{'fraction_non_alphanumeric': 0.02220726783310902, 'fraction_numerical': 0.010767160161507403, 'mean_word_length': 5.437229437229437, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Grid-independent large-eddy simulation of compressible turbulent flows using explicit filtering

The governing equations for large-eddy simulation (LES) are derived from the application of a low-pass filter to the Navier-Stokes equations. It is often assumed that discrete operations performed on a particular grid act as an implicit filter, causing simulation results to be sensitive to the mesh resolution. Alternatively, explicit filtering separates the filtering operations from discretization operations, and hence alleviates the grid sensitivities. Obtaining a grid-independent LES solution in incompressible flow has been successfully demonstrated by Bose, Moin & You [Phys. Fluids, 22, 105103, 2010]. In the present study, we investigate the use of explicit filtering in obtaining a grid-independent LES solution for compressible turbulent flow. The convergence of simulations using a fixed filter width with varying mesh resolutions to a true large-eddy simulation solution is analyzed for compressible turbulent flow through a channel with periodic constrictions at a bulk Reynolds number of 10 and Mach number of 0.6. The mean and turbulent statistics obtained by the conventional implicitly filtered LES and by the present explicitly filtered LES are compared at two different mesh resolutions. Although grid independence is not fully achieved, this is the first application of explicitly filtered LES to the compressible governing equations and to a quasi-complex geometry.