Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    The bent cone nozzle carries a water flow of 25kg/s. At point 2 the flow discharges into the atmosphere, and at point 1 the nozzle is bolted to a rigid pipe. Assume the flow to be frictionless. The pipe diameter at point 1 is 100mm and 70mm at point 2. Calculate the magnitude and the direction of total force exerted by the water on the nozzle, if the gauge pressure at point 1 is p1 = 65kPa.

    The angle is 60 degrees.
    Offline

    12
    ReputationRep:
    (Original post by Lawalk97)
    The bent cone nozzle carries a water flow of 25kg/s. At point 2 the flow discharges into the atmosphere, and at point 1 the nozzle is bolted to a rigid pipe. Assume the flow to be frictionless. The pipe diameter at point 1 is 100mm and 70mm at point 2. Calculate the magnitude and the direction of total force exerted by the water on the nozzle, if the gauge pressure at point 1 is p1 = 65kPa.

    The angle is 60 degrees.
    I didn't quite get the question. My assumptions:
    1) The pipe and nozzle junction is horizontal and nozzle outlet is inclined at 60 degrees below horizontal.
    2) Density of water is constant i.e. 1000 kg/m^3, throughout the operation.
    3) As change in height is not indicated, change is potential energy is assumed to be negligible.
    4) Isothermal condition is assumed.

    If that's the case then, velocity of water at inlet is given by (25kg/s / (density of water X area of cross section at inlet) = 3.183098862 m/s.
    By using continuity equation (A1 v1 = A2 v2) we get velocity of water at outlet = 6.496120126 m/s.
    By using Bernoulli's equation we have pressure at outlet = 48966.27 Pa

    Pressure Force on the inlet = 65,000 X area of inlet = 510.51 N horizontally towards right
    Pressure Force on the outlet = 48966.27 X area of outlet = 188.44 N at angle 60 degrees above horizontal towards left.

    For the force, Resolve these forces horizontally and vertically. which should give you total force of 447.13 N at an angle of 40.98 degrees above horizontal.

    Hope this helps.
    If it does not then change the assumptions as required and perform calculations in similar manner.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by tangotangopapa2)
    I didn't quite get the question. My assumptions:
    1) The pipe and nozzle junction is horizontal and nozzle outlet is inclined at 60 degrees below horizontal.
    2) Density of water is constant i.e. 1000 kg/m^3, throughout the operation.
    3) As change in height is not indicated, change is potential energy is assumed to be negligible.
    4) Isothermal condition is assumed.

    If that's the case then, velocity of water at inlet is given by (25kg/s / (density of water X area of cross section at inlet) = 3.183098862 m/s.
    By using continuity equation (A1 v1 = A2 v2) we get velocity of water at outlet = 6.496120126 m/s.
    By using Bernoulli's equation we have pressure at outlet = 48966.27 Pa

    Pressure Force on the inlet = 65,000 X area of inlet = 510.51 N horizontally towards right
    Pressure Force on the outlet = 48966.27 X area of outlet = 188.44 N at angle 60 degrees above horizontal towards left.

    For the force, Resolve these forces horizontally and vertically. which should give you total force of 447.13 N at an angle of 40.98 degrees above horizontal.

    Hope this helps.
    If it does not then change the assumptions as required and perform calculations in similar manner.
    Thanks for the reply!
    The question is written exactly how it is in the exam paper. I found it hard to understand as well. From what you have written it has helped greatly. Thanks
    Offline

    12
    ReputationRep:
    (Original post by Lawalk97)
    Thanks for the reply!
    The question is written exactly how it is in the exam paper. I found it hard to understand as well. From what you have written it has helped greatly. Thanks
    No problem
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Has a teacher ever helped you cheat?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Write a reply...
    Reply
    Hide
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.