Classification of I.C Engines Components of I.C Engines Basic nomenclature of I.C Engines Internal Combustion ENGINES !
Application Basic Engine Design Operating Cycle Working Cycle Valve/Port Design and Location Fuel Mixture Preparation Ignition Stratification of Charge Combustion Chamber Design Method of Load Control Cooling BASES FOR CLASSIFICATION OF I.C ENGINES
Automotive :- Car, bus, truck, off highway Locomotive Light Aircraft Marine :- Outboard, Inboard, Ship Power Generation :- Portable, Fixed Agricultural :- Tractors, Pump sets Earth Moving :- Dumpers, Tippers, Mining Home :- Lawn movers, Snow blowers, Tools Based on Application
Automotive Diesel Engine
Large Two-stroke Marine Engine
1. Reciprocating :- (a) Single Cylinder (b) Multi-cylinder ( I) In-line (ii ) V Engine (iii) Radial (iv) Opposed Cylinder ( v) Opposed Piston 2. Rotary :- ( a) Single Rotor (b) Multi-rotor Based on the Engine Design
Types of Reciprocating Engines
V Engine
Wankel Rotary Piston Engine
Types of Rotary Engines
Otto (For Conventional SI Engine) Atkinson ( For Complete Expansion SI Engine ) Miller ( For Early or Late Inlet Valve Closing type SI Engine) Diesel ( For the Ideal Diesel Engine) Dual ( For the Actual Diesel Engine) Based on Operating Cycle
1. Four Stroke Cycle :- ( a) Naturally Aspirated ( b)Supercharged/Turbocharged 2 . Two Stroke Cycle :- ( a) Crankcase Scavenged ( b) Uniflow Scavenged ( i ) Inlet valve/Exhaust Port (ii) Inlet Port/Exhaust Valve (iii) Inlet and Exhaust Valve May be Naturally Aspirated Turbocharged Based on Working Cycle (Strokes)
Four s troke Two stroke SI & CI Engines
1 . Poppet Valve 2. Rotary Valve 3. Reed Valve 4. Piston Controlled Porting 1 . The T-head 2. The L-head 3. The F-head 4. The I-head ( i ) Over head Valve (OHV) ( ii) Over head Cam (OHC) Based on the Valve/Port Design Based on the Valve Location
Poppet Valve & Rotary Valve
Valve Locations
1.Conventional : (a) Crude oil derived: ( i ) Petrol ( ii) Diesel ( b) Other sources: ( i ) Coal ( ii) Wood (includes bio-mass) ( iii)Tar Sands ( iv)Shale 2 . Alternate: (a) Petroleum derived ( i ) CNG (ii) LPG ( b) Bio-mass Derived ( i ) Alcohols (methyl and ethyl) ( ii) Vegetable oils ( iii) Producer gas and biogas ( iv) Hydrogen 3. Blending 4 . Dual fueling Based on type of Fuel Used
1 . Carburetion 2. Fuel Injection ( i ) Diesel (ii) Gasoline (a) Manifold (b) Port (c) Cylinder Based on Mixture Preparation
1 . Spark Ignition (a) Conventional ( i ) Battery (ii)Magneto (b) Other methods 2 . Compression Ignition Based on type of Ignition
1. Homogeneous Charge: ( Also Pre-mixed charge) Admission of air-fuel mixture at near atmospheric pressure 2 . Stratified Charge: ( i ) With carburetion ( ii) With fuel injection Admission of mixture at pressure above atmospheric Based on Charge Stratification
1 . Open Chamber: ( i ) Disc type (ii) Wedge ( iii) Hemispherical ( iv) Bowl-in-piston ( v) Other design 2 . Divided Chamber: ( For CI): ( i ) Swirl chamber ( ii) Pre-chamber (For SI ): ( i ) CVCC ( ii) Other designs Based on Combustion Chamber Designs
Combustion Chamber Designs
1. Throttling : ( To keep mixture strength constant ) Also called Charge Control Used in the Carbureted S.I. Engine 2. Fuel Control: ( To vary the mixture strength according to load ) Used in the C.I. Engine 3. Combination Used in the Fuel-injected S.I. Engine. Based on Method of Load Control
1. Direct Air-cooling 2. Indirect Air-cooling (Liquid Cooling) 3. Low Heat Rejection (Semi-adiabatic) engine. Based on Methods of Cooling
Cylinder Cylinder head Piston &piston rings and piston pin Connecting rod Combustion Chamber Crank and crankshaft Crank case Inlet & Exhaust Valves Valve spring Components of IC engine
Inlet manifold and exhaust manifold Cam shaft Cam and cam follower Water jacket Flywheel Governor Carburettor Spark Plug Fuel pump Fuel nozzle
Cylinder Bore (d) Piston area (A) Stroke (L) Stroke to Bore ratio (L/d) Dead Centre Top Dead Centre(TDC) Bottom Dead Centre(BDC) Displacement of Swept Volume (Vs) Cubic Capacity or Engine Capacity Clearance Volume ( Vc ) Compression Ratio (r) Nomenclature of IC Engines
Top Dead Center (TDC): Position of the piston when it stops at the furthest point away from the crankshaft. Top because this position is at the top of the engines (not always), and dead because the piston stops as this point. Because in some engines TDC is not at the top of the engines(e.g: horizontally opposed engines, radial engines,etc,.) Some sources call this position Head End Dead Center (HEDC). Some source call this point TOP Center (TC). When the piston is at TDC, the volume in the cylinder is a minimum called the clearance volume.
Bottom Dead Center (BDC ): Position of the piston when it stops at the point closest to the crankshaft. Some sources call this Crank End Dead Center (CEDC) because it is not always at the bottom of the engine.Some source call this point Bottom Center (BC). Stroke : Distance traveled by the piston from one extreme position to the other : TDC to BDC or BDC to TDC. Bore : It is defined as c ylinder diameter or piston face diameter; piston face diameter is same as cylinder diameter( minus small clearance). Swept volume/Displacement volume : Volume displaced by the piston as it travels through one stroke. Swept volume is defined as stroke times bore. Displacement can be given for one cylinder or entire engine (one cylinder times number of cylinders).
Piston area: The area of a circle of diameter equal to the cylinder bore is called the piston area. Stroke to bore ratio: Ratio of stroke to cylinder bore is important parameter in classifying the size of the engine. If d<L, it is called under-square engine. If d=L, it is called square engine. If d>L, it is called over-square engine(It can operate at higher speeds).
Clearance volume : It is the minimum volume of the cylinder available for the charge (air or air fuel mixture) when the piston reaches at its outermost point (top dead center or outer dead center) during compression stroke of the cycle. Minimum volume of combustion chamber with piston at TDC. Compression ratio : The ratio of total volume to clearance volume of the cylinder is the compression ratio of the engine. Typically compression ratio for SI engines varies form 8 to 12 and for CI engines it varies from 12 to 24