Modeling and Visualization of Combustion Using Fluid Simulator and Particle Systems Ing. Marek Gayer (supervised by prof. Pavel Slavík) Computer Graphics Group Department of Computer Science and Engineering Faculty of Electrical Engineering of CTU in Prague Czech Republic Student EEICT 2003 conference, Brno, 29 May

2EEICT 2003 Introduction and motivation to coal combustion visualization Both for the ecological and economical reasons) Finding optimal boiler configurations. –To reduce pollution –To find a way for optimal fuel preparation How can visualization help

3EEICT 2003 The modeling of fluid flow - CFD Most often: solving complex differential equations (e.g. Navier-Stokes) Fluid simulators for computer graphics (e.g. ACM Siggraph Proceedings) Coal combustion as an CFD application Current solutions and systems: Precise, robust, well-known Slow, no real-time + -

4EEICT 2003 Our fluid simulator Dividing the boiler area to “voxel” arrays Mass fluxes and velocity changes per time dt based on Newton’s second law and continuity equation Principle of local simulation Is fast, easy to implement, but “unstable”

5EEICT 2003 Virtual coal particle system Used both for simulation and visualization of the combustion process Virtual particle system approach Movement determination: –Aerodynamic resistance –Gravity force

6EEICT 2003 t = 0 seconds: T = 343 o C (above ignition) O 2 concentration = 25% Coal particle Partially burned particle C C C t = 0.01 seconds: T = 345 o C (increased) O2 concentration = 24% Partially burned coal particles Coal particle transformed to burned ash particle C B C C C Interaction of virtual coal particles

7EEICT 2003 Results comparison – numerical approach Built-in numerical comparison code Statistically compares the results between our system and FLUENT From 60% to 80% voxels are less than 20% different from FLUENT values (temperature, flow directions,... )

8EEICT 2003 Sample visualization of volume characteristics

9EEICT 2003 Sample visualization of particle characteristics (particle tracks)

10EEICT 2003 Our interactive combustion system

11EEICT 2003 Conclusion and future research Interactive 2D coal combustion system with: –Fast & simple real-time fluid simulator (reusable) –Simplified combustion engine –Real-time visualization using OpenGL –Results reliability tested with FLUENT –Designated for education and “preview” design Future research: –Precision improvements – further to reality –Further testing on real boiler tasks –The real-time 3D combustion system experiment

12EEICT 2003 Thank you for your attention. ?????? Do you have any questions ?