Tihendusastetena

Tihendusastetena refers to the compression ratio in internal combustion engines. It is a fundamental parameter that describes the relationship between the volume of the cylinder at the bottom dead center and the volume at the top dead center. Specifically, it is the ratio of the total cylinder volume (swept volume plus clearance volume) to the clearance volume. A higher compression ratio generally leads to increased thermal efficiency, meaning more of the fuel's energy is converted into mechanical work. This is because the higher compression increases the pressure and temperature of the air-fuel mixture before ignition, resulting in a more powerful expansion stroke. However, excessively high compression ratios can lead to engine knocking or detonation, a phenomenon where uncontrolled combustion occurs, potentially damaging the engine. Engine designers must carefully balance the benefits of higher compression ratios with the risk of knocking. Different types of engines and fuels have optimal compression ratios. For instance, gasoline engines typically have lower compression ratios than diesel engines. The octane rating of gasoline is directly related to its ability to withstand higher compression ratios without knocking.