JNTU B.Tech II FLUID MECHANICS AND HYDRAULIC MACHINES Previous Question Paper (May/June - 2019 - R16)

What are the applications of surface tension?

Explain atmospheric, gauge and vacuum pressure.

Describe the condition for Irrotational flow.

How do you find force acting on a pipe bend?

Define boundary layer with a neat sketch.

List Minor losses and explain briefly.

Define and explain hydraulic efficiency and mechanical efficiency.

How cavitations be avoided in reaction turbine?

What is NPSH? Explain.

What is an air vessel?

Derive the equation for capillarity depression when a small glass tube is inserted in mercury.

A piston of 7.95 cm diameter and 30 cm long works in a cylinder of 8.0 cm diameter. The annular space of the piston is filled with an oil of viscosity 2 poise. If an axial load of 10N is applied to the piston, calculate the speed of movement of the piston.

What is the importance of a manometer. Explain the types of manometers in brief.

A U-tube differential manometer is connected two pressure pipes A and B. Pipe A contains Carbon tetrachloride having a specific gravity 1.594 under a pressure of 1.772 N/cm² and pipe B contain oil of specific gravity 0.8 under pressure 11.72 N/cm². The pipe A lies 2.5 m above pipe B. Find the difference of pressure measured by mercury as a fluid filling U-tube.

Derive the equation of continuity in three dimension form.

Determine whether the following velocity components satisfy the continuity equation. i) u = cx, v = -cy ii) u = -cx/y , v = c log xy.

State the Bernoulli’s equation and discuss its significance.

A Water pipe changes in diameter from 400mm at section A to 800mm at section B which is 7 m above. The pressures at A and B are 100 KPa and 75 KPa respectively. The discharge is 400 litres/sec. Find the direction of flow.

Explain how a boundary layer separates from boundary. What are the conditions under which separation takes place?

Calculate the friction drag on a flat plate 15cm wide and 45cm long placed longitudinally in a stream of oil of relative density 0.925 and kinematic viscosity 0.9 stoke, flowing with a free stream velocity of 6.0 m/s. Also, find the thickness of the boundary layer and shear stress at the trailing edge.

What are hydraulic grade line and total energy line? How do you draw the same?

A venturimeter is used for measuring the flow of petrol in a pipe line inclined at 35⁰ to horizontal. The specific gravity of the petrol is 0.81 and throat area ratio is 4. If the difference in mercury levels in the gauges is 50mm, calculate the flow if the pipe diameter is 0.3m. Take coefficient of discharge as 0.975.

Prove that the force exerted by a jet of water on a fixed semi-circular plate in the direction of the jet when the jet strikes at the center of the semi-circular plate is two times the force exerted by the jet on an fixed vertical plate.

A Pelton wheel has a mean bucket speed of 35 m/s with a jet of water flowing at the rate of 1 m³/s under a head of 270 m. The buckets deflect the jet through an angle of 170⁰. Calculate the power delivered to the runner and the hydraulic efficiency of the turbine. Assume co-efficient of velocity as 0.98.

What is meant by governing of a turbine? When it is required? Explain any one method.

A Francis turbine working under a head of 5 m at a speed of 210 rpm develops 75 KW when the rate of flow of water is 1.8 m³/sec. If the head is increased to 16 m, determine the speed, discharge and power.

Define a centrifugal pump. Explain the working of a single stage centrifugal pump with neat sketches.

The diameter and width of a centrifugal pump impeller are 50 cm and 2.5 cm. The pump runs at 1200 rpm. The suction head is 6 m and the delivery head is 40 m. The frictional drop in suction is 2 m and in the delivery 8 m. The blade angle at out let is 30⁰. The manometric efficiency is 80% and the overall efficiency is 75%. Determine the power required to drive the pump. Also calculate the pressures at the suction and delivery side of the pump.

What is indicator diagram for a reciprocating pump? Explain slip and coefficient of discharge of a reciprocating pump.

A double acting reciprocating pump running at 40 r.p.m. is discharging 1.0 m³ of water per minute. The pump has a stroke of 400 mm. The diameter of the piston is 200 mm. The delivery and suction head are 20 m and 5 m respectively. Find the slip of the pump and power required to drive the pump.