내연기관 연소실내에서 이온전류의 발진특성에 관한 연구

A study on oscillation characteristics of ionization current in internal combustion chamber

The measurement of ionization current (IC) in internal combustion engine (ICE) cylinder is one of perspective methods of combustion control. There are a number of researches utilizing the ionization probe as a sensor for the burning quality measurement and knocking regime detection in spark ignition engine (SIE) and diesel engine (DE). The spark plug and glow plug as ionization probe can be used for spark ignition engine and diesel engine. It is known that the peak of chemical ionization of combustion products occurs immediately behind front flame when front flame propagates through fuel-air mixture. The electrical conductivity of combustion products sharply increases in the range of peak. The combustion processes and the moving of combustion products in cylinder are accompanied as a rule by oscillation phenomena. In this paper, the nature of these oscillation is analyzed by comparing of pressure and IC measurements. It is shown that the principle oscillation of regular type as entropy waves. acoustic oscillation and relaxation oscillation when gas flows from half-closed volume(for example from DE prechamber) can exit in cylinder.