沙漠蝗虫飞行尾流的层析粒子成像测速研究:瞬态体积组合揭示隐藏的漩涡单元和快速尾流变形
Aerodynamic structures generated by animals in flight are unstable and complex. Recent progressin quantitative flow visualization has advanced our understanding of animalaerodynamics, but measurements have hitherto been limited to flow velocities at a planethrough the wake. We applied an emergent, high-speed, volumetric fluid imaging technique(tomographic particle image velocimetry) to examine segments of the wake of desert locusts,capturing fully three-dimensional instantaneous flow fields. We used those flow fields tocharacterize the aerodynamic footprint in unprecedented detail and revealed previouslyunseen wake elements that would have gone undetected by two-dimensional or stereoimagingtechnology. Vortex iso-surface topographies show the spatio-temporal signature ofaerodynamic force generation manifest in the wake of locusts, and expose the extent towhich animal wakes can deform, potentially leading to unreliable calculations of lift andthrust when using conventional diagnostic methods.We discuss implications for experimentaldesign and analysis as volumetric flow imaging becomes more widespread.