Commutative recursive filters for explicit-filter large-eddy simulation of turbulent flows

A recursive filtering technique is developed to improve the computational efficiency of explicit-filter large-eddy simulation in highly parallelized computational environments. In parallel computations on a partitioned domain, unlike in non-recursive explicit filtering in which the number of ghost cell layers for storing neighbor cell values to ensure communication with neighbor partitions is increased rapidly as the stencil of the filter becomes wider, the present recursive filtering technique requires only a single layer of ghost cells for storing immediate neighbor cell values regardless of the stencil width of the filter. A generalized algorithm for construction of recursive filters with desired filter widths is developed. The computational efficiency of the proposed recursive filtering technique over the conventional non-recursive broad-band filtering techniques in terms of memory usage and computational time is presented. (C) 2021 Elsevier Ltd. All rights reserved.