Unsteady Vortex Formation of Low-Aspect-Ratio, Bio-Inspired Propulsors
This is one of the coolest seminars of this term. Professor Matthew had shown us a lot of the top technical in the bio-inspired propulsors. One of the most important theory of his project is the vortices dynamics analysis. This is a very complex problem so that professor had shown us some simple samples for us to understand this vortex analysis. But unfortunately, I really have no idea about this vortex dynamics analysis before. Even professor thought these samples are simple, it is still hard for me to understand.
After seminar, I have read some materials and books about the vortex dynamics. But this is really a hard task to understand it. Until now, I just know just very simple part of it. Here is my introduction for vortices dynamics. Vortices are a special form of existence fluid movement originating in the rotation of the fluid elements. The intuitive images of these organized structures range of from hurricanes to tornadoes, from the aircraft wake vortices to swirling flow in turbines and various industrial plants. One can say that a vortex is a connected fluid region with a high concentration of vorticity compared to its surroundings.
Actually, vortices analysis is very important. Once formed, vortices occupy only very small part in a river, but play an important role in organizing the flow, as "the tendons and muscles of fluid motion '. Vertebrae are also" the voice of the fluid motion ", because at low Mach numbers it is the only source of aeroacoustic sound and noise are. These identifications imply the critical importance of vorticity and swirl throughout the fluid mechanics. 'generation, movement, evolution, instability and collapse of the vorticity and vortices, and the interaction between vortices and solids, between several vertebrae and between vertebrae and other forms of fluid motion, are all the subject of vorticity and vortex dynamics.
So what is the difference between the solid and the liquid and what effect do the vortices in liquid do to
