Broadband noise generated by the turbulent flow around the airframe is one of the most important
components of aircraft generated acoustic nuisances. Its prediction and subsequent reduction is
essential for achieving the ACARE 2020 objectives of noise level reductions. However, the complexity
and diversity of broadband turbulent noise sources makes that prediction with present numerical tools
extremely challenging and far from mature.

VALIANT is an upstream research-oriented project, with objective to tackle this challenge by
generating new experimental data and validating and improving numerical tools for prediction of
airframe noise (AFN) generated from landing gears, slats, flaps and local separation regions. Due to
the extremely complex physical nature of the phenomenon and the high computational cost of
computing full aircraft configurations on one hand, and a lack of a reliable experimental database on
the other hand, VALIANT focuses on key generic test cases representing the major broadband AFN
mechanisms associated with multiple body interactions: two-struts (landing gear), wing-flap, slat-wing
and gap-turbulence. For all these configurations, the components of the noise prediction chain (for
turbulent/source region, near- and far-field propagation domains) and their mutual interactions are
evaluated and avenues of improvement developed.

It is expected that by validating and improving the predictive tools, a deeper insight into the
mechanisms behind AFN will be obtained, which is an essential step towards new efficient AFN
reduction concepts and their optimization to achieve the required breakthrough towards quieter
aircraft.

The consortium is formed by 12 European and Russian partners: 2 universities and 7 research
establishments including the most important technology providers to airframe industry, and 3
companies (2 SME) providing dedicated engineering services and software tools in aeroacoustics to
transport industries with emphasis on aeronautics.

Thilo Knaake thilo.knaake@cfd.tu-berlin.de
Dipl. Ing. Thilo Knaake	FG Numerische Fluiddynamik