The Research Of Real Fluid Simulation Methods

The simulation of nature phenomenon with graphics methods is always an emphasis which is concerned by researchers of the computer graphics field. According to the development process of fluid simulation methods in computer graphics field, the tools of classical geometry such as lines, smooth curves, planes and smooth curving planes, are no longer competent for the description of this complicate phenomenon. Therefore, the researchers turn to new technologies based on physical process. The particle system method and the method based on physical process are two modeling methods which can describe irregular objects, and capture the details of fluid movement. So, they are used in fluid simulation field increasingly.In this dissertation, according to the theory of particle system, we develop the models of fountains and waterfalls after the analysis of their movement traits. In the simulation of fountains, a variety of particle elements are used to produce different effects of fountains, which demonstrate the flexibility of the particle-based method. In order to gain more vivid effect of waterfalls, a small section of waterfall's trajectories is used as the basic particle element. And in the simulating process, the static detection method and the bounding box method are applied to test whether the waterfall has collided with surroundings, which will bring spray splash. Besides, in this dissertation, blend operations are introduced to make the scene look translucent. The results demonstrate that the particle system method is prior in the course of irregular fluid simulating, and the collision theory can add reality to the visual scene.When dealing with general flows, the method based on physical process can reflect more details of fluid movement, and can solve free surface problems. Smoothed particles hydrodynamics is a theory based on N-S equations, which can capture more complex phenomena of fluid movement more expediently and more comprehensively. In the dissertation, the SPH rules discrete the N-S equations, and then a simulation procedure to build a dam-break model is presented. The results demonstrate that this method can identify the free surface, and represent the changes in fine scale, such as spray splashing and integration, free surface deformation , and so on.As is shown in the results, the two methods shown in this dissertation have produced satisfying results, which proved the superiority of methods based-on physical moving rules.