Autoignition and detonation development from a hot spot inside a closed chamber: Effects of end wall reflection

Dai，Peng1; Chen，Zheng2; Gan，Xiaohua1; Liberman，Mikhail A.3

2020

10.1016/j.proci.2020.09.025

PROCEEDINGS OF THE COMBUSTION INSTITUTE   影响因子和分区

1540-7489

1873-2704

The advancement of highly boosted internal combustion engines (ICEs) with high thermal efficiency is mainly constrained by knock and super-knock, respectively, due to the end gas autoignition and detonation development. The pressure wave propagation and reflection in a small confined space may strongly interact with local end gas autoignition, leading to combustion characteristics different from those in a large chamber or open space. The present study investigates the transient autoignition process in an iso-octane/air mixture inside a closed chamber under engine-relevant conditions. The emphasis is given to the assessment of effects of the pressure wave-wall reflection and the mechanism of extremely strong pressure oscillation typical for super-knock. It is found that the hot spot induced autoignition in a closed chamber can be greatly affected by shock/pressure wave reflection from the end wall. Different autoignition modes respectively from the hot spot and the end wall reflection are identified. A non-dimensional parameter quantifying the interplay between different length and time scales is introduced, which helps to identify different autoignition regimes including detonation development near the end wall. It is shown that detonation development from the hot spot may cause super-knock with devastating pressure oscillation. However, the detonation development from the end wall can hardly produce pressure oscillation strong enough for the super-knock. The obtained results provide a fundamental insight into the knocking mechanism in engines under highly boosted conditions.

Autoignition Detonation development End wall reflection Iso -octane Pressure oscillation

EI ; SCI

英语

第一 ; 通讯

NSFC[51976088,51606091] ; Shenzhen SciTech Fund[JCYJ20180302173952945]

Thermodynamics ; Energy & Fuels ; Engineering

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

WOS:000640387700008

ELSEVIER SCIENCE INC

20204809533349

Combustion ; Detonation ; Wave propagation

Fuel Combustion:521.1

ENGINEERING

2-s2.0-85096468726

Scopus

1.Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen 518055, China
2.SKLTCS, CAPT, BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
3.Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden

Dai，Peng,Chen，Zheng,Gan，Xiaohua,et al. Autoignition and detonation development from a hot spot inside a closed chamber: Effects of end wall reflection[J]. PROCEEDINGS OF THE COMBUSTION INSTITUTE,2020,38(4):5905-5913.

Dai，Peng,Chen，Zheng,Gan，Xiaohua,&Liberman，Mikhail A..(2020).Autoignition and detonation development from a hot spot inside a closed chamber: Effects of end wall reflection.PROCEEDINGS OF THE COMBUSTION INSTITUTE,38(4),5905-5913.

Dai，Peng,et al."Autoignition and detonation development from a hot spot inside a closed chamber: Effects of end wall reflection".PROCEEDINGS OF THE COMBUSTION INSTITUTE 38.4(2020):5905-5913.