Fluid flows in chemical engineering are mainly characterized by the coexistence of turbulent and non-turbulent fluids. Nonetheless, in traditional turbulence models, the laminar portion of the fluid flow is often neglected and constitutive laws are expressed to describe fully turbulent states within computational grids. We perceived this situation is a source of inaccuracies in modeling practical engineering flows. In this work, a stability criterion for turbulent flows, originating from the principle of compromise-in-competition between viscosity and inertia, is used to obtain closure in the turbulence model, which defines the energy-minimization multi-scale (EMMS)-based turbulence model. Analogous to two-phase flow, the model regards single-phase complex flows as a mixture of turbulent and non-turbulent fluids, and the effect of meso-scale eddy structure on the effective coefficient of viscosity is also considered. The EMMS-based turbulence model is tested against three benchmark problems, namely, the lid-driven cavity problem, flow through a conical diffuser, and flow over an airfoil using experimental and direct numerical simulation (DNS) data. Numerical results show that the EMMS-based turbulence model improves the accuracy of turbulence modeling, demonstrating its feasibility and practicality for accurate simulations of engineering complex flows.

化学工程中的流体流动的主要特征是湍流和非湍流并存。尽管如此，在传统的湍流模型中，流体流动的层流部分经常被忽略，本构定律被表达来描述计算网格内的完全湍流状态。我们认为这种情况是对实际工程流程进行建模的不精确之处。在这项工作中，基于粘性与惯性之间的折衷原则，湍流的稳定性判据被用于在湍流模型中获得闭合，该模型定义了基于能量最小化多尺度（EMMS）的模型。湍流模型。与两相流相似，该模型将单相复杂流视为湍流和非湍流的混合物，并考虑了中尺度涡结构对有效粘度系数的影响。使用实验和直接数值模拟（DNS）数据，针对基于EMMS的湍流模型针对三个基准问题进行了测试，即盖驱动空腔问题，流经圆锥形扩散器以及流过机翼的问题。数值结果表明，基于EMMS的湍流模型提高了湍流建模的准确性，证明了其对工程复杂流进行精确模拟的可行性和实用性。