Direct numerical simulation of shock wavy-wall interaction: analysis of cellular shock structures and flow patterns

Abstract

International audienc

Spontaneous singularity formation in converging cylindrical shock waves

“…After substitution into (10), the system decomposes into a set of subsystems, each corresponding with an index l in (12). The leading-order subsystem corresponds to the leading-order coefficient of (12), l = 0, and in that subsystem, all the infinite Cauchy products have been truncated to finite sums.…”

“…Spontaneous triple-point formation also occurs in planar shocks [10][11][12] and detonation waves [13]. Analysis using GSD indicates that this is associated with the development of a singularity [14] characterized by loss of analyticity in the shock geometry as determined via a Fourier treatment.…”

Numerical study of the slip line instabilities in shock-wavywall reflection

“…Clavin等人 [7,8] 为了研究强激波受扰动之后的动力 学行为, 建立了弱非线性激波动力学模型 [8] , 解释了前 人实验 [9] 与数值模拟 [10] 中观测到的三波点的自发形成 机理. 在该模型的推动下, 后续的研究以激波在正弦型 波纹壁反射(图1)为例, 进行了相关实验 [11,12] 和直接数 值模拟 [13,14] 研究, 揭示了在波纹壁反射后, 激波的运 动特征, 并与理论模型 的区别. 已有的实验 [11,12] 研究的是入射波马赫数1.5的…”

“…条件, 左边界为无滑移波形壁, 规则的壁面外形可以 [12,13] . 我们将其横向速度u T , 以及 三波点结构中的反射波与流向所成的角度β n (图4), 在 反射后50 µs时与实验 [12] 结果作了定量对比.…”

Bifurcation of pulsation instability in one-dimensional H2−O2 detonation with detailed reaction mechanism

“…A detonation wave manifested pulsations in one dimension [1] and cellular instability in multiple dimensions [2][3][4][5], depending on the initial conditions and mixture properties. For pulsating detonation near Chapman-Jouguet (C-J) state, extensive experiments and theoretical analyses have observed longitudinal oscillation of the detonation front [6][7][8][9][10][11].…”