Ignition delay times of methane/diethyl ether (DEE) blends measured in a rapid compression machine (RCM)

Diethyl ether (DEE) is an interesting species for combustion for at least two reasons: On the one hand, it is used as a kind of "worst case" reference substance for studies concerned with the prevention of accidental ignition events. On the other hand, it is also a candidate bio-fuel. For this reason, in this work, auto-ignition of two different CH$_{4}$/DEE-mixtures (90/10 and 95/5 mol-% CH$_{4}$/DEE) are studied in a rapid compression machine (RCM). In the RCM, the gas mixture is compressed in a piston-cylinder device up to 20 bar and held under isochoric conditions at top dead center. Autoignition occurs after an ignition delay time (IDT). IDTs are measured for compression temperatures ranging between 515 and 925 K, for both, stoichiometric and fuel-rich mixtures (equivalence ratio $\phi$ = 2). The experimental data are compared to results of simulations involving detailed chemistry, as well as to other fuels investigated in the same RCM (results from literature).