 2015 #1
    Hi there,

    I have set up a flow loop for a uni experiment that will teach other students about the bernoulli equation. The loop will use a few working section that will increase and decrease pressure due to diameter, velocity and height changes.

    I first set-up my loop with the pump at the end, pulling the water through the system so that i wouldn't have to worry about any discharge pressures. However i had to reverse this to get the pressure readings in the range of the pressure transducers.

    I have been calculating the pressures at a point using:
    p = density*gravity*height - 0.5*density*(velocity^2)
    where height is the distance below the water level to the transducer.
    I want to be able match the recorded pressures with some calculations, But now i have the pump at the start i am unsure how this adds to the pressures?
    I am able to calculate the flow rate, as the difference p2-p1 will cancel the constant out. If i use the pump curve to find the pressure head at this flow rate, is this the discharge pressure that i can add to the equation above to obtain the actual pressure at each point.

    Any help would be appreciated,

  2. jcsd
  3. Mar 24, 2015 #2
    Yes. The head is the outlet pressure minus the inlet pressure divided by ρg. Don't forget to include the turbulent frictional pressure drops, if these are significant (which they probably are).

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