Visualization of CFD simulation data on unstructured, 3D grids poses several challenges. The wide range of real-world data set sizes and the geometric versatility within individual, unstructured CFD simulation models present special challenges to the engineers analyzing flow simulation results. Users also face perceptual problems such as occlusion, visual complexity, lack of directional cues, and lack of depth cues. These perceptual problems combined with the versatility of real-world CFD simulation data models motivates highly interactive and versatile visualization solutions.

We present two new integral objects, the streamrunner and streamcomets, that address these challenges. The streamrunner gives the user interactive control over the evolution of streamlines from the seed point until reaching their full length. The streamrunner control minimizes occlusion and visual complexity and maximizes directional and depth cues for flow visualization in 3D. The streamcomet shifts even more interactive control to the user by letting the user control the position of the comet's head along the integral path, the comet tail length, the diameter of the comet head and tail, and optionally the comet's animation speed. We also propose the use of the streamrunner and streamcomets for unsteady flow visualization. Combined with our other interactive 3D flow visualization tools, these new integral objects represent two further steps in supplying a strong demand for more interactive visualization solutions for CFD simulation data on complex, unstructured grids. results.

Here the streamcomets reflect the flow on the cylinder portion of an intake port data set. The user is afforded a new level of control when investigating fluid flow in 3D with streamcomets.

This is an extreme close up view of the streamcomets on the surface of one of an intake port.

streamcomets showing the flow in the context of a combustion chamber from CFD

streamcomets with "medium" length tails and no context information

small streamcomets with long tails showing the characteristics of 3D flow

streamcomets with "short" tails and context information

small streamcomets seeded with a variable resolution plane

streamcomets showing the flow of air around a cow

streamcomets seeded with a rake

streamcomets seeded with a variable resolution seeding plane

streamcomets showing the flow on a 2D slice through a ring