Influence of Aerodynamic Shape Parameters on Flight Qualities of Flying Wing Configuration

This study aims to explore how specific aerodynamic shape parameters impact the performance and flight stability of a flying wing design. We began with a modified double-sweep SACCON planform as our foundational geometry, refining it through the Ring Vortex Lattice Method (R-VLM) in conjunction with the Non-dominated Sorting Genetic Algorithm II (NSGA-II). The resulting optimal configuration showcased sweep angles of ۴۳° and ۴۷°, with its transition point situated ۳.۱ m from the root chord. To assess its behavior, we conducted both static and dynamic stability analyses using XFLR۵ and Advanced Aircraft Analysis tools. Furthermore, Computational Fluid Dynamics (CFD) simulations were executed in ANSYS Fluent, employing the SST k-ω turbulence model, to validate the aerodynamic characteristics. Experimental validation took place in a subsonic wind tunnel, utilizing scaled ۳D-printed models, where surface pressure measurements were meticulously gathered via a ۶۴-channel scanner. Our findings reveal that the spanwise position of the sweep exerts a more significant influence on lateral-directional stability than the sweep angle itself. Quantitatively, the optimized design achieved a notable ۲۸% enhancement in aerodynamic efficiency (L/D ratio) and a ۳۶% reduction in roll mode time constant when compared to the initial baseline configuration. Additionally, the optimized model exhibited an average deviation of merely ۴% between CFD predictions and experimental outcomes, thereby confirming the accuracy of our simulations and the efficacy of the optimization methodology. Ultimately, the optimized configuration demonstrated both improved aerodynamic efficiency and enhanced flight stability, underscoring the effectiveness of the proposed methodology.

کلیدواژه ها:

Sweep angle ، Sweep position ، Computational fluid dynamics ، Flying wings ، Lift variations with time