Aerodynamic and aeroelastic uncertainty quantification of NATO STO AVT-251 unmanned combat aerial vehicle

Abstract

Turbulence models based on Reynolds-averaged Navier-Stokes (RANS) equations remain the workhorse in the computation of high Reynolds-number wall-bounded flows. While these methods have been deployed to design the configuration developed within the NATO STO AVT-251 Task Group, their deficiencies in modelling complex flows are well-documented. However, an understanding of the sources of errors and uncertainties in RANS solvers, arising for example from different numerical schemes and flow modelling techniques, is missing to date. The aim of this work is to establish and quantify the impact that epistemic uncertainties within RANS solvers have on the aerodynamic and aeroelastic response of the combat aerial vehicle. This will produce a range of all possible values of interest due to the inherent uncertainty of RANS solvers, which is expected to be highly dependent on the flow conditions and geometry configuration. This information, in turn, is used to establish the robustness of the AVT-251 design and its performance metrics considering a high-g pull-up manoeuvre used for structural sizing. It is found that the static aeroelastic analysis without aerodynamic uncertainty (deterministic analysis) under predicted the largest generalised force, with an immediate consequence on the structural design.