HC4-2: Numerical Analysis of Miller-PCCI Combustion on a Dynamic φ-T Map(HC: HCCI Combustion,General Session Papers)

Abstract

A variable valve timing (VVT) mechanism has been applied in a high-speed direct injection (HSDI) diesel engine. The effective compression ratio (ε_<eff>) was lowered by means of late intake valve closing (LIVC), while keeping the expansion ratio constant. Premixed charge compression ignition (PCCI) combustion, adopting the Miller-cycle, was experimentally realized and numerically analyzed. Significant improvements of NO_x and soot emissions were achieved for a wide range of engine speeds and loads, frequently used in a transient mode test. The operating range of the Miller-PCCI combustion has been expanded up to an IMEP of 1.30 MPa.