HCCI
HCCI, or Homogeneous Charge Compression Ignition, is a concept for internal combustion engines in which a nearly uniform air–fuel mixture is compressed to reach the conditions for autoignition. Ignition occurs without a spark plug or a propagating flame front, driven by chemical kinetics and the in-cylinder temperature and pressure. The aim is a smooth, near-simultaneous combustion of the entire charge rather than localized flame propagation.
In operation, the charge is prepared close to premixing and then compressed until autoignition occurs. Because
Advantages of HCCI include potential for high thermal efficiency at lean operation and very low emissions
Challenges center on controllability and stability: narrow and variable operating ranges, sensitivity to fuel quality and
Today, HCCI remains largely a research and development area, with demonstrations in automotive and heavy-duty contexts,