Continuum models of two-phase flow have been employed to investigate a wide variety of physical phenomena, ranging from bubbly-gas and solid-loaded liquid flows to detonation waves in granular explosives. The set of governing equations consists of mass, momentum and energy balance for each phase, and an equation for the evolution of volume fraction of either phase. The set is closed by providing an equation of state for each phase and by specifying the inter-phase interaction terms. Examination of the time scales associated with the interaction terms shows that in many regions of the flow, the pressures and velocities equilibrate rapidly, which has led to the development of a single-pressure and single-velocity reduced, 5-equation model. Such a reduction is incomplete in that it omits thin shock-like regions (inner layers) where $O\left(1\right)$ pressure and velocity changes can remain. To regularise the reduced model, a number of studies have added dissipative terms which smoothen and thereby resolve these thin shock-like regions. However, the sensitivity of the solution to the choice of regularisation has not been investigated. Further, although the 5-equation model has been used extensively in the literature for numerical computations, its regularisation is often left to the numerical method employed. This study carries out a systematic analysis of the structure of this thin shock-like inner layer, with emphasis on the dependence of the structure of the layer and of the jumps across it on system parameters. The results are compared with those obtained via computations with the parent, 7-equation model.

两相流的连续介质模型已被用于研究各种各样的物理现象，从气泡气体和固体负载液体流到颗粒炸药中的爆震波。控制方程组包括每一相的质量、动量和能量平衡，以及每一相体积分数演变的方程。通过为每个相提供状态方程并指定相间相互作用项来封闭该集合。对与相互作用项相关的时间尺度的检查表明，在流动的许多区域，压力和速度迅速平衡，这导致了单压力和单速度降低的 5 方程模型的发展。这种减少是不完整的，因为它省略了薄的冲击状区域（内层），其中$哦\left(1\right)$压力和速度变化可以保持。为了规范简化的模型，许多研究添加了耗散项，这些项可以平滑并从而解决这些类似激波的薄区域。然而，尚未研究解决方案对正则化选择的敏感性。此外，尽管 5 方程模型已在文献中广泛用于数值计算，但其正则化通常留给所采用的数值方法。本研究对这种类似激波的薄内层的结构进行了系统分析，重点是该层的结构和跨越它的跳跃对系统参数的依赖性。将结果与通过父 7 方程模型计算获得的结果进行比较。