What are the four phases of combustion?
An internal-combustion engine goes through four strokes: intake, compression, combustion (power), and exhaust.
What is normal combustion in CI engine?
The combustion is normal when 2 conditions are respected: 1) the ignition of combustible mixture is controlled by the spark plug, with a present timing 2) after the ignition, the flame propagates regularly to the whole mixture, without any sudden increase of velocity.
What is delay period in CI engine?
Abstract. The ignition delay in a diesel engine is defined as the time interval between the start of injection and the start of combustion. This delay period consists of (a) physical delay, wherein atomisation, vaporization and mixing of air fuel occur and (b) of chemical delay attributed to pre-combustion reactions.
How much pressure does it take to ignite diesel?
Diesel engines have no spark plugs to ignite the fuel. In the cylinder, the pressure is so great the temperature is very high. The pressure is so great (16:1 or 234 psi) that the temperature becomes high enough to ignite the fuel without a spark plug.
What does the blue smoke in diesel engine indicate?
What does the blue smoke in diesel engine indicate? Explanation: Blue smoke comes out from the exhaust when there is unburnt oil in the diesel engine. A very thin layer of the oil gets deposited on the cylinder wall to provide the lubrication between the walls and the moving piston.
What is the normal combustion?
In normal combustion, the piston is on its way up the cylinder toward Top Dead Center. It’s compressing a mixture of fuel and air above it. At a point, before TDC, a spark passes across the gap of the spark plug electrodes and that sets the mixture to burning, creating a tiny flame kernel.
What is abnormal combustion?
In Internal combustion engines, abnormal combustion is a significant phenomenon associated with the combustion processes on which the life and performance of the engine depends. The two important abnormal combustion phenomenons are 1. KNOCK and 2. SURFACE IGNITION.