Taylor-Couette flow in a virtual rheoscopic fluid

Abstract

Physics-based flow visualization techniques seek to mimic laboratory flow visualization methods with virtual analogues. In this work we present the rendering of a virtual rheoscopic fluid (VRF) to produce images with results strikingly similar to laboratory experiments with real-world rheoscopic fluids using products such as Kalliroscope. Our initial work studies flow between concentric rotating cylinders, a classic problem in fluid mechanics. This visualization shows a typical Taylor-Couette flow: above certain critical parameter values, the purely azimuthal flow becomes unstable and a stack of toroidal Taylor vortices forms in the flow. Our virtual rheoscopic fluid is produced by defining a closed-form formula for the orientation of shear layers in the flow and using this orientation to volume render the flow as a material with anisotropic reflectance and transparency. Our algorithm is implemented within VisIt, broadening the data formats to which this work can be applied.