33th Congress of the International Council of the Aeronautical Sciences

03.1 - Aerodynamics – CFD Methods and Validation


S.-H. Peng, Swedish Defence Research Agency, FOI, Sweden

Hybrid RANS-LES methods exploit the merits of RANS (Reynolds-Averaged Navier-Stokes) and LES (Large Eddy Simulation) modelling approaches, enabling turbulence-resolving simulations with computing resources less demanding than full LES. Based on a set of involved research activities on hybrid RANS-LES modelling approaches, a comprehensive overview about recent development and applications are reported in this work, with primary focus on aerodynamic analysis industry relevance serving aeronautical applications. Along with a progressive maturation in engineering practice of using existing hybrid RANS-LES modelling approaches, new development has been driven by further enhancement of CFD simulation accuracy and improved modelling feasibility. Among others, the RANS-LES interface, which is regarded as a so-called “grey area”, has attracted particular attention in current studies for Grey-Area Mitigation (GAM) in order to enable reasonable LES-resolving capabilities over the interface in the LES region. Some recent effort made to develop the GAM method will be reported. Aerodynamic applications of hybrid RANS-LES method are exampled with unsteady aerodynamic flow simulations, severing aerodynamic analysis, flow control, aero-optic analysis and aero-acoustic analysis. By means of these demonstrated applications, the advantage and current limitations of hybrid RANS-LES methods in relation to further development are discussed.

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