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    Assignment 4-1

    Uploaded by

    ashutosh
    This document contains 21 questions about hydraulic machines and turbines. It covers key concepts like gross head, net head, frictional loss head, turbine classifications, velocity triangles, expressions for work and efficiency of Pelton, Francis and Kaplan turbines, speed ratio, flow ratio, jet ratio, degree of reaction, draft tubes, specific speed, unit power, unit speed, unit discharge, turbine governing, and characteristics of turbines. Questions involve deriving expressions, solving problems related to hydraulic turbines, and determining parameters of turbines based on given specifications and operating conditions.

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    Download as PDF, TXT or read online from Scribd

    Assignment 4-1

    Uploaded by

    ashutosh
    38 views2 pages
    This document contains 21 questions about hydraulic machines and turbines. It covers key concepts like gross head, net head, frictional loss head, turbine classifications, velocity triangles, expressions for work and efficiency of Pelton, Francis and Kaplan turbines, speed ratio, flow ratio, jet ratio, degree of reaction, draft tubes, specific speed, unit power, unit speed, unit discharge, turbine governing, and characteristics of turbines. Questions involve deriving expressions, solving problems related to hydraulic turbines, and determining parameters of turbines based on given specifications and operating conditions.

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    This document contains 21 questions about hydraulic machines and turbines. It covers key concepts like gross head, net head, frictional loss head, turbine classifications, velocity triangles, expressions for work and efficiency of Pelton, Francis and Kaplan turbines, speed ratio, flow ratio, jet ratio, degree of reaction, draft tubes, specific speed, unit power, unit speed, unit discharge, turbine governing, and characteristics of turbines. Questions involve deriving expressions, solving problems related to hydraulic turbines, and determining parameters of turbines based on given specifications and operating conditions.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    38 views2 pages

    Assignment 4-1

    Uploaded by

    ashutosh
    This document contains 21 questions about hydraulic machines and turbines. It covers key concepts like gross head, net head, frictional loss head, turbine classifications, velocity triangles, expressions for work and efficiency of Pelton, Francis and Kaplan turbines, speed ratio, flow ratio, jet ratio, degree of reaction, draft tubes, specific speed, unit power, unit speed, unit discharge, turbine governing, and characteristics of turbines. Questions involve deriving expressions, solving problems related to hydraulic turbines, and determining parameters of turbines based on given specifications and operating conditions.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
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    Assignment 4

    1. Define the term: hydraulic machines, Turbines and Pump.


    2. What do you understand by
    a) Gross Head
    b) Net head
    c) Frictional loss head
    3. Explain the different types of the efficiency of a turbine.
    4. How will you classify the turbines?
    5. Draw the inlet and outlet velocity triangles for Pelton Wheel, Francis turbine, and
    Kaplan turbine and indicate the direction of various velocities.
    6. Obtain an expression for the work done per second by water on the runner of a Pelton
    wheel.
    7. Derive an expression for maximum efficiency of the Pelton wheel giving the
    relationship between the jet speed and bucket speed.
    8. Define the terms: speed ratio, flow ratio, and jet ratio.
    9. Define degree of reaction. Also derive an expression for the same.
    10. What is a draft tube? Why it is used in a reaction turbine? What is its function?
    11. Define the specific speed of a turbine? Derive an expression for the specific speed.
    12. Define the terms unit power, unit speed, and unit discharge with reference to a hydraulic
    turbine. Also derive expression for these terms.
    13. What is governing of a turbine? Describe with neat sketch the working of an oil pressure
    governor.
    14. Draw and discuss with neat sketch of main characteristics of a turbine.
    15. Obtain the expression for the force exerted by a jet of water on a moving vertical plate
    in the direction of the jet.
    16. A jet of water of diameter 50mm, having a velocity of 20m/s strikes a curved vane
    which is moving with a velocity of 10m/s in the direction of the jet. The jet leaves the
    vane at an angle of 60⁰ to the direction of motion of the vane at the outlet. Determine
    (i) force exerted by a jet on the vane in the direction of motion.
    (ii) work done per second by the jet.
    17. The three- jet Pelton turbine is required to generate 10,000kW under a net head of
    400m. The blade angle at outlet is 15⁰ and the reduction in the relative velocity while
    passing over the blade is 5%. If the overall efficiency of the wheel is 80%, coefficient
    of velocity is 0.98 and speed ratio is 0.46, then find (i) diameter of the jet (ii) total flow
    in m³/s (iii) force exerted by jet on the buckets.
    18. An outward flow reaction turbine has internal and external diameters of the runner as
    0.6m and 1.2m respectively. The guide blade angle is 15 and velocity of flow through
    the runner is constant and equal to 4m/s. If the speed of the turbine is 200 r.p.m., head
    on the turbine is 10m and discharge at outlet is radial, determine: (i) runner vane angles
    at inlet and outlet, (ii) work done by the water on the runner per second per unit weight
    of water striking per second. (iii) hydraulic efficiency.
    19. A Pelton wheel has a mean bucket speed of 10m/s with a jet of water flowing at the rate
    of 700 lt/s under a head of 30 meters. The bucket deflects the jet through an angle of
    160°. Calculate the power given by water to the runner and the hydraulic efficiency of
    the turbine. Assume co-efficient of velocity as 0.98.
    20. A turbine develops 9000 kW when running at 10 rpm. The head on the turbine is 30m.
    if the head on the turbine is reduced to 18 m, determine the speed and power developed
    by the turbine.
    21. A Francis turbine with an overall efficiency of 75% is required to produce 150 kW
    power. It is working under a head of 8 m. The peripheral velocity is 0.26 times absolute
    jet velocity and the radial velocity of flow is 0.96 time the absolute jet velocity. The
    wheel runs at 150 rpm and the hydraulic losses in the turbine are 22% of the available
    energy. Assuming the radial discharge, determine: i) the guide blade angle, ii) the wheel
    vane angle at inlet, iii) diameter of the wheel at inlet, and iv) width of the wheel at inlet.

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