Uncertainty quantification of the flow predictions around the NATO STO AVT-251 unmanned combat aerial vehicle

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 flow predictions (shock wave locations, vortex breakdown, etc.). 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, will be used to establish the robustness of the AVT-251 design and its performance metrics considering uncertain predictions of the dominant flow features. The benefits of this work will also extend to the structural design, whereby appropriate factors of safety can be integrated in the process.