Internal Combustion Engines Faculty - Er. Ashis Saxena

Index Unit 1 Introduction to I.C Engines Fuels Unit 2 SI Engines Unit 3 CI Engines Unit 4 Engine Cooling Lubrication Supercharging Testing and Performance Unit 5 Compressors

Unit - 1 Chapter - 1 Introduction to I.C Engines

Engine  An Engine is a device transforming one form of energy into other.

Heat Engine  A Heat Engine is a device which transforms chemical energy of a fuel into thermal energy and this thermal energy is converted to mechanical work.

IC Engine  The Internal Combustion Engine (also known as IC Engine) is an engine in which the combustion of fuel and an oxidizer (typically air) occurs inside a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure, which are permitted to expand inside that confined chamber. Thrust produced by this expanding gas drives the engine creating useful work.

IC Engine Terminology Piston Cylinder Assembly: It is the assembly for manipulating the working fluid. The assembly is characterized by a piston moving inside the confined cylinder. Inlet Valve: The valve through which air fuel mixture (in case of SI engine) or air (in case of CI engine) is introduced inside the cylinder. Exhaust Valve: The valve through which the products of combustion leave the cylinder. Crank Mechanism: Mechanism to convert reciprocating piston motion to rotary motion. Bore: Diameter of Cylinder. Top Dead Center (TDC): Position of Piston where Cylinder Volume is minimum. Bottom Dead Center (BDC): Position of Piston where Cylinder Volume is maximum. Stroke: It is the maximum distance that the piston moves in one direction. It is the distance between TDC to BDC. Clearance Volume (Vc): Minimum Cylinder volume when Piston is at TDC. Displacement Volume (Vd): Volume swept out by the Piston as it moves from TDC to BDC. Compression Ratio (rv): Ratio of volume at TDC and volume at BDC.

Engine Classification

Engine Design 1. On the basis of Engine Design  Reciprocating (piston) 4 stroke cycle 2 stroke cycle (not currently used in automotive applications)  Rotary

Working Cycle 2. On the basis of Working Cycle  Engines working on Otto cycle (SI Engines)  Engines working on Diesel cycle (CI Engines)

Fuel 3. On the basis of Fuel  Gasoline (Petrol Engines)  Compressed Natural Gas (CNG) Engines  Diesel (Light Diesel oil (LDO) or High Speed Diesel oil (HSD)) Engines  Liquefied Petroleum Gas (LPG) Engines  Liquefied Natural Gas (LNG) Engines  Hydrogen Engines  Dual Engines  Multi Fuel Engines

Cylinder Arrangement 4. On the basis of Cylinder Arrangement  Inline 3/4/5/6 cylinder configurations  V-type 6/8/10 cylinder configurations  Radial  Horizontally Opposed 4/6 cylinder configurations

Camshaft Location and Number 5. On the basis of Camshaft Location and Number  Overhead Cam (OHC): cam located in cylinder head SOHC: one cam for both intake and exhaust valves DOHC: separate intake and exhaust cams  Pushrod: cam located in engine block

Ignition Systems 6. On the basis of Ignition Systems  Method for igniting air/fuel mixture Spark Ignition (SI)  Gasoline  LNG  CNG  Alternative fuels Compression Ignition (CI)  Diesel

Combustion Chamber Designs 7. On the basis of Combustion Chamber Designs  Wedge: Intake and exhaust valves set in a plane Spark plug located above or below valve plane  Hemispherical (hemi): Valves set in two planes Spark plug located between valves More efficient Higher output

Application 8. On the basis of Application 1. Automotive: (i) Car (ii) Truck/Bus (iii) Off-highway 2. Locomotive 3. Light Aircraft 4.Marine: 5. Power Generation: (i) Portable (Domestic) (ii) Fixed (Peak Power) 6. Agricultural: (i) Tractors (ii) Pump sets 7. Earthmoving: (i) Dumpers (ii) Tippers (iii) Mining Equipment 8.Home Use: (i) Lawnmowers (ii) Snow blowers (iii) Tools 9.Others

Difference between EC & IC Engines

Largest internal combustion engine Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel, built in Finland, used in container ships 14 cylinder version: weight 2300 tons; length 89 feet; height 44 feet; max. power 108, rpm; max. torque 5,608,312 ft 102 RPM Power/weight = hp/lb Also one of the most efficient IC engines: 51%

Most powerful internal combustion engine Wartsila-Sulzer RTA96-C is the largest IC engine, but the Space Shuttle Solid Rocket Boosters are the most powerful (≈ 42 million horsepower (32 hp/lb); not shaft power but kinetic energy of exhaust stream) Most powerful shaft-power engine: Siemens SGT5-8000H stationary gas turbine (340 MW = 456,000 HP) (0.52 hp/lb) used for electrical power generation

Smallest internal combustion engine Cox Tee Dee 010 Application: model airplanes Weight: 0.49 oz. Displacement: in3 (0.163 cm3) RPM: 30,000 Power: 5 watts Ignition: Glow plug Typical fuel: castor oil ( %), nitromethane (0 - 50%), balance methanol Good power/weight (0.22 hp/lb) but poor performance –Low efficiency (< 5%) –Emissions & noise unacceptable for many applications

Air Standard Cycles - Introduction

Ideal or Air Standard Cycle

Air Standard Cycle - Assumptions

Otto Cycle

Ideal Otto Cycle

Ideal Otto Cycle - Working

Otto Cycle - Working

Actual Otto Cycle

Actual Otto Cycle - Working

Engine Working on Otto Cycle

Ideal Otto Cycle - Analysis

Diesel Cycle

Difference between Diesel Engine & Petrol Engine

Diesel Cycle

Why Otto cycle is Constant Volume cycle and Diesel cycle is Constant Pressure cycle?

Diesel Engine

Difference between 2 stroke and 4 stroke engines

Difference between SI & CI engines

Difference between SI & CI engines contd...

Why Diesel engines are more fuel efficient?

Stirling Cycle

Stirling Engine

Displacer-type Stirling Engine

Stirling Engine

Displacer-type Stirling Engine

Two-piston Stirling Engine

Why Aren't Stirling Engines More Common?

Other Applications

Solar Stirling engine

Large Solar Stirling engine

Ericsson Cycle

Ericsson Cycle - Detailed

Ericsson Engine A cold gaseous working fluid, such as atmospheric air (shown in blue), enters the cylinder via a non-return supply valve at the top-right. The air is compressed by the piston (orange) as the piston moves upward. The compressed air is stored in the pneumatic tank (at left). A two-way supply valve (below left) moves downward to allow pressurized air to pass through the regenerator where it is preheated. The air then enters the space below the piston, which is an externally- heated expansion-chamber. The air expands and does work on the piston as it moves upward. After the expansion stroke, the two- way valve moves upward, thus closing off the tank and opening the exhaust port. As the piston moves back downward in the exhaust stroke, hot air is pushed back through the regenerator, which reclaims most of the heat, before passing out the exhaust port (left) as cool air.

Valve Timing Diagram

Valve Timing Diagram explained

Valve Timing Diagram

Valve Timing Diagram - Video

Rotary engines

Rise and fall of Rotary engines

NSU's rotary engines

GM's effort, Citroen, Mercedes and Nissan

Mazda - the only survivor

RX-8 and RENESIS

Principle of a Rotary engine

Parts of a Rotary engine

Working of a Rotary engine

Rotary Engine Advantages/Disadvantages