Numerical Surface Flow Visualization

Surface oil flow is an experimental flow visualization technique that depicts the surface flow pattern near the body of the model. Traditionally, a particle tracking technique that generates streamlines near the model body is used to depict surface flows in CFD flow simulations. In this paper, we compared surface flows represented by streamlines with those represented by a texture technique known as Line Integral Convolution (LIC). We found that streamlines used to depict surface flows are discontinuous in general and the quality of the surface flow pattern is highly dependent on the placement of the streamlines. Whereas, the LIC technique clearly depicts surface flows that closely resemble surface oil flows. We also found that surface flows near regions of vortex structures and saddle points are not best shown using the streamline technique compared to the LIC technique. For unsteady flow simulations, we compared streaklines with a new texture synthesis technique called Unsteady Flow Line Integral Convolution (UFLIC) that we have recently developed. UFLIC accurately reveals the dynamic behavior of unsteady surface flows during animation.