Why thermal efficiency of four stroke engine is higher than two-stroke engines?
Due to the unique crankshaft design of the Atkinson, its expansion ratio can differ from its compression ratio and, with a power stroke longer than its compression stroke, the engine can achieve greater thermal efficiency than a traditional piston engine.
Which cycle has a higher thermal efficiency 4 stroke or 2 stroke?
Relatively 2 stroke engine of same physical size with 4 stroke engine, produces higher amount of power than that by 4 stroke engine. But in term of thermal efficiency, 2 stroke engine are considered less thermal efficient than 4 stroke engine.
Why thermal efficiency of two-stroke engine is less?
Less mechanical efficiency due to more friction in many parts. More mechanical efficiency due to less friction on a few parts. 7. More output due to full fresh charge intake and full burnt gases exhaust.
Why is 4-stroke engine more efficient?
4 stroke engines have a cycle of intake, compression, power, exhaust, which is a more efficient process, resulting in a reduction in amount of fuel used to power the engine and fuel lost from the exhaust.
Which engines have higher thermal efficiency?
According to Popular Mechanics, the reason diesel engines have a higher thermal efficiency than gasoline engines is that of two factors: compression ratios and lean-burn combustion.
Which engine has highest efficiency 2 stroke or 4-stroke?
Compared to four stroke engines, two strokes are lighter, more efficient, have the ability to use lower-grade fuel, and more cost-efficient. Therefore, the lighter engines results in a higher power-to-weight ratio (more power for less weight).
Why is the efficiency of a 2 stroke SI engine less than that of a 4-stroke SI engine?
Hence, the compression ratio of this engine is lower than that of a four-stroke engine of the same dimensions. As the efficiency of an engine is directly proportional to its compression ratio, the efficiency of a two-stroke cycle engine is lower than that of a four-stroke cycle engine of the same size.
What is difference between 2stroke and 4stroke engine?
The main difference between a 4-stroke engine and a 2-stroke engine is that a 4-stroke engine goes through four stages, or two complete revolutions, to complete one power stroke, while a 2-stroke engine goes through 2 stages, or one complete revolution, to complete one power stroke.
What is the difference between SI and CI engine?
Difference Between Si engine and Ci engine
Si engine is internal combustion engine that operates on the principle of spark ignition. It uses petrol and utilizes the Otto cycle. The diesel (Ci) engine is also an internal combustion engine, which uses diesel fuel and operates on diesel cycle.
Why are 2-stroke engines more efficient?
The higher fuel consumption of a two stroke engine is mostly due to the fact that it has a power stroke per revolution of the crankshaft.