Particuology ( IF 3.5 ) Pub Date : 2018-06-25 , DOI: 10.1016/j.partic.2018.01.008 Paul Kieckhefen , Thomas Lichtenegger , Swantje Pietsch , Stefan Pirker , Stefan Heinrich
Although numerical models such as the computational fluid dynamics–discrete element method (CFD–DEM) have enabled the accurate simulation of laboratory-scale apparatuses, the application of these methods to large-scale apparatuses with many particles and time scales ranging from minutes to hours remains a challenge. The recently developed recurrence CFD (rCFD) method seeks to overcome these issues in pseudo-periodic processes by extrapolating globally recurring patterns in a physically meaningful way and describing the transport and interaction of passive scalars using Lagrangian tracers. Spouted beds represent an interesting target because of the associated variety of flow regimes. They can be effectively described by CFD–DEM on the time scale of tens of seconds, whereas industrially relevant processes typically take hours. In this contribution, we established the validity of applying the Lagrangian rCFD method to spouted beds by demonstrating the accurate reproduction of the particle residence time distribution in a fictitious spray zone. The deposition of spray droplets onto tracer particles was simulated for 1 h, and the particle surface coverage distribution was estimated using a statistical approach for both an unstabilized prismatic spouted bed and one stabilized by draft plates.
中文翻译:
使用递归CFD模拟喷射床中的喷涂层
尽管诸如计算流体动力学离散元方法(CFD–DEM)之类的数值模型已经能够对实验室规模的设备进行精确的模拟,但是这些方法在具有许多颗粒且时间范围从几分钟到几小时不等的大型设备中的应用仍然是一个挑战。最近开发的递归CFD(rCFD)方法试图通过以物理上有意义的方式推断全局重复模式并使用拉格朗日示踪剂描述无源标量的传输和相互作用来克服伪周期过程中的这些问题。喷动床代表着一个有趣的目标,因为相关的流动方式多种多样。CFD–DEM可以在数十秒的时间范围内有效地描述它们,而与工业相关的过程通常要花费数小时。在这笔捐款中,我们通过证明在假想的喷雾区域中颗粒停留时间分布的精确再现,确立了将Lagrangian rCFD方法应用于喷动床的有效性。模拟喷雾液滴在示踪剂颗粒上的沉积1小时,并使用统计方法估算未稳定的棱柱形喷头床和通过通风板稳定的颗粒表面覆盖率分布。