The Karman Vortex in a Medical Imaging Context: A Validated Computational Model of Laminar Shedding

摘要

This paper considers a near wall 3-D computational fluid dynamics model of the Karman Vortex in a cylindrical pipe, but in a medical imaging context, using a commercial finite volume fluids code (CFX 5.3, AEA Technology, Oxford, UK). Convergence was established using standard mesh invariance tests and the results were validated by comparison with data from published texts. However, the near wall conditions complicated comparison with Strouhal and Reynolds number data. Experimental validation was performed by comparing the computational results with fluorescent dye injection flow visualization. The dye patterns revealed a shedding periodicity of 0.84±0.07 seconds, as compared to 0.9 seconds obtained from the computational fluid dynamics. Comparison with a virtual flow visualization from the computed velocity dataset also demonstrated good agreement. Accurate description of the full flow field has implications for medical imaging since it offers a 'calibrated' standard by which the potency of flow-imaging systems may be judged.