What is Engine Knock?

[ColeRose]

Under certain conditions, the combustion in a gasoline engine can become abnormal, with the pressure curve exhibiting high-frequency and large-amplitude fluctuations. The dp/dt value near the top dead center fluctuates sharply, reaching as high as (dp/dt)max=0.2Mpa/us. At this point, the flame propagation speed and the shape of the flame front undergo drastic changes. This phenomenon is known as engine knock. Below is a detailed introduction to automobile engines: 1. Overview: The automobile engine is the device that provides power to the car, determining its power, fuel economy, stability, and environmental performance. Depending on the power source, automobile engines can be classified into diesel engines, gasoline engines, electric vehicle motors, and hybrid systems, among others. 2. Others: Common gasoline and diesel engines are both reciprocating piston internal combustion engines, capable of converting the chemical energy of fuel into the mechanical energy of piston motion and outputting power externally. Gasoline engines feature high rotational speed, small mass, low noise, easy starting, and low manufacturing costs. Diesel engines have a high compression ratio, high thermal efficiency, and better fuel economy and emission performance than gasoline engines.