Effects of initial temperature on autoignition and detonation development in dimethyl ether/air mixtures with temperature gradient

Dai, Peng1,2; Qi, Chengken2; Chen, Zheng2

2017

10.1016/j.proci.2016.08.014

PROCEEDINGS OF THE COMBUSTION INSTITUTE   影响因子和分区

1540-7489

1873-2704

For large hydrocarbon fuels used in internal combustion engines, different low-temperature and high-temperature chemistries are involved in the autoignition processes under different initial temperatures. As one of the simplest fuels with low-temperature chemistry, dimethyl ether (DME) is considered in this study and one-dimensional autoignitive reaction front propagation induced by temperature gradient is simulated for stoichiometric DME/air mixtures considering detailed chemistry and transport. The emphasis is placed on assessing and interpreting the influence of initial temperature on the detonation development regime. Different initial temperatures below, within and above the negative-temperature coefficient (NTC) region are considered. For each initial temperature, four typical autoignition modes are identified: supersonic autoignitive reaction front (without detonation); detonation development; transonic reaction front; and sub-sonic reaction front. The detonation development regimes for two fuels, DME and n-heptane, at the same initial temperature and those for the same fuel, DME, at three different initial temperatures respectively be-low, within and above the NTC region are obtained. Based on these results, the influence of fuel type and initial temperature on detonation development regime are discussed. It is found that the detonation development regime becomes narrower at higher initial temperature. Moreover, the influence of initial temperature on reaction front propagation speed is investigated. The reaction front propagation speed is shown to be strongly affected by different chemistries involved in low and high temperature regions. When only the high-temperature chemistry is involved, the reaction front propagation speed is shown to be less dependent on the initial temperature. (C) 2016 by The Combustion Institute. Published by Elsevier Inc.

Autoignition Detonation Temperature gradient Dimethyl ether

SCI ; EI

英语

第一

China Postdoctoral Science Foundation[2015M570011]

Thermodynamics ; Energy & Fuels ; Engineering

Thermodynamics ; Energy & Fuels ; Engineering, Chemical ; Engineering, Mechanical

WOS:000393412600035

ELSEVIER SCIENCE INC

20164903097460

Detonation ; Ethers ; Thermal gradients

Thermodynamics:641.1 ; Organic Compounds:804.1

ENGINEERING

Web of Science

1.South Univ Sci & Technol China, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
2.Peking Univ, Coll Engn, Dept Mech & Engn Sci, SKLTCS, Beijing 100871, Peoples R China

Dai, Peng,Qi, Chengken,Chen, Zheng. Effects of initial temperature on autoignition and detonation development in dimethyl ether/air mixtures with temperature gradient[J]. PROCEEDINGS OF THE COMBUSTION INSTITUTE,2017,36(3):3643-3650.

Dai, Peng,Qi, Chengken,&Chen, Zheng.(2017).Effects of initial temperature on autoignition and detonation development in dimethyl ether/air mixtures with temperature gradient.PROCEEDINGS OF THE COMBUSTION INSTITUTE,36(3),3643-3650.

Dai, Peng,et al."Effects of initial temperature on autoignition and detonation development in dimethyl ether/air mixtures with temperature gradient".PROCEEDINGS OF THE COMBUSTION INSTITUTE 36.3(2017):3643-3650.