The deformation and dynamics of a single droplet in isotropic turbulence is studied using a Lattice Boltzmann diffuse interface model involving exact boundary flow conditions [1] to allow for the creation of an external turbulent flow. We focus on a small, sub-Kolmogorov droplet, whose scale is much smaller than the Kolmogorov length scale of the turbulent flow. The external flow field is obtained via pseudo-spectral simulation data describing the trajectory of a passive tracer in isotropic turbulence. In this way we combine the microscopic scale of the droplet and the macroscopic scale of the turbulent flow. The results obtained from this fully resolved model are compared to previous studies on sub-Kolmogorov droplet dynamics in isotropic turbulent flows [2], where an analytical model [3], which assumes the droplet shape to be an ellipsoid at all times, is used to describe the droplet deformation. Our findings confirm, that the hybrid pseudo-spectral Lattice Boltzmann algorithm is able to study droplet deformation and breakup in a regime well beyond the ellipsoidal approximation.

使用包含精确边界流条件[1]的Lattice Boltzmann扩散界面模型研究了各向同性湍流中单个液滴的变形和动力学[1]，以允许创建外部湍流。我们关注于一个小的亚科莫哥罗夫小液滴，其尺度远小于湍流的科莫哥罗夫长度尺度。外部流场是通过伪光谱仿真数据获得的，该数据描述了各向同性湍流中被动示踪剂的轨迹。通过这种方式，我们将液滴的微观尺度和湍流的宏观尺度结合在一起。从这个完全解析的模型获得的结果与先前关于各向同性湍流中亚-柯尔莫哥洛夫液滴动力学的研究[2]进行了比较，其中分析模型[3] 假设液滴形状始终为椭圆形，它用于描述液滴变形。我们的研究结果证实，混合伪谱Lattice Boltzmann算法能够研究远远超出椭圆近似的状态下的液滴变形和破裂。