Abstract: With a third-order upwind TVD and Strang-splitting operator splitting method，two-dimensional numerical calculations of detonation combustion with the mixture of H2/O₂/Ar was carried out，in order to study the effects of diluted gases Ar on the propagation of detonation from the straight tube to the branch tube and in the straight tube. The results show that under the four component ratios at 298K，6670Pa initial conditions，the downstream of main detonation tube will produce different degrees of decoupling because of the effects of rarefaction wave，but plane detonation will regain through the wall Mach reflection. When the volume ratio of H2/O₂/Ar is 2:1:7，the detonation wave is diffracted into the branch tube and decoupled into deflagration flame wave. Under the conditions of volume ratio of 2:1:0，2:1:0 and 2:1:1，the detonation wave of level tube is diffracted into the vertical tube，self-sustaining detonation wave will be regained from decoupling detonation wave to the secondary ignition by the several times of wall Mach reflection.

Key words: Detonation；Branch tube；Diffraction；Secondary detonation；Argon

摘要： 为了研究稀释气体Ar的浓度对爆震波从直管往分叉管绕射传播和对直管中爆震波传播的影响，采用三阶TVD迎风格式和Strang-splitting算子分裂法，对H2/O₂/Ar混合物爆震燃烧进行了二维数值计算。计算结果表明:在298K，6670Pa初始条件下，四种组分比条件下，主爆震管下游由于分叉管绕射稀疏波的影响，都会产生不同程度的解耦，但是通过壁面马赫反射后，都能恢复平面爆震；在H2/O₂/Ar体积比为2:1:7时，爆震波绕射进入分叉管后，爆震波解耦成爆燃火焰波；体积比为2:1:0，2:1:1和2:1:4条件下，水平爆震管中的爆震波，绕射进入垂直分叉管后，通过不同次数壁面马赫反射，能够二次起爆，解耦的爆震波恢复成为平面自持爆震波。

关键词: 爆震；分叉管；绕射；二次起爆；氩气