What is ignition lag in petrol engine?
-point A shows the passage of spark and point B is the first rise of pressure. -ignition lag is generally expressed in terms of crank angle. -Ignition lag is very small and lies between 0.00015 to 0.0002 seconds. -ignition lag of 0.002 seconds corresponds to 35 deg crank rotation when the. engine is running at 3000 RPM.
Is ignition delay good or bad?
The shorter ignition delay affects the combustion performance of an engine. Ignition delay of the CI engine fuel is inversely proportional to its cetane number. Hence, optimization of ignition delay will improve the performance of the engine.
How do you reduce ignition delay?
Hence, if n 2 is somewhat increased prior to the fuel being exposed to oxygen, the observed ignition delay, τ, should decrease. According to the two energy level system, τ can be decreased simply by increasing the fuel temperature prior to injecting or exposing the fuel to oxygen.
What is meant by ignition delay?
The definition of ignition delay is the time lag between the start of injection to start of. the combustion when air-fuel mixture is ignited. In a diesel engine it can be deter- mined experimentally as the time interval between the start of injection and the. start of combustion (Fig.
What do you understand by ignition delay?
Ignition delay in a spark-ignition engine is generally defined as the time from spark initiation to the time when 10\% of the mass is burned.
What is ignition delay?
Ignition delay time is defined as the time between the arrival of the reflected shock wave and the onset of the ignition near the endwall. The arrival of the reflected shock wave was determined by the step rise in pressure at the sidewall (1 cm from endwall) observation location.
What is delay period and what are the factors that affect it?
I C ENGINES – II Air Motion & Combustion •Factors Affecting the Delay Period : – Intake temperature and pressure : Increase in intake temp. increases compressed air temp. resulting in reduced delay period. Preheating may not be desirable as it reduces density of air affecting volumetric efficiency and power.