A Time-Accurate Inflow Coupling for Zonal LES

TL;DR

This paper presents a tool-chain for accurately transferring instantaneous turbulent inflow data between different flow solvers, enabling high-fidelity, stable zonal LES simulations that preserve flow features and scales.

Contribution

It introduces a novel interpolation-based coupling method that maps arbitrary inflow data into target domains while conserving turbulence structures.

Findings

Stable simulations that replicate source flow features

Effective mapping of arbitrary data distributions

Conservation of turbulent structures and scales

Abstract

Generating turbulent inflow data is a challenging task in zonal Large Eddy Simulation (zLES) and often relies on predefined DNS data to generate synthetic turbulence with the correct statistics. The more accurate, but more involved alternative is to use instantaneous data from a precursor simulation. Using instantaneous data as an inflow condition allows to conduct high fidelity simulations of subdomains of e.g. an aircraft including all non-stationary or rare events. In this paper we introduce a tool-chain that is capable of interchanging highly resolved spatial and temporal data between flow solvers with different discretization schemes. To accomplish this, we use interpolation algorithms suitable for scattered data in order to interpolate spatially. In time we use one-dimensional interpolation schemes for each degree of freedom. The results show that we can get stable simulations that map all flow features from the source data into a new target domain. Thus, the coupling is capable of mapping arbitrary data distributions and formats into a new domain while also recovering and conserving turbulent structures and scales. The necessary time and space resolution requirements can be defined knowing the resolution requirements of the used numerical scheme in the target domain.