Numerical simulation for explosion wave propagation of combustible mixture gas

J Cent. South Univ Technol. (2008)15: 361-367DOI:10.1007/l1771-0080068-xNumerical simulation for explosion wave propagation ofcombustible mixture gasWANG Cheng(王成, NING Jian-guo(宁建国), MA Tian-bao(马天宝(State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology,Beijing 100081, China)Abstract: A two-dimensional multi-material code was indigenously developed to investigate the effects of duct boundary conditionsand ignition positions on the propagation law of explosion wave for hydrogen and methane-based combustible mixture gas In thecode, Youngs technique was employed to track the interface between the explosion products and air, and combustible function modelwas adopted to simulate ignition process. The code was employed to study explosion flow field inside and outside the duct and toobtain peak pressures in different boundary conditions and ignition positions. Numerical results suggest that during the propagationin a duct, for point initiation, the curvature of spherical wave front gradually decreases and evolves into plane wave due to themultiple reflections on the duct wall, multi-peak values appear on pressure-time curve, and peak pressure strongly relies on the ductemition model and multi-material interface treatment method are feasibleKey words: combustible mixture gas; explosion wave; interface treatment; combustion function modefront tracking method with a godunov-type solver fo1 Introductionthe Euler equations, BIELERT and SICHE2investigated the propagation process of detonation ofIn mining and other related industries, explosion ethylene/oxygen and methane/air mixtures at differentrelated accidents occur frequently, the main cause is the mixing ratios in the duct. WANG and XU3I usedcombustible gases!-2). These occurrences normally five-order WENO scheme and elementary reactionattribute to leakage of combustible mixture gas in the model to simulate the propagation process of themining or industrial ducts. When mixed with air, such detonation wave for H2-O2 mixture gas in heart-shapedgases react violently. If ignited by some initiation sources, duct, and analyzed the process of wave system evolutiothey form a turbulent flow, and become combustible, and chemical dynamics accompanying the secondaryexplosive and even detonable due to disturbance from initiation. ZHANG et al 4) adopted simplified two-stagebarriers such as equipment and ducts. It is, therefore, chemical reaction model and improved high precisionof great significance to conduct research on propagation space-time conservation method (CE/Se)to simulateprocess of explosive wave produced by combustible deflagration-to-detonation process of combustible gasmixture gas after ignition. This resembles an explosion All these previous numerical simulation studies wereof a non-ideal explosive. In contrast to explosion of performed using single gas and only one material incondensed explosives, such a gas explosion is calculation domain. Up to our knowledge, there is nocharacterized by slowering pressure-rise, longer energy substantial understanding on the explosion characteristicsrelease time and longer over-pressure acting time on of combustible mixture gas and two or more materials instructures/9-10). Due to this fact and unavailability of calculation domain. The need therefore arises to studyanalytical solutions for the explosive wave produced by such situations. With our indigenously developedcombustible mixture gas, the research on explosion of two-dimensional Euler code based on Youngs techniccombustible mixture gas was mainly carried out by for processing multi-material interface and combustionnumerical simulation. In recent years, ORAN et all function model to simulate ignition process,numericalnumerically have simulated the cellular detonation of analyses were performed for the evolution process of theHr-Oz-Ar mixture gas. Their results indicated that the explosive flow field inside and outside the duct whencollision of triple wave points plays a very important role hydrogerne-based combustible mixture gasin the secondary initiation. With the combination ofplod中国煤化工 nations, variousFoundation item: Project(10572026)supported by the National Natural Science FoundatiCNMHGRecelved date: 2008-01-05: Accepted date: 2008-03-24nding author: WANG Cheng, Associate professor, PhD; TeL: +86-10-68912762; E-mail: wangcheng@biteducnJ.Cent. South Univ. Technol. (2008)15: 361-367effects were postulated depending on various(-1(-V)<1