Research Of Liquid-Gas Multiphase Model

With the development of computer technology,fluid simulation is an important branch of computer graphics in scientific research and engineering practice,which has been widely used in lots of areas,such as the film and television special effects,military simulation,animation and medical and so on.It is meaningful to acquire a way how to simulate real fluid more rapidly and effectively.Chapter 1 introduces introduction to fluid simulation,including fluid simulation development and significance of main contents of fluid simulation,research situation and development trends and problems of fluid simulation technology.Chapter 2 mainly introduces fluid simulation methods and tools;surface tracking and reconstruction methods;GPU acceleration of relevant content and POV-Ray.Chapter 3 is liquid-gas two phase flow based on SPH method simulation.The problem in the multiphase flow SPH method is: when the medium density is greater than 10,the calculated density is unstable or divergent;when the density ratio is less than 10,relative movement between media is not clear.Buoyancy correction,damping correction and density correction are given in this thesis,and correction of,which insure better simulation of fast-moving bubbles in the water.Chapter 4 realizes the simulation of water boiling.The simulation of water boiling usually has 2 problems: the simulation only focused on bubbles and water,ignoring the simulation of water vapor;and only considered the interaction between bubble motion and water,ignoring the circular movement caused water temperature change.To dealing with these two problems,this thesis gives a new method of the combination of grid method and particle method: using the multiphase flow SPH method to simulate water and air bubbles,and the semi-Lagrangian method to simulate water vapor;at the same time,using real-time data transmission to realize the synchronous simulation of water,bubbles and water vapor.In addition,this method joins the force due to thermal conduction of water and realizes the movement of the water due to changes of water temperature,which making the results more close to reality.Chapter 5 gives a summary of this thesis and some thinking and outlook of the future research of fluid simulation.