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目前多数两相流动的大涡模拟采用单相流动的亚网格尺度应力模型,没有考虑或者没有完整地考虑两相亚网格尺度应力间的相互作用。本文提出一种两相亚网格尺度动能模型(LES-kkp),可以完整地考虑其相互作用。将该模型用于突扩气粒两相流动的大涡模拟,同时进行统一二阶矩(USM)两相湍流模型的雷诺平均模拟(RANS)。瞬态结果显示出两相流动中的气体形成了典型的拟序结构,但颗粒流动结构完全不同于气体的,没有形成涡结构。LES-kkp和RANS-USM模拟结果实验检验表明,对时间平均速度两种模拟给出结果与实验结果吻合良好,即RANS-USM得到了LES-kkp的验证。对两相均方根脉动速度和两相脉动速度关联量,LES-k-kp的模拟结果优于RANS-USM的模拟结果。
Most current large-eddy simulation of two-phase flow adopts single-phase flow in sub-grid scale stress model, and does not consider or does not completely consider the interaction between two-phase sub-grid scale stress. In this paper, a two-phase sub-grid scale kinetic energy model (LES-kkp) is proposed, which can fully consider its interaction. The model is applied to the large eddy simulation of gas-particle two-phase flow and the Reynolds averaged simulation (RANS) of the unified second-order phase (USM) two-phase turbulence model. The transient results show that the gas in the two-phase flow forms a typical ordered structure, but the particle flow structure is completely different from the gas and no vortex structure is formed. The experimental results of LES-kkp and RANS-USM simulation results show that the two simulations of time average velocity give good agreement with the experimental results, ie, RANS-USM is validated by LES-kkp. The simulation results of LES-k-kp are superior to the simulation results of RANS-USM for the correlation between two-phase root-mean-square pulsation velocity and two-phase pulsatile velocity.