Real time simulation of a tornado

1. Real time simulation of a tornado Shiguang Liu, Zhangye Wang, Zheng Gong, Lei Huang, and QunshengPeng

2. Abstract • simulating a tornado scene • Based on Reynold-average Navier-Stokes equations. • The dust particle flow is modeled by non-viscosity Navier–Stokes equations • Multi-Fluid Solver is designed and implemented on GPU. • Efficient method is proposed to simulate the tornado’s interaction with surrounding large objects.

3. Introduction • RATFM is proposed to simulate the chaos appearance of tornados more realistically than previous methods • A novel two-fluid system solver is designed to achieve real time simulation • To our knowledge, it is the first attempt to simulate damage from a tornado on surrounding objects • Our system is easy to implement. By inputting different initial parameters, different tornado scenes can be produced automatically

4. Related Work • simulating natural phenomena • smoke,water & fire • semi-Lagrangianmethod • Mizuno • volcanic clouds consist of two fluids • Müller et al. • smoothed particle hydrodynamics • Losasso et al. • particle level set method • simulate the interactions among multiple liquids • Zhu et al. • two-fluid lattice Boltzmann model

5. Related Work • Modeling the motion of dust particles • contact force, normal force, and shear force • Ding et al. • propose an approach for tornado simulation • To use many particles (not real time) • Our • TFM method • Real-time • interaction with large objects

6. Reynold-average Navier–Stokes equations

7. Interaction force • Between air flow and dust particle flow • plays an important part in modeling a tornado

8. Reynolds shear stress

9. Reynold-average two-fluid model • dust particle flow model • non-viscosity, incompressible fluid

10. Boundary conditions

11. tornado’s conditions • horizontal velocity field : rotating • vertical velocity field : uplifting

12. Modeling contrast between RATFM and TFM (results) RATFM TFM

13. The tornado’s interaction with large objects • Tonado에 의해 부서지는 object를 시뮬레이션 • Object 는 voxel에 연결 되어 있음 • Voxcel이큰 압력을 받으면 연결된 object 부분을 부숨

14. The tornado’s interaction with large objects • Object가 받는 힘 • Torque

15. The tornado’s interaction with large objects

16. The tornado’s interaction with large objects (results)

17. The tornado’s interaction with large objects (results)

18. The tornado’s interaction with large objects (results)

19. Multi-Fluid Solver on GPU • Our model describes a multiple fluid system • Air flow • particle flows. • We solve the multiple Navier-Stokes equations in parallel in one rendering pass by combining multiple field data texture into one texture. • It reduces the calculating time • Flat 3D texture technique • It’s easy to read and store velocity data

20. Multi-Fluid Solver on GPU • Flow chart of Multi-Fluid Solver • With this, we can solve multiple NS in parallel in one rendering pass.

21. Multi-Fluid Solver on GPU (results)

22. Results and Discussion • Successfully generated dynamic tornado scenes • Calculating the Poisson equation • use the Jacobi iterative method • 25 frames per second • Moreiterations, lower frame rate

23. Conclusion and Future Works • Simulating realistic tornado scenes • To use RATFM • The tornado’s interaction with surrounding large objects was simulated • Future Works • mixtures with three or more fluid components • Water & Oil • Other phenomena