Comparison of results from turbulence models for the Nomad flaperon-configured aerofoil

Abstract

Incidents involving low speed flutter of the wing-flaperon configured Government Aircraft Factories Nomad N22 and N24 have been reported. Wind tunnel experiments are unable to reproduce the effect. To better understand what could have caused the reported flutter, a computational fluid dynamics based investigation was undertaken, employing a complex commercial simulation software, with the aim to study the local flowfield structures around this configuration, focusing specifically on turbulence effects. Inviscid and viscous flows incorporating the Spalart--Allmaras and RNG $k$-$\epsilon$ turbulence models were computed. Comparisons with experimental data showed excellent agreement among the results, with the predicted section lift coefficients being within 10% of the measured values.