JNTU B.Tech II FLUID MECHANICS AND HYDRAULIC MACHINERY Previous Question Paper (April/May - 2023 - R15)

What is Pascal’s law? Explain with one example.

If the pressure at appoint below the sea is 137.7 KN/m2 what is the pressure 30m below this point. Specific weight of ocean water is 10.06 KN/m2.

Explain any one application of momentum equation.

Write Darcy Weisbach equation.

Write about types of vanes.

Define and explain the significance of Utilization factor.

Differentiate between radial flow and tangential flow in turbines.

What is meant by Dynamic similarities?

What is specific speed of a pump? Give the equation for it.

Why the centrifugal pump impeller vanes backward curved?

Explain the phenomenon of surface tension on the top surface of liquids. What are the examples of surface tension?

A glass tube of internal diameter 4 mm is immersed in a liquid of specific gravity 12.2 and surface tension 0.55 N/m. The angle of contact with the glass is 120°. Calculate capillary rise or depression in the tube.

A clean tube of internal diameter 3mm is immersed in a liquid with a surface tension of 0.48N/m. The angle of contact of the liquid with the glass can be assumed to be 130°. The density of the liquid is 13600 Kg/m3. What would be the level of the?

Differentiate between: (i) Liquids and gases, (ii) Real fluid and ideal fluids, (iii) Specific weight and specific volume of a fluid.

A pipe of diameter 200 mm conveys a discharge of 2250 litres of water per minute and has a pressure of 15.70 kPa at a certain section. Find the total energy head with respect to a datum of 5 metres below the pipe.

A 300 mm diameter pipe conveying water branches into two pipes of diameter 250 mm and 200 mm and respectively. If the average velocities in the 300 mm and the 200 mm pipes be 2.5m/sec and 1 m/sec, calculate the velocity in the 250 mm pipe.

Oil with a free stream velocity of 3 m/s flows over a thin plate 1.25-m wide and 2 m long. Determine the boundary layer thickness and the shear stress at mid – length and calculate the total, double-sided resistance of the plate. Take p = 860 kg/m3 and ν = 10-3 m2/s.

Explain pipes in series and pipe in parallel with a neat sketch. Also write about Hydraulic Gradient line and Total energy line.

A jet of water of diameter 100 mm strikes a curved plate at its centre with a velocity of 15 m/s. The curved plate is moving with a velocity of 7 m/s in the direction of the jet. The jet is deflected through an angle of 150˚ assuming the plate smooth find: (i) Force exerted on the plate in the direction of the jet, (ii) power of the jet.

Explain elaborately about pumped storage plants.

Explain firm power and secondary power in detail.

What do you understand by hydroelectric power plant? What are its elements? Discuss them one by one with neat sketches.

Write about governing of turbines.

A reaction turbine works at 460 rpm under a head of 110 metres. Its diameter at inlet is 1150 mm and the flow area is 0.03 metre2. The angles made by the absolute velocity and relative velocity at inlet are respectively 18° and 50° with the tangential velocity. Determine (i) The volume flow rate (ii) The power developed (iii) The efficiency. Assume whirl at outlet to be zero.

A Kaplan turbine working under a head of 18 metres develops 18390 kW at an overall efficiency of 85%. The boss diameter is 0.3 times the runner diameter. If the velocity of flow is 9.05 metres per second, calculate the discharge and the diameters of the runner and the boss.

A turbine is to operate under a head of 30 metres at 250 rpm. The discharge is 10.5 m3/sec. If the efficiency is 85%, determine (i) Power generated, (ii) The specific speed of the turbine, (iii) Type of turbine, (iv) Performance under a head of 25 metres.

A Centrifugal pump delivers water against a net head of 17.5 meters and a design speed of 1000 r.p.m. The vanes are curved back to an angle of 30° with the periphery. The impeller diameter is 300 mm and out let width is 60 mm. Determine the discharge of the pump if manometric efficiency is 95%.

The following details refer to a centrifugal pump. Outer diameter= 30cm. Eye diameter = 15 cm. Blade angle at inlet = 30°. Blade angle at outlet = 25°; Speed =1450 rpm. The flow velocity remains constant. Determine the work done per kg. If the manometric efficiency is 82%, determine the working head. If width at outlet is 2 cm, determine the power ηo = 76%. (The whirl at inlet is zero).

A centrifugal pump is discharging water at the rate of 500 lt/min at 1200 RPM. The internal and external diameters and width of impellers are 12 cm and 24 cm and 16 mm and 8 mm respectively. The vanes are curved back 25° to the tangent at outlet. Find the increase in pressure, as water passes through the impeller.

What are characteristic curves of a centrifugal pump? What is the use of these curves?