Jawaharlal Nehru Technological University Hyderabad 2011-1st Year B.E Electrical and Electronics Engineering I B.TECH - MECHANICS AND HYDRAULIC MACHINERY (EEE) - Question Paper

II B.TECH - I SEMESTER exams - MAY, 2011
FLUID MECHANICS AND HYDRAULIC MACHINERY
(ELECTRICAL AND ELECTRONICS ENGINEERING)
Time: 3hours Max. Marks: 75
ans any 5 ques.
All ques. Carry Equal Marks
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1.a) A cylinder of 0.3m diameter rotates in annular sleeve of 0.31m internal diameter. Both the cylinders are 0.3m long. Determine the viscosity of the liquid which fills the space ranging from the cylinder if a torque of 0.98 N.m is needed to maintain an angular velocity of 2p rad/s.
b) With a neat sketch of 'u' tube connected to a pipe under pressure, discuss the procedure of writing manometric formula.(Assume the u tube manometer contain mercury on manometric liquid and open to atmosphere). Gauge 'A' attached at the bottom of a tank shown in figure reads 350KPa (abs). What is the height 'h' of water? What is the studying of gauge 'B'? [7+8]
Figure
2.a) describe steady, non steady, uniform and non uniform flow. The subsequent provided stream function responds a 2 dimensional steady state of flow ? = 4(x2 – y2). Check whether the flow is irrotational or not? If it is irrotational, then obtain out the corresponding velocity potential function.
b) define the nature of different forces normally included in the momentum formula. A vertical pipe carrying oil of sp.gravity 0.8 taken uniformly from 200mm diameter at the lower part to 100mm diameter at the upper part. The vertical distance ranging from the parts is one m. The pressure gauges installed at the lower and upper part learn six N/m2 and five N/m2 respectively when the discharge of oil is 30 litres/ seconds. compute the loss of head ranging from the 2 parts. Determine the direction of flow also. [7+8]
3.a) describe 'Hydraulic gradient line' and 'Total energy line'. The cross part of a pipe carrying a provided discharge is suddenly enlarged. What would be the ratio of the 2 diameters of the pipe if the magnitude of the loss of head at this change of part is identical irrespective of the direction of flow? presume CC = 0.64.
b) Determine the throat diameter of a venturimeter for installation in a 100mm diameter pipeline carrying oil of sp. Gravity 0.87. The maximum range of available oil – mercury differential gauges is 0.5 m of mercury deflection. obtain the maximum throat diameter which would show full gauge deflection when the rate of flow is 20 litres per second. presume Cd= 0.984. [7+8]

4.a) A jet having a velocity V strikes a single curved vane moving in the identical direction as the jet with velocity u, so that velocity of the jet relative to the vane is (v-u). The vane causes the jet to be reversed in direction. Show that the maximum efficiency is found when V = 3u and that this maximum efficiency is slightly less than 0.6.
b) A jet of water having a velocity of 15m/s strikes a curved vane which is moving with a velocity of five m/s. The vane is symmetrical and it is so shaped that jet is deflected through 1200. obtain the angle of the jet at inlet of the vane so that there is no shock. What is the absolute velocity of the jet at outlet in magnitude and direction? [7+8]
5.a) describe Gross head and Net head as applied to hydraulic turbine. How effective head of reaction turbine differs from impulse turbine.
b) How hydro power plants are classified on functional basis and on the basis of head under which they operate? [8+7]
6.a) With neat sketch discuss draft tube. Why draft tube is used in reaction turbine? discuss how the net head on the reaction turbine is increased with the use of draft tube.
b) obtain out the hydraulic power developed by the pelton wheel which is moving with a velocity of 20m/s. The net head available on the nozzle is 50m. Take subsequent data Cv = 0.98, Angle of deflection is 1650 and discharge Q = 30 liters/second. [7+8]
7.a) discuss unit speed, unit discharge & unit power of hydraulic turbine. Why they are described for the turbine?
b) A pelton wheel develops 5520 kW break power when running at 180 RPM and head available is 250m and overall efficiency is 80%. The speed ratio is 0.46. obtain the speed, discharge and power developed when available head is decreased to 200m. [7+8]
8.a) Prove that minimum speed needed for the centrifugal pump to begin is provided by
()222221120manoVwDNDD?p=-
b) The inner and outer diameter of the impeller of a centrifugal pump are 250mm and 500mm. The velocity of flow through the impeller is constant and 5m/s. Taking outlet vane angle as 450; obtain inlet vane angle, absolute velocity of water at outlet and power available at the pump when it is running at 1200 rpm and discharging at the rate of 0.2 m3/s. [7+8]

Earning:   Approval pending.