Toward a universal description of multiphase turbulence phenomena based on the vorticity transport equation
Toward a universal description of multiphase turbulence phenomena based on the vorticity transport equation
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基于涡量传递方程的多相湍流现象的通用描述
DOI：
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发表时间：
2022
期刊：
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通讯作者：
S. Schneiderbauer
中科院分区：
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作者：
Mahdi Saeedipour;S. Schneiderbauer
由于多相流在不同尺度上的复杂相间相互作用，了解湍流的演化仍然是一个挑战。本文试图从一个新的角度来揭示多相湍流现象，利用经典的涡量概念及其在湍流能量级联演化中的作用。我们从两种不同的多相流公式，这是一个流体和两个流体模型的涡量输运方程。通过将衰减均匀各向同性湍流（HIT）问题扩展到多相流背景下，我们在（i）薄界面层和（ii）均匀分布的固体颗粒的存在下进行了两次高分辨率的HIT模拟。这两种配置允许界面湍流和颗粒湍流的调查，分别。除了在这两种情况下的全球流动特性的分析，我们评估的频谱贡献的涡度输送方程中的每个生产/耗散机制的涡度能量（拟能）的分布跨越的尺度。我们的讨论的基础上的主要相间相互作用机制在涡量传输（即界面湍流的表面张力和颗粒湍流的阻力）的作用，并揭示了类似的贡献，从这些机制的多相湍流级联。结果还解释了多相HIT问题的动能谱和拟能谱与其单相相似性的偏差，证实了该方法建立多相湍流通用描述的有效性。
Understanding the evolution of turbulence in multiphase flows remains achallenge due to the complex inter-phase interactions at different scales. This paper attempts to enlighten the multiphase turbulence phenomenon from a new perspective by exploiting the classical concept of vorticity and its role in the evolution of the turbulent energy cascade. We start with the vorticity transport equations for two different multiphase flow formulations, which are one-fluid and two-fluid models. By extending the decaying homogeneous isotropic turbulence (HIT) problem to the multiphase flow context, we performed two highly-resolved simulations of HIT in the presence of (i) a thin interface layer, and (ii) homogeneously distributed solid particle. These two configurations allow for the investigation of interfacial turbulence and particulate turbulence, respectively. Besides the analysis of the global flow characteristic in both cases, we evaluate the spectral contribution of each production/dissipation mechanism in the vorticity transport equation to the distribution of vortical energy (enstrophy) across the scales. We base our discussion on the role of the main inter-phase interaction mechanisms in vorticity transport (i.e. the surface tension for interfacial turbulence and drag force for particulate turbulence), and unveil a similar contribution from these mechanisms to the multiphase turbulence cascade. The results also explain the deviation of kinetic energy and enstrophy spectra of multiphase HIT problems from their single-phase similitudes, confirming the validity of this approach for establishing a universal description of multiphase turbulence.