Auto-ignition during instationary jet evolution of dimethyl ether (DME) in a high-pressure atmosphere

Experiments and Simulations of n-Heptane Spray Auto-Ignition in a Closed Combustion Chamber at Diesel Engine Conditions

“…This is in contrast to the findings reported in [6], where strong variability was reported which was attributed to small spatial and temporal temperature in-homogeneities, estimated to be of the order of 20 K. In [7], the statistical analysis of around 200 repetitions of auto-igniting n-octane sprays in a shock-tube also showed a significant spread of the induction period around the mean. For autoigniting jets of gaseous DME presented in [61], the 95% confidence intervals for the ignition delays amounted to roughly a quarter of the total delay. For the model engine in [1], ignition delays and their standard deviations averaged from roughly 100 cycles are reported for nine different operating conditions.…”

“…For engines with multi-hole nozzles on the other hand, one single injection event for a given engine cycle provides a 'collection' of autoignition sites for each of the fuel sprays (which are at 'identical' thermodynamic conditions), as can be observed in the study of [4], where the influence of cycleto-cycle variations is additionally presented. In [61], investigations of the mixture fraction distribution of gaseous DME jets by means of LIF enabled the calculation of discrete mixture fraction PDFs. Conjectures employing the flammability limits of the fuel allowed for a subsequent derivation of iso-contours indicating a local ignition probability.…”

The role of temperature, mixture fraction, and scalar dissipation rate on transient methane injection and auto-ignition in a jet in hot coflow burner

“…The ignition was observed to occur near the tip of the exhaust gas jet and no ignition was observed at the periphery of the jet, where the strain rate is expected to be high. Fast et al [23] studied the auto-ignition of a transient dimethyl ether jet in a high-pressure environment using high-speed shadowgraphy imaging. They observed a two-stage ignition process.…”

“…Gordon et al [15] observed isolated ignition kernels corresponding to a rise of temperature and CH 2 O concentration; however, OH was not present in all ignition kernels, indicating auto-ignition (and not flame propagation) is a primary mechanism behind lifted flame stabilization. With the recent development of high-speed laser measurement and imaging techniques [19][20][21] , new insights into the mechanisms governing auto-ignition has been gained in transient systems [17,[22][23][24][25][26][27][28][29][30][31] . In the current work, high-speed laser-based measurements are used to reveal details of the roles of temperature, mixture fraction, and scalar dissipation rate on auto-ignition within a JHC configuration.…”

Energy-Saving Lipid Extraction from Wet Euglena gracilis by the Low-Boiling-Point Solvent Dimethyl Ether

“…In addition, DME has been developed as a synthetic fuel for use in both liquid and gaseous forms. In China, DME is synthesized using small-scale coalfields of low commercial value and produced as a fuel at a cost equivalent to that of imported liquefied petroleum gas [17][18][19]. The boiling point of DME is −24.8 °C and its saturated vapor pressure at 20 °C is 0.51 MPa [20].…”