11.动域-副本1.ppt

Welcome to the Moving Zones lecture. The purpose of this lecture is to introduce new Fluent users to the capabilities of the solver for modeling moving domains. Due to the limited length of this presentation, we will only be able to provide a brief overview of this topic. However, additional material is provided in the Appendix as well as in the Fluent User’s Guide. The presentation is divided into topic areas as shown in this slide. After a brief introduction, we will cover the five modeling approaches for moving domains, progressing from the simplest approach (the Single Reference Frame model) to the most complex (the Dynamic Mesh approach). Again, the goal is to introduce the new user to these topics and provide some guidance about their setup and use. Computational fluid dynamics (or CFD) has been used to examine problems involving moving domains ever since the advent of computer simulation in the 1960s. The motions can either be: Translational – such as the cyclic oscillation of liquid in a tank or a train moving through a tunnel. Or Rotational – which is perhaps the most common. Examples include flows though turbomachines (pumps, turbines, compressors, and related equipment), electric motors, spinning objects such as car tires, and so forth. There are two basic approaches to modeling flows in moving domains. The first approach involves referring the problem to a moving reference frame. For example, we can define a reference frame which is spinning in concert with a rotating tank. The flow is described with respect to the spinning reference frame. However, the fact that the reference frame itself is moving gives rise to “non-inertial” effects – that is, the equations of motion now have additional acceleration terms added to them to account for the moving frame (more about that later). The benefit of using a moving reference frame is often a problem which is inherently unsteady in the stationary frame becomes steady-state in the moving frame of