WITH EFFECT FROM THE ACADEMIC YEAR 2012 - 2013

ME 304

HYDRAULIC MACHINERY AND SYSTEMS

Instruction                                             4              Periods per week

Duration of University Examination     3              Hours

University Examination                         75            Marks

Sessional                                                25            Marks

UNIT-I

Hydraulic Machines: Classification– Impulse momentum equation– Layout of hydraulic power plant – Working principle - Impact of jet on vanes – Force exerted by a jet striking (i) a fixed flat vertical vane held normal to the jet flow (ii) At the centre of a fixed symmetrical curved vane (iii) At one end of fixed symmetrical and unsymmetrical curved vanes (iv) Flat vertical vane moving in the direction of jet (v) A series of flat vertical moving vanes (vi) At the centre of a symmetrical moving curved vane (vii) A symmetrical curved vane moving in the same direction as that of jet at inlet (viii) At one end of an un-symmetrical moving curved vane (ix) Hinged plate

UNIT-II

Reciprocating Pumps: Classification, working principle-single and double acting pumps-discharge, work done and power required to drive the pumps-slip, % slip and negative slip- variation of pressure head in the

suction and delivery pipes due to acceleration of piston- variation of pressure head due to friction in the suction and delivery pipes -Indicator diagrams- Ideal and actual diagrams – Effect of piston acceleration and pipe friction on indicator diagram- Maximum speed at which the pump must run to avoid separation during suction and delivery strokes-Air vessels-Function of air vessels- Work saved by fitting air vessels to single and double acting pumps – Discharge of liquid into and out of air vessels-Performance characteristic curves.

Other types of pumps: Working principles and characteristics of gear pump and jet pump.

UNIT-III

Centrifugal pumps: Classification – Working principle – Comparison over reciprocating pumps – Velocity triangles – Manometric head – Work done per second – Head equivalent of work done – Manometric, mechanical and overall efficiencies – Pressure rise in the impeller – Minimum starting speed – Specific speed – Physical significance of specific speed – Model testing – Conditions of similarity of CF pumps – Priming – Performance characteristic curves – Troubles (operational difficulties), reasons and remedies in CF pumps – Cavitation – Effects of Cavitation – Precautions against Cavitation, working principle and characteristics of a self priming pump.

UNIT-IV

Hydraulic Turbines: Classification of impulse and reaction turbines – Construction and working of Pelton wheels, Francis turbine and Kaplan turbine – Velocity triangles – Work done (power developed) – Hydraulic, Mechanical and Overall efficiencies – Maximum efficiency – Comparison between Impulse and reaction turbines – Comparison between Francis and Kaplan turbines – Specific speed – Physical significance of specific speed – Unit quantities – Model testing of turbines – Conditions for similarity of turbines – Draft tubes – functions and types of draft tubes – Surge tanks – Functions and types of surge tanks – Performance characteristic curves.

UNIT-V

Industrial Hydraulics: Basic components of hydraulic circuits; Properties and types of hydraulic oils; Working principles of external Pumps - gear, lobe, vane, radial piston and axial piston; Construction details and actuating

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