In this paper, computations of gaseous detonations in several configurations are performed and discussed. The objective is to investigate the detonation characteristics, specially the influence of losses, through a quantitative analysis of the mean hydrodynamic structure. The results are divided into two parts: The first one relates to the propagation of ideal detonations without losses and to their characterization for a specific set of thermodynamic parameters, and the second part investigates the influence of losses on the averaged hydrodynamic structure of detonations. This is achieved by means of a specific and canonical configuration, in which a detonation wave propagates in a reactive layer bounded by an inert gas. This topology is investigated through a comparison of the instantaneous flow-field, cellular structure, and averaged quantities such as the mean curvature and the hydrodynamic thickness. This configuration may be regarded as non-ideal, as the detonation experiences losses due to the expansion of the detonation products toward the inert layer. The prediction of the detonation characteristics, as well as the conditions at which quenching occurs, remains a challenge when losses are involved. The main objective is to assess to what extent the hydrodynamic thickness can be used as a relevant length scale in the analysis of the resulting database. The results also highlight the key features of this configuration, which isolates a specific issue related to the rotating detonation engines. The temperature of the inert layer strongly affects the structure of the detonation–shock combined wave. For a high-temperature inert gas confinement, a detached shock appears in the upper layer and a jet of fresh mixture develops downstream of the front. For this condition, we observed a reduction in the critical dimensions by a factor of two. The degree of regularity of the detonation structure, from weakly unstable to mildly unstable cases, through the variation of the reduced activation energy, was investigated. The hydrodynamic thickness appears to be a useful characteristic length scale for the detonation, as it allows a better analysis of the results and a scaling of data. Moreover, the detonation velocity deficit can be globally expressed as a function of the ratio of the hydrodynamic thickness to the mean radius of curvature at the bottom of the wall.

中文翻译：

---

计算有损失的气态爆轰的平均水动力结构

在本文中，执行和讨论了几种配置中的气体爆炸的计算。目的是通过对平均水动力结构的定量分析来研究爆轰特性，特别是损失的影响。结果分为两部分：第一部分涉及没有损失的理想爆炸的传播及其对一组特定热力学参数的表征，第二部分研究损失对爆炸的平均水动力结构的影响。这是通过特定的规范配置实现的，其中爆震波在以惰性气体为边界的反应层中传播。通过比较瞬时流场、细胞结构、和平均量，例如平均曲率和流体动力学厚度。这种配置可能被认为是不理想的，因为由于爆震产物向惰性层的膨胀，爆震经历了损失。当涉及损失时，爆轰特性以及发生淬火的条件的预测仍然是一个挑战。主要目标是评估水动力厚度在多大程度上可以用作分析结果数据库中的相关长度尺度。结果还突出了这种配置的关键特征，它隔离了与旋转爆震发动机相关的特定问题。惰性层的温度强烈影响爆轰-冲击组合波的结构。对于高温惰性气体限制，在上层出现分离激波，在锋的下游形成一股新鲜的混合物。对于这种情况，我们观察到临界尺寸减少了两倍。研究了爆炸结构的规律程度，从弱不稳定到轻度不稳定，通过降低的活化能的变化。流体动力学厚度似乎是爆炸的有用特征长度尺度，因为它允许更好地分析结果和数据缩放。此外，爆轰速度赤字可以全局表示为流体动力学厚度与壁底部平均曲率半径之比的函数。我们观察到临界尺寸减少了两倍。研究了爆炸结构的规律程度，从弱不稳定到轻度不稳定，通过降低的活化能的变化。流体动力学厚度似乎是爆炸的有用特征长度尺度，因为它允许更好地分析结果和数据缩放。此外，爆轰速度赤字可以全局表示为流体动力学厚度与壁底平均曲率半径之比的函数。我们观察到临界尺寸减少了两倍。研究了爆炸结构的规律程度，从弱不稳定到轻度不稳定，通过降低的活化能的变化。流体动力学厚度似乎是爆炸的有用特征长度尺度，因为它允许更好地分析结果和数据缩放。此外，爆轰速度赤字可以全局表示为流体动力学厚度与壁底部平均曲率半径之比的函数。流体动力学厚度似乎是爆炸的有用特征长度尺度，因为它允许更好地分析结果和数据缩放。此外，爆轰速度赤字可以全局表示为流体动力学厚度与壁底部平均曲率半径之比的函数。流体动力学厚度似乎是爆炸的有用特征长度尺度，因为它允许更好地分析结果和数据缩放。此外，爆轰速度赤字可以全局表示为流体动力学厚度与壁底部平均曲率半径之比的函数。