What Are The Advantages Of Lubrication In Ic Engine? During Idling Process, A Petrol Engine Requires Lean Or Rich Mixture?Ĩ. Because it has smaller size for the same output.ħ. Two stroke engine is generally preferred. Among Two-stroke Engine And Four-stroke Engine Which Is Generally Preferred And Why? are drawn in.įuel vapor and air are compressed and ignition takes place.įuel combustion takes place and piston is pushed downwards.Ħ. Name The Main Steps Involve In 4-stroke I.c Engine? It is the measure of rating of CI engine.ĥ. – Cetane number is defined as the percentage, by volume, of n-cetane in the mixture of n-cetane and alpha methyl naphthalene. It is the measure of rating of SI engine. – Octane number is defined as the percentage, by volume, of iso-octane in the mixture of iso-octane and h-heptane. Definition Of Octane Number And Cetane Number?
Ī four-stroke engine is an internal combustion engine in which the piston’s four separate strokes are required to complete single thermodynamic cycle.Ī 4-stroke engine is an internal combustion engine in which the piston completes four separate strokes- intake, compression, power, and exhaust- during two separate revolutions of the engine’s crankshaft, and one single thermodynamic cycle.Ĥ.
Mechanical Engineering Interview Questions The gas produced in this reaction rapidly expands forcing the piston down the cylinder on the power stroke.Ī Two-stroke engine is an internal combustion engine in which the piston’s two strokes are required to complete single thermodynamic cycle.Ģ-STROKE engine is designed by DUGLAD CLERK in 1880, the expansion and exhaust takes place during 2-Stroke of piston. Pay attention to piston position, valve position, the moment when the ignition occurs and the succession of the strokes.The internal combustion engine converts chemical energy into useful mechanical energy by burning fuel.Ĭhemical energy is released when the fuel-air mixture is ignited by the spark in the combustion chamber. In the animation below you can see clearly how the internal combustion engine works. The linear motion of the piston is transformed into rotational motion of the crankshaft through the connecting rod.įor a better understanding, we’re summarising the piston initial position, valve position and energy balance for each stroke. The only stroke which produces torque (energy) is the power stroke, all the others are consuming energy. This means that one engine cycles takes two complete rotations of the crankshaft (720°). The movement of the piston from the BDC towards the TDC pushes most of the exhaust gases out of the cylinder, into the exhaust pipes.ĭuring the exhaust stroke, the engine consumes energy (the crankshaft is rotating due to the inertia of the components).Īs you can see, in order to have a complete combustion (engine) cycle the piston has to perform 4 strokes. During this stroke, the exhaust valve is open. The exhaust stroke starts with the piston at the BDC, after the power stroke finished. Internal combustion engine exhaust stroke In the figure below we’ll have a look at the main moving part of an ICE, which transform the gas pressure within the cylinder in mechanical power. cylinder head, cylinder block) and some of them are moving. In Figure 1 we can examine the complete set of mechanical components of an ICE. The combustion chamber is the volume created between piston, cylinder head and engine block when the piston is close to TDC. The piston moves inside the cylinder from BDC to TDC. As for the cylinder head, through the engine block flows coolant to help control the temperature of the engine. Inside the engine block (12) we can find the piston, connecting rod and crankshaft. The cylinder head (8) usually contains the camshaft(s), valves, valve buckets, valve return springs, spark/glow plugs and injectors (for direct injection engines). Through the cylinder head flows the cooling liquid of the engine. Image: Internal combustion engine (DOHC) parts