Question

In the CI engine, the intake is air alone and the fuel is injected at high pressure in the form of fine droplets at the start of compression.

(a) True

(b) False

I got this question in a national level competition.

I want to ask this question from Combustion in C.I. Engine topic in chapter Combustion and Combustion Chambers of IC Engine

Answer 1

The correct answer is:

(b) False

Explanation: In a Compression Ignition (C.I.) engine, the fuel is not injected at the start of compression. Instead, the intake air is drawn in during the intake stroke, and then, towards the end of the compression stroke, fuel is injected into the highly compressed, hot air at high pressure. The fuel is injected in the form of fine droplets, and this injection process initiates combustion due to the high temperature of the air. The key point is that fuel injection happens at the end of the compression stroke, not at the start.