LES validation on near-field wingtip vortex evolution with wind tunnel characterization at low Reynolds number

• Introduces a cost-effective perspective upright correction (PUC) method to capture vortices using a single tilted camera. • Demonstrates the superior accuracy of PUC method compared to upright camera view, highlighting its novelty in vortex capture. • Validates LES framework in predicting vortex behavior via qualitative and quantitative comparisons with PUC-corrected data. • Showcases LES ability to capture detailed vortex dynamics, including axial velocity, vorticity, and circulation strength. • Examine vortex core properties, revealing that larger wake spiral loci do not necessarily indicate a larger vortex core size. Wind tunnel tests are commonly used to visualize the trailing vortices, but tests involving advanced optical measurement techniques can be costly. Camera-based experiments are more affordable, but the low visibility caused by smoke particles and limitations of the upright view make vortex characterization and quantification challenging. In this paper, the proposed perspective upright correction allows adjustment of the slanted plane during post-processing. This technique has reduced the complexity of wind tunnel set-up, and yet yielding a more accurate result than the native upright view. Large Eddy Simulation (LES) is then utilized with proper mesh design within the vortex core volume to effectively capture the smaller scales features of the wingtip vortex and validate against the perspective upright corrected characterization from wind tunnel experiment. The vortex core defined by its maximum tangential velocity will be analyzed against the physical wake evolution captured in wind tunnel, providing insights into the relationship between these two methodologies. The demonstrated accuracy and credibility of the CFD model can ensure that the future simulations in the extended field can be accurately predicted and analyzed.