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Pressure Loss owing to multiple nozzles

  1. Feb 19, 2013 #1
    The following is the advancement of what I discussed in the link https://www.physicsforums.com/showthread.php?p=4274966#post4274966

    Problem Statement
    To calculate Pump Discharge Pressure, Calculate the wattage for the pump

    Data :
    • Water @ 85 Degree C
    • Flow in for 24” pipe : 3010 m^3/hr
    • Flow in 8” pipe : 405 m^3/hr
    • Total length of pipe = 50ft
    • Nozzle Dia : 1"
    • Nozzle pressure : 100 psi
    • Nozzle Gallons per minute = 119
    • Number of Nozzles = 110 (placed equidistant along the length of the pipe)
    • Kinematic & Dynamic Viscosity of water can be found on : http://www.engineeringtoolbox.com/water-dynamic-kinematic-viscosity-d_596.html

    Is my approach (mentioned below) correct ?
    Pump Discharge Pressure = Pressure Loss owing to flow thru Horizontal Pipe + Nozzle Pressure* Number of Nozzles

    • Find Reynolds Number
    • Determine if its turbulent or laminar flow?
    • Find the relative roughness of the pipe
    • Find the friction factor, either from Moody’s chart or Colebrook equation
    • Then calculate pressure loss = (fρLV^2)/(D*2) in Pascal

    Now calculating Nozzle Pressure ,
    • Already given that per nozzle 100 psi. So total pressure loss owing to nozzles; is 100*110 and convert to Pascal units.

    Then add ;
    • pressure loss (calculated above) with the Pressure loss owing to those 110 Numbers of nozzles...
      and, use the above addition and multiply with the flow rate to attain the wattage ?

    Is this approach Correct ? Am I missing something ?
  2. jcsd
  3. Feb 20, 2013 #2
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