ICEGT (B-TECH Mechanical Engineering 5th)

UNIT – I Air Standard Cycles: Internal and external combustion engines; classification of I.C.

Engines, Cycles of operation in four stroke and two stroke I.C. Engines, Wankel Engines,

Assumptions made in air standard cycle; Otto cycle; diesel cycle, dual combustion cycle,

comparison of Otto, diesel and dual combustion cycles; sterling and Ericsson cycles; air

standard efficiency, specific work output, specific weight; work ratio; mean effective

pressure; deviation of actual engine cycle from ideal cycle. Problems.

UNIT – II Carburetion, fuel Injection and Ignition systems: Mixture requirements for various

operating conditions in S.I. Engines; elementary carburetor, Requirements of a diesel

injection system; types of inject systems; petrol injection, Requirements of ignition

system; types of ignition systems ignition timing; spark plugs. Problems.

UNIT – III Combustion in I.C. Engines : S.I. engines; Ignition limits; stages of combustion in S.I.

Engines; Ignition lag; velocity of flame propagation; detonation; effects of engine

variables on detonation; theories of detonation; octane rating of fuels; pre-ignition; S.I.

engine combustion chambers, Stages of combustion in C.I. Engines; delay period;

variables affecting delay period; knock in C.I. engines, Cetane rating; C.I. engine

combustion chambers.

UNIT – IV Lubrication and Cooling Systems: Functions of a lubricating system, Types of

lubrication system; mist, wet sump and dry sump systems; properties of lubricating oil;

SAE rating of lubricants, engine performance and lubrication, Necessity of engine

cooling; disadvantages of overcooling; cooling systems; air-cooling, water cooling;

radiators.

UNIT – V Engine Testing and Performance: Performance parameters: BHP, IHP, mechanical

efficiency, brake mean effective pressure and indicative mean effective pressure, torque,

volumetric efficiency; specific fuel consumption (BSFC, ISFC), thermal efficiency; heat

balance; Basic engine measurements; fuel and air consumption, brake power, indicated

power and friction power, heat lost to coolant and exhaust gases; performance curves.

Problems.

UNIT – VI Air pollution from I.C. Engine and Its remedies: Pollutants from S.I. and C.I. Engines,

Methods of emission control; alternative fuels for I.C. Engines; the current scenario on

the pollution front.

UNIT – VII Rotary Compressors: Root and vane blowers; Static and total head values; Centrifugal

compressors- Velocity diagrams, slip factor, ratio of compression, pressure coefficient,

pre-whirl; Axial flow compressor- Degree of reaction, polytropic efficincy, surging,

choking and stalling, performance characteristics, Problems.

UNIT – VIII Gas Turbines: Brayton cycle; Components of a gas turbine plant; open and closed types

of gas turbine plants; Optimum pressure ratio; Improvements of the basic gas turbine

cycle; multi stage compression with inter-cooling; multi stage expansion with reheating

between stages; exhaust gas heat exchanger, Applications of gas turbines. Problems.