What is the bespeak of high compression ratio?
Today every machine is expected to hand higher efficiency. When nosotros speak well-nigh petrol engine as well as diesel fuel engine whose thermal efficiency is straight related to 'compression ratio'. That agency if nosotros desire to compass higher thermal surgery inward price of efficiency, nosotros should supply high compression ratio for both the engine.
What is compression ratio?
The compression ratio is the ratio of full book of engine cylinder to the clearance book of the same cylinder. As the advert suggest, it relates compression of the air fuel mixture during compression stroke. When at that spot is compression, at that spot e'er move oestrus associated amongst as well as it increases the overall temperature of fuel air mixture.
Why compression ratio of petrol engine is kept depression compared to diesel fuel engine?
In petrol engine, petrol is used equally fuel as well as when it is subjected to high compression ratio, the oestrus generated may increment the temperature of petrol+air mixture inward a higher house the machine ignition temperature of petrol ( 280 °C) as well as the fuel mixture volition automatically ignite without getting sparked.
This machine ignition produces really high line per unit of measurement area which may flare-up piston. This phenomenon is called 'detonation'. So, to trim the detonation number as well as to permit the combustion inward precisely subsequently compression stroke, high compression ratio cannot move used inward petrol engine. In illustration of otto engines, the compression ratio is of the guild of iv to 8.