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论文类型：期刊论文

发表时间：2014-12-03

发表刊物：INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

收录刊物：SCIE、EI、Scopus

卷号：39

期号：35

页面范围：20503-20508

ISSN号：0360-3199

关键字：Spontaneous ignition; Shock reflection; Numerical simulation

摘要：Spontaneous ignition of compressed hydrogen release through a length of tube with different internal geometries is numerically investigated using our previously developed model. Four types of internal geometries are considered: local contraction, local enlargement, abrupt contraction and abrupt enlargement. The presence of internal geometries was found to significantly increase the propensity to spontaneous ignition. Shock reflections from the surfaces of the internal geometries and the subsequent shock interactions further increase the temperature of the combustible mixture at the contact region. The presence of the internal geometry stimulates turbulence enhanced mixing between the shock-heated air and the escaping hydrogen, resulting in the formation of more flammable mixture. It was also found that forward-facing vertical planes are more likely to cause spontaneous ignition by producing the highest heating to the flammable mixture than backward-facing vertical planes. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.