COMSOL Verification and Validation Models

Homogeneous Charge Compression Ignition (HCCI) engines are being considered as an alternative to traditional spark- and compression-ignition engines. As the name implies, a homogeneous fuel/oxidant mixture is auto-ignited by compression with simultaneous combustion occurring throughout the cylinder volume. Combustion temperatures under lean burn operation are relatively low, resulting in low levels of NOx emission. Furthermore, the fuel’s homogeneous nature as well as the combustion process itself lead to low levels of particulate matter being produced.

Although HCCI combustion shows much promise, the method also suffers from a number of recurring problems, one of the more important being ignition timing. The following model examines the HCCI of methane, investigating ignition trends as a function of initial temperature, initial pressure, and fuel additives.

This model solves the reaction kinetics, mass, and energy balances describing the detailed combustion of methane in a variable-volume system. The large amount of kinetic and thermodynamic data required to set up the problem is readily made available by importing relevant files on the CHEMKIN format into the Reaction Engineering interface.