Autoignition and detonation characteristics of n-heptane/air mixture with water droplets

Zhuang, Yijie1; Li, Qiang1; Dai, Peng2; Zhang, Huangwei1

2020

10.1016/j.fuel.2020.117077

FUEL   影响因子和分区

0016-2361

1873-7153

The present study addresses the autoignition and detonation characteristics of n-heptane/air mixture with water droplets in a confined one-dimensional reactor. A Eulerian-Eulerian formulation for gas and liquid phases is employed to simulate multi-component, fully compressible and reactive multi-phase flows. The parametric investigations covering a range of droplet diameters and number densities are conducted to understand the reaction front development in gas phase and droplet evaporation characteristics under different gaseous combustion conditions. Four modes of autoignition behaviours in the reactor are identified and they are found to greatly depend on both droplet diameter and number density. At a relatively small droplet diameter and/or number density, detonation is initiated by hot spot but no autoignition occurs at the right boundary. When both or either of them increase, autoignition occurs at the right boundary and the reaction front may further evolve into detonative or deflagrative waves. This is because the temperature inhomogeneity in that region is considerably enhanced. Furthermore, droplet diameter and number density are used to quantify the different modes of autoignition and detonation development. For the droplet evaporation dynamics during the reactive front development process, various mechanisms are observed, related to the different effects dominated by the velocity difference between two phases (characterized by the droplet Reynolds number), high local gas pressure and also the droplet temperature. This results in non-monotonic spatial distributions of droplet evaporation rate in the reactor, e.g. M-shaped in the detonated or shocked regions.
© 2020 Elsevier Ltd

Autoignition Detonation development n-heptane/air Water droplet evaporation Thermal inhomogeneity

SCI ; EI

英语

通讯

National University of Singapore[R-265-000-604-133] ; National Natural Science Foundation of China[]

Energy & Fuels ; Engineering

Energy & Fuels ; Engineering, Chemical

WOS:000510603500010

Elsevier Ltd

20200408082507

Combustion knock ; Detonation ; Evaporation ; Heptane ; Mixtures ; Reynolds number

Fuel Combustion:521.1 ; Fluid Flow, General:631.1 ; Chemical Operations:802.3 ; Organic Compounds:804.1

ENGINEERING

Web of Science

1.Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore; 117576, Singapore
2.Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen; 518055, China

Zhuang, Yijie,Li, Qiang,Dai, Peng,et al. Autoignition and detonation characteristics of n-heptane/air mixture with water droplets[J]. FUEL,2020,266.

Zhuang, Yijie,Li, Qiang,Dai, Peng,&Zhang, Huangwei.(2020).Autoignition and detonation characteristics of n-heptane/air mixture with water droplets.FUEL,266.

Zhuang, Yijie,et al."Autoignition and detonation characteristics of n-heptane/air mixture with water droplets".FUEL 266(2020).