Validation of a Vortex-Panel Method Software for Full-Scale Flying Wing Aerodynamics

This study presents the validation of FlightStream, a vortex-panel method solver, for the aerodynamic analysis of a flying wing model at full-scale Reynolds number. The validation is conducted using experimental data from NACA Technical Note 1212 (1947), which investigated the influence of a reflex-cambered mean line on the aerodynamic characteristics of a highly tapered, moderately swept-back wing at M = 0.13 and Re = 4.8 million. In this work, the geometry and flow conditions described in the technical report are reconstructed and simulated using different settings for the solver. The validation step is preceded by a grid convergence study, an essential verification step to ensure mesh-independent results while preserving fast simulation times. The features of the flow over the flying wing in the original report (unsteady and highly separated) required the exploration of different solver settings to achieve accurate results. Comparison of lift, drag coefficients resulted in an accuracy of 5% at low and moderate angles of attack. At stall conditions, the solver accuracy is reduced significantly. However, the validation results clearly highlight the adequacy of FlightStream for aerodynamic analysis under certain flow conditions, providing results much faster than full-fidelity CFD solvers.