Enabling robust simulation of polyoxymethylene dimethyl ether 3 (PODE3) combustion in engines

Abstract

PODE3 reaction mechanism developments are still in the early stages with very limited research. In particular, reaction mechanisms to characterize PODE3 combustion are neither sufficiently compact nor robust for 3D numerical simulations. Hence, the current work seeks to develop a compact yet reliable PODE3 reaction mechanism, embedded with appropriate chemistry to describe polycyclic aromatic hydrocarbon reactions. A decoupling methodology has been employed to achieve the desired outcome. The final mechanism comprises only 120 species and 560 reactions even after including components of diesel and gasoline surrogates. It has been validated with ignition delay times, laminar flame speeds, jet-stirred reactor species concentration profiles, flame species concentration profiles, extinction strain rates, heat release rates in constant volume combustion chamber, homogeneous charge compression ignition engine combustion, and direct injection compression ignition engine combustion. In a numerical investigation conducted using gasoline/diesel/PODE3 blends, soot emissions are observed to decrease with PODE3 increment, which establishes PODE3 as a promising additive. Intriguingly, the current study has also discovered that with 15% PODE3 addition, soot and its precursors will increase in concentration during combustion, though this effect will be outweighed by oxidative effects towards the end. Overall, the new mechanism has been proven suitable and feasible for engine simulations.