Research Projects: Out-of-Core Flow Field Visualization
Numerical simulations are becoming more and more powerful, simulating physical phenomena at ever increasing resolution. No longer is it possible to visualize the resulting massive data sets using an exclusive in-core approach. The goal is to provide a scientist with intuitive and interactive tools for the exploration and analysis of large time-varying data sets. The challenge is to visualize the data generated by high-precision simulation runs without loss of accuracy. Unfortunately, available computational resources on the visualization side frequently vary drastically from those on the simulation side. This implies that the amount of data has to be reduced to allow for reasonable visualization times.
The goal of the project was to enable visualization of complex scientific data sets while using minimal CPU and memory footprints, enabling the system to run on low-cost commodity hardware as well as massively parallel systems. The out-of-core approach is specialized for real-time visualization of large scale time-varying data sets at the available highest level of resolution and suitable for virtual wind tunnel scenarios. The system was used to implement a volumetric particle injector, which can emit up to 60,000 particles into the flow field while maintaining an interactive frame rate of 60 frames per second. This performance is achieved by pre-calculating a dense uniform rectiliniar grid of particle injectors (N^3 trajectory seeds) and storing the particles on all resulting trajectories out-of-core in a scheme optimized for selection of sub-grids.
Data sets were generated for a classical problem: simulating the flow of a fluid around a spherical object. In our case, a Reynolds number of about 2000 was selected to simulate the flow field around a sphere pushed slowly through water. A rectilinear grid of 128*128*1024 was used for the computation of about 250 time steps. The pictures below show some results.
- Kuester, F., Bruckschen, R., Hamann, B., and Joy, K. I. (2001). Visualization of Particle Traces in Virtual Environments. In Shaw, C. D. and Wang, W., editors, ACM Symposium on Virtual Reality Software and Technology 2001 (VRST 2001), pages 151–157.
- Ralph W. Bruckschen, Falko Kuester, Bernd Hamann, Kenneth I. Joy, Real-Time Out-of-Core Visualization of Particle Traces, in: IEEE 2001 Symposium on Parallel and Large-Data Visualization and Graphics (PVG2001), pages 45--50, 2001.
Related Resarch Projects
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