Computational analysis of planar wings designed for optimum span-load

OpenFOAM;Pointwise;Flow transition;Wings;Span-load;Computational fluid dynamics (CFD)

Ranjan, Prateek ; Ansell ; Phillip J.

关键词: OpenFOAM;    Pointwise;    Flow transition;    Wings;    Span-load;    Computational fluid dynamics (CFD);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/92983/RANJAN-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

A computational analysis of three span-optimized wings was conducted using an open-source CFD tool. Simulations were carried out at Rec = 450; 000 in a semi-spherical domain consisting of unstructured tetrahedra close to the wing surface and pyramids in the farfield region. Simulations were carried out in both steady state and semi-transient states to predict ow transition. A comparative study of different turbulence models revealed k-omega-SST and k - kL-omega to be the most suitable turbulence models for this study. The model accuracy was determined using validations with experimental data from a previous study. The required accuracy was achieved using the most appropriate mesh resolution for all three wing designs and second order discretization schemes. Computational results indicated different drag characteristics between the three span-load optimized wings at the design CL. The Viscous Optimized Wing produced the minimum drag while the Elliptic Wing produced the largest drag at design CL. The Inviscid Optimized Wing had the largest aspect ratio but still produced lesser drag when compared to the Elliptical Wing. Surface ow visualization indicated different ow transition characteristics for the three wings. These differences were attributed to the twist distributions specific to each wing. The Inviscid Optimized wing was observed to have largest laminar boundary-layer region at design angle of attack. Qualitative wake analysis indicated different wake characteristics for each wing, attributed to the different span-loads. The Elliptic Wing had the most aggressive wake roll-up. Much lesser wake roll-up was observed for the Inviscid and Viscous Optimized Wings. The largest wake cross-section was observed for the Elliptic Wing, while the smallest wake cross-section was observed for the Inviscid Optimized Wing.