Numerical investigation of the effect of obstacle shape on deflagration to detonation transition in a hydrogen-air mixture

被引:58
作者
Coates, Ashley M. [1 ,2 ]
Mathias, Donovan L. [1 ]
Cantwell, Brian J. [2 ]
机构
[1] NASA, Ames Res Ctr, MS 258-5, Moffett Field, CA 94035 USA
[2] Stanford Univ, Aeronaut & Astronaut, 496 Lomita Mall, Stanford, CA 94305 USA
关键词
Combustion; Deflagration; Detonation; Hydrogen; Simulation; FLAME ACCELERATION; DDT; CHANNELS; PROPAGATION; SIMULATION;
D O I
10.1016/j.combustflame.2019.07.044
中图分类号
O414.1 [热力学];
学科分类号
摘要
The potential for deflagration to detonation transition (DDT) in an uncontained failure poses extreme risk to nearby personnel. This study performs numerical simulations with detailed chemistry models of confined stoichiometric hydrogen-air mixtures interacting with flow obstructions to better understand the mechanisms of detonation initiation which will inform future risk assessments. Unique obstacle geometries, including both rectangular and curved obstacles, are considered in an effort to isolate important contributors to DDT. Contributors are shown to be pressure wave interactions in unburned fuel and flow features, such as vortical structures, which encourage flame acceleration. In this study, detonation was only observed in cases with sharp-edged obstacles and not in smooth-walled cases. The sharp edges introduced vortex shedding which contributed to flame distortion and resulted in acceleration. In addition, detonation was observed where strong pressure waves and reflections interacted in unburned fuel. The variations in geometry within the sharp-edged obstacles had some effect on vortex shedding and the reflections of generated shocks resulting in small changes in detonation location, however, the mechanism of DDT appeared the same, and the changes were small in comparison to the smooth-walled cases which did not detonate. Published by Elsevier Inc. on behalf of The Combustion Institute.
引用
收藏
页码:278 / 290
页数:13
相关论文
共 35 条
[1]  
Allgood D., 2016, NASATP2016219220 NTR
[2]  
Chapin D., 2005, THESIS
[3]   Flame acceleration and transition to detonation in ducts [J].
Ciccarelli, G. ;
Dorofeev, S. .
PROGRESS IN ENERGY AND COMBUSTION SCIENCE, 2008, 34 (04) :499-550
[4]   INFLUENCE OF CHEMICAL-KINETICS AND UNMIXEDNESS ON BURNING IN SUPERSONIC HYDROGEN FLAMES [J].
EVANS, JS ;
SCHEXNAYDER, CJ .
AIAA JOURNAL, 1980, 18 (02) :188-193
[5]   Experimental and numerical investigation of DDT in hydrogen-Air behind a single obstacle [J].
Gaathaug, Andre Vagner ;
Vaagsaether, Knut ;
Bjerketvedt, Dag .
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 2012, 37 (22) :17606-17615
[6]   Flame acceleration and DDT in channels with obstacles: Effect of obstacle spacing [J].
Gamezo, Vadim N. ;
Ogawa, Takanobu ;
Oran, Elaine S. .
COMBUSTION AND FLAME, 2008, 155 (1-2) :302-315
[7]   Numerical simulations of flame propagation and DDT in obstructed channels filled with hydrogen-air mixture [J].
Gamezo, Vadim N. ;
Ogawa, Takanobu ;
Oran, Elaine S. .
PROCEEDINGS OF THE COMBUSTION INSTITUTE, 2007, 31 :2463-2471
[8]   Shock transition to detonation in channels with obstacles [J].
Goodwin, G. B. ;
Houim, R. W. ;
Oran, E. S. .
PROCEEDINGS OF THE COMBUSTION INSTITUTE, 2017, 36 (02) :2717-2724
[9]   Effect of decreasing blockage ratio on DDT in small channels with obstacles [J].
Goodwin, G. B. ;
Houim, R. W. ;
Oran, E. S. .
COMBUSTION AND FLAME, 2016, 173 :16-26
[10]   Numerical simulation of flame acceleration and deflagration to detonation transition in hydrogen-air mixture [J].
Heidari, A. ;
Wen, J. X. .
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 2014, 39 (36) :21317-21327