Evolving time surfaces in a virtual stirred tank

Abstract

The complexity of large scale computational fluid dynamic simulations demand powerful tools to investigate the numerical results. Time surfaces are the natural higher-dimensional extension of time lines, the evolution of a seed line of particles in the flow of a vector field. Adaptive refinement of the evolving surface is mandatory for high quality under reasonable computation times. In contrast to the lower-dimensional time line, there is a new set of refinement criteria that may trigger the refinement of a triangular initial surface, such as based on triangle degeneracy, triangle area, surface curvature etc. In this article we describe the computation of time surfaces for initially spherical surfaces. The evolution of such virtual “bubbles” supports analysis of the mixing quality in a stirred tank CFD simulation. We discuss the performance of various possible refinement algorithms, how to interface alternative software solutions and how to effectively deliver the research to the end-users, involving specially designed hardware representing the algorithmic parameters.