Internal Combustion Engines OR IC Engines

Introduction 4 lectures 30:14 Introduction to IC engines & their classifications. Internal Combustion Engines are heat engines in which combustion takes place inside of engine cylinder with an oxidizer (generally air). Internal combustion heat engines work on the principle of the ideal gas law: pV=nRT. (Ideal gas law) An internal combustion engine has a chamber, which has fuel added to it which ignites in order to raise the temperature of the gas.When heat is added to the system, it forces gas inside to expand, this causes the piston to rise, and in case of a gas turbine, the hot air is forced into the turbine chamber...By attaching the piston or turbine to a camshaft, the engine is able to convert a portion of the energy input to the system into useful work.To compress the piston in an intermittent combustion engine, the engine exhausts the gas. A heat sink is then used to keep the system running at a consistent temperature. A gas turbine, which uses continuous combustion, simply exhausts its gas continuously rather than in a cycle. The classification of IC engines is covered in this lecture along with basic introduction. Main components of I.C.engine. What are the components which makes an IC engine.... The answer is hundreds of. Out of these many components, we are going to have a discussion regarding cylinder,cylinder head,piston,piston rings,connecting rod,crankshaft & other major components.A brief description about each of these major components are enlisted below ; Cylinder - Cylinder is the main body of IC engine. Cylinder is a part in which the intake of fuel, compression of fuel and burning of fuel take place. The main function of cylinder is to guide the piston. Cylinder head - One end of the cylinder is closed by means of cylinder head. This consists of inlet valve for admitting air fuel mixture and exhaust valve for removing the products of combustion.The inlet valve, exhaust valve, spark plug, injector etc. are bolted on the cylinder head. The main function of cylinder head is to seal the cylinder block and not to permit entry and exit of gases on cover head valve engine.Generally made up of aluminium alloys. Piston - It transmits the energy to crankshaft through connecting rod. Piston rings - These are used to maintain a pressure tight seal between the piston and cylinder walls and also it transfer the heat from the piston head to cylinder walls.These rings are fitted in grooves which have been cut in the piston. They are split at one end so they can expand or slipped over the end of piston.Generally made of highly elastic material or fine grain cast iron. Connecting Rods - One end of the connecting rod is connected to piston through piston pin while the other is connected to crank through crank pin.It transmits the reciprocatory motion of piston to rotary crank."Big end of the connecting rod is connected to the crankshaft and the small end is connected to the piston by using piston pin".Generally made of low carbon steels. Crank - A lever between connecting rod and crank shaft. Crank Shaft - The function of crank shaft is to transform reciprocating motion in to a rotary motion.The crankshaft of an internal combustion engine receives the efforts or thrust supplied by piston to the connecting rod and converts the reciprocating motion of piston into rotary motion of crankshaft.The crankshaft mounts in bearing so it can rotate freely."The shape and size of crankshaft depends on the number and arrangement of cylinders." Valve timing diagrams. A valve timing diagram is a graphical representation of the opening and closing of the inlet (Intake) and outlet (Exhaust) valve of the engine, The opening and closing of the valves of the engine depend upon the movement of piston from TDC (Top Dead Center) to BDC (Bottom Dead Center). Encapsulating the crank revolution corresponding to the relevant movement of the piston, valve timing diagrams are made.The valve timing diagram comprises of a 360 degree figure which represents the movement of the piston from TDC to BDC in all the strokes of the engine cycle, Which is measured in degrees and the opening and closing of the valves is controlled according to these degrees. What is the need for Valve Timing Diagram ?A normal engine works such that it completes approximately 1,00,000+ cycles per minute. Hence it is mandatory to monitor & supervise a system which can enable :-

• Providing engine with a mixer of air and fuel or simply pure air in case of diesel engine when required ( at the time of suction) which is the necessity of the engine.
• Complete seizure of the combustion chamber at the instant at which the combustion of air-fuel mixture takes place as the leakage can cause damage to the engine and can be hazardous as well.
• Synchronization between the steps of a cycle of the engine from intake of air-fuel ratio to the exhaust of combustion residual (Burnt gases).
• Ideal timing for the opening and closing of the inlet and outlet valve which in turn protect the engine from defects like knocking or detonation.
• A high compression ratio required to ignite the fuel especially in case of diesel engine by overlapping the closing of the valve (Valve overlapping).
• The study of the details of the combustion that is required for the modification of the power of the engine.
• The cleaning of engine cylinder which in turn maintain the quality of combustion and decreases wear and tear inside the cylinder.

Hence for these many reasons, engines (whether they are 2 or 4 stroke) are designed keeping valve timing diagram meticulous & accordingly. So that the movement of piston from TDC to BDC is provided with the ideal timing of opening and closing of the intake and exhaust valves respectively. This lecture covers the basics of making & understanding the theoretical valve timing diagram of two & four stroke cycle internal combustion engines. Sequence of operation. Each stroke in IC engines forms a sequence of operations in one cycle of an IC Engines i.e suction stroke, compression stroke, expansion stroke, and exhaust stroke. When an engine is working continuously, we can consider a cycle starting from any stroke. We know that when the engine returns back to the stroke where it started, we say that one cycle has completed. The following sequence of operation in a cycle is widely used. Suction stroke :- In this stroke, the fuel vapor in correct proportion, is supplied to the engine cylinder. Compression stroke :- In this stroke, the fuel vapor is compressed in the engine cylinder. Expansion or working stroke :- In this stroke, the fuel vapor is fired just before the compression is complete. It results in the sudden rise of pressure, due to expansion of the combustion products in the engine cylinder. This sudden rise of pressure pushes the piston with a great force and rotates the crankshaft. The crankshaft, in turn, drives the machine connected to it. Exhaust stroke :- In this stroke, the burnt gases (or combustion products) are exhausted from the engine cylinder, so as to make space available for the fresh fuel vapor. Introduction. 4 lectures 30:14 Introduction to IC engines & their classifications. Internal Combustion Engines are heat engines in which combustion takes place inside of engine cylinder with an oxidizer (generally air). Internal combustion heat engines work on the principle of the ideal gas law: pV=nRT. (Ideal gas law) An internal combustion engine has a chamber, which has fuel added to it which ignites in order to raise the temperature of the gas.When heat is added to the system, it forces gas inside to expand, this causes the piston to rise, and in case of a gas turbine, the hot air is forced into the turbine chamber...By attaching the piston or turbine to a camshaft, the engine is able to convert a portion of the energy input to the system into useful work.To compress the piston in an intermittent combustion engine, the engine exhausts the gas. A heat sink is then used to keep the system running at a consistent temperature. A gas turbine, which uses continuous combustion, simply exhausts its gas continuously rather than in a cycle. The classification of IC engines is covered in this lecture along with basic introduction. Main components of I.C.engine. What are the components which makes an IC engine.... The answer is hundreds of. Out of these many components, we are going to have a discussion regarding cylinder,cylinder head,piston,piston rings,connecting rod,crankshaft & other major components.A brief description about each of these major components are enlisted below ; Cylinder - Cylinder is the main body of IC engine. Cylinder is a part in which the intake of fuel, compression of fuel and burning of fuel take place. The main function of cylinder is to guide the piston. Cylinder head - One end of the cylinder is closed by means of cylinder head. This consists of inlet valve for admitting air fuel mixture and exhaust valve for removing the products of combustion.The inlet valve, exhaust valve, spark plug, injector etc. are bolted on the cylinder head. The main function of cylinder head is to seal the cylinder block and not to permit entry and exit of gases on cover head valve engine.Generally made up of aluminium alloys. Piston - It transmits the energy to crankshaft through connecting rod. Piston rings - These are used to maintain a pressure tight seal between the piston and cylinder walls and also it transfer the heat from the piston head to cylinder walls.These rings are fitted in grooves which have been cut in the piston. They are split at one end so they can expand or slipped over the end of piston.Generally made of highly elastic material or fine grain cast iron. Connecting Rods - One end of the connecting rod is connected to piston through piston pin while the other is connected to crank through crank pin.It transmits the reciprocatory motion of piston to rotary crank."Big end of the connecting rod is connected to the crankshaft and the small end is connected to the piston by using piston pin".Generally made of low carbon steels. Crank - A lever between connecting rod and crank shaft. Crank Shaft - The function of crank shaft is to transform reciprocating motion in to a rotary motion.The crankshaft of an internal combustion engine receives the efforts or thrust supplied by piston to the connecting rod and converts the reciprocating motion of piston into rotary motion of crankshaft.The crankshaft mounts in bearing so it can rotate freely."The shape and size of crankshaft depends on the number and arrangement of cylinders." Valve timing diagrams. A valve timing diagram is a graphical representation of the opening and closing of the inlet (Intake) and outlet (Exhaust) valve of the engine, The opening and closing of the valves of the engine depend upon the movement of piston from TDC (Top Dead Center) to BDC (Bottom Dead Center). Encapsulating the crank revolution corresponding to the relevant movement of the piston, valve timing diagrams are made.The valve timing diagram comprises of a 360 degree figure which represents the movement of the piston from TDC to BDC in all the strokes of the engine cycle, Which is measured in degrees and the opening and closing of the valves is controlled according to these degrees. What is the need for Valve Timing Diagram ?A normal engine works such that it completes approximately 1,00,000+ cycles per minute. Hence it is mandatory to monitor & supervise a system which can enable :-

• Providing engine with a mixer of air and fuel or simply pure air in case of diesel engine when required ( at the time of suction) which is the necessity of the engine.
• Complete seizure of the combustion chamber at the instant at which the combustion of air-fuel mixture takes place as the leakage can cause damage to the engine and can be hazardous as well.
• Synchronization between the steps of a cycle of the engine from intake of air-fuel ratio to the exhaust of combustion residual (Burnt gases).
• Ideal timing for the opening and closing of the inlet and outlet valve which in turn protect the engine from defects like knocking or detonation.
• A high compression ratio required to ignite the fuel especially in case of diesel engine by overlapping the closing of the valve (Valve overlapping).
• The study of the details of the combustion that is required for the modification of the power of the engine.
• The cleaning of engine cylinder which in turn maintain the quality of combustion and decreases wear and tear inside the cylinder.

Hence for these many reasons, engines (whether they are 2 or 4 stroke) are designed keeping valve timing diagram meticulous & accordingly. So that the movement of piston from TDC to BDC is provided with the ideal timing of opening and closing of the intake and exhaust valves respectively. This lecture covers the basics of making & understanding the theoretical valve timing diagram of two & four stroke cycle internal combustion engines. Sequence of operation. Each stroke in IC engines forms a sequence of operations in one cycle of an IC Engines i.e suction stroke, compression stroke, expansion stroke, and exhaust stroke. When an engine is working continuously, we can consider a cycle starting from any stroke. We know that when the engine returns back to the stroke where it started, we say that one cycle has completed. The following sequence of operation in a cycle is widely used. Suction stroke :- In this stroke, the fuel vapor in correct proportion, is supplied to the engine cylinder. Compression stroke :- In this stroke, the fuel vapor is compressed in the engine cylinder. Expansion or working stroke :- In this stroke, the fuel vapor is fired just before the compression is complete. It results in the sudden rise of pressure, due to expansion of the combustion products in the engine cylinder. This sudden rise of pressure pushes the piston with a great force and rotates the crankshaft. The crankshaft, in turn, drives the machine connected to it. Exhaust stroke :- In this stroke, the burnt gases (or combustion products) are exhausted from the engine cylinder, so as to make space available for the fresh fuel vapor. Introduction to IC engines & their classifications. Internal Combustion Engines are heat engines in which combustion takes place inside of engine cylinder with an oxidizer (generally air). Internal combustion heat engines work on the principle of the ideal gas law: pV=nRT. (Ideal gas law) An internal combustion engine has a chamber, which has fuel added to it which ignites in order to raise the temperature of the gas.When heat is added to the system, it forces gas inside to expand, this causes the piston to rise, and in case of a gas turbine, the hot air is forced into the turbine chamber...By attaching the piston or turbine to a camshaft, the engine is able to convert a portion of the energy input to the system into useful work.To compress the piston in an intermittent combustion engine, the engine exhausts the gas. A heat sink is then used to keep the system running at a consistent temperature. A gas turbine, which uses continuous combustion, simply exhausts its gas continuously rather than in a cycle. The classification of IC engines is covered in this lecture along with basic introduction. Introduction to IC engines & their classifications. Internal Combustion Engines are heat engines in which combustion takes place inside of engine cylinder with an oxidizer (generally air). Internal combustion heat engines work on the principle of the ideal gas law: pV=nRT. (Ideal gas law) An internal combustion engine has a chamber, which has fuel added to it which ignites in order to raise the temperature of the gas.When heat is added to the system, it forces gas inside to expand, this causes the piston to rise, and in case of a gas turbine, the hot air is forced into the turbine chamber...By attaching the piston or turbine to a camshaft, the engine is able to convert a portion of the energy input to the system into useful work.To compress the piston in an intermittent combustion engine, the engine exhausts the gas. A heat sink is then used to keep the system running at a consistent temperature. A gas turbine, which uses continuous combustion, simply exhausts its gas continuously rather than in a cycle. The classification of IC engines is covered in this lecture along with basic introduction C engine. Cylinder is a part in which...