JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II Year MECHANICS OF FLUIDS AND HYDRAULIC MACHINES Previous Question Paper (December - 2018 - R15)

Define Viscosity and explain Newton’s law of Viscosity.

Derive the expression for Capillary rise or fall with neat diagram.

Distinguish between surface and body forces.

Mention different types of Classification of fluid flows.

What is boundary layer thickness?

Discuss the importance of Reynold’s experiment.

Explain the fundamental differences between turbine and pump.

Draw the inlet and outlet triangle diagrams for Pelton wheel.

Define manometric and mechanical efficiency of a centrifugal pump.

Explain what is slip?

A shaft with a diameter of 0.5 m rotates at 200 rpm inside a sleeve with a diameter 0.502 m with uniform clearance. If the power required to rotate the shaft is 5.0 kW, find the viscosity of oil in the clearance, length of sleeve is 250 mm.

Derive the relation between pressure P inside a free jet of liquid and surface tension.

Find the pressure difference between points A and B as shown in figure.

Castor Oil of viscosity 0.9 N-S/m2 fills the space between two concentric cylinders of 15 cm and 15.2 cm and each 25 cm height. Find the torque required to rotate the inner cylinder at 20 rpm if the outer cylinder is stationary.

Derive the continuity equation in 3 dimensional flow for steady flow condition in Cartesian coordinate system and list out various assumptions.

Differentiate between rotational and irrotational flow? What is Laplace equation? Explain.

Explain the significance and importance of Momentum principle used in Fluid mechanics. Discuss the application of Momentum principle in case of pipe bend with neat sketch.

Find the equation of stream line passing through point (2, 4) for V= 3xi -3yj.

Determine whether the following velocity components satisfy the continuity equation u= 2x2 +zy, v= -2xy+3y3 +3xy, w= -3/2 z2 -2xy -6yz.

A 1.8 m wide and 5.0 m long plate moves through a stationary air of density 1.22 kg/m3 and viscosity 1.8 × 10-4 poise at a velocity of 1.75 m/s parallel to its length. Determine the drag force on one side of the plate by assuming i) laminar flow ii) turbulent flow condition.

Discuss the boundary layer separation and steps to prevent the same.

The inlet and throat diameters of a Venturimeter in horizontal position are 30 cm and 10 cm respectively and the flowing fluid is water. The intensity of pressure at the inlet is 0.85 N/cm2 and vacuum pressure is at the throat is 37 cm of mercury. Calculate the flow rate assuming 4% of loss of the head between throat and inlet, calculate Cd also?

Explain the following with neat sketches i) Orifice meter ii) Flow nozzle meter.

A Pelton wheel is to be designed for the following specifications: Power: 10,000 KW, Head 400 m, Speed 800 rpm, Overall efficiency: 85%, Jet Diameter: 1/6th of wheel diameter. Determine: Wheel Diameter, Diameter of Jet, Number of Jets required. Take Cv =0.985, Speed Ratio= 0.45

Explain the characteristic curves of turbine.

A hydraulic turbine is to develop 850 KW when running at 100 rpm under a head of 10 m. Work out the maximum flow rate and specific speed for the turbine if the overall efficiency at the best operating point is 92%. In order to predict its performance a 1:10 scale model is tested under a head of 6 m. What would be speed, power output and water consumption of the model if it runs under the conditions similar to prototype.

Derive the expression for rise in pressure due to water hammer considering for both rigid and elastic pipes. Clearly write the assumptions.

Draw the neat diagram of centrifugal pump and explain components of centrifugal pump.

Explain about NPSH.

Explain the indicator diagrams in reciprocating pumps.

A pump operates at a maximum efficiency of 82% and delivers 2.25 m3/s under a head of 18 m while running at 4000 rpm speed. Compute the specific speed of the pump. Also determine the discharge, head, and power input to pump at a shaft speed of 2500 rpm. Cite the assumptions made if any.