Graduate School of Science and Engineering
Laboratory of Fluid Mechanics, Prof.Yamaguchi
The perspective of Yamaguchi Lab. is to gain clear understanding for flow characteristics and phenomena of functional fluids (such as magnetic fluid) and supercritical fluids (such as CO2 ), and to develop innovative applications in environmentally friendly energy conversion systems.
- Flow dynamics of magnetic fluid
- Innovative applications for energy conversion systems
- Flow dynamics of supercritical CO2
- Innovative applications for environmentally friendly refrigeration systems
- Complex flow dynamics of non-Newtonian fluids and its application for flow devices
Magnetic fluid is a colloidal suspension system of nano-sized ferro- or ferri-magnetic particles stably dispersed in a carrier (or base) liquid. It is an artificial material rather than formed naturally. It has prominent character of the fluidity and also possesses magnetic properties. Magnetic fluid can be manipulated to position or forced to flow by means of a magnetic force. There are many striking phenomena in the physical behavior of magnetic fluids that are activated by imposing magnetic fields. The overall field of study in magnetic fluid has a highly interdisciplinary character, including physics, chemistry, engineering, mathematics and even medicine in practical applications.
From the viewpoint of keeping earth sustainable and preventing global warming, it is desirable to develop STE (Solar Thermal Energy)-based technologies with using ecologically safe working fluids such as hydrocarbons or carbon dioxide (CO2). CO2 becomes the supercritical state over the critical point in the supercritical CO2, a small change in temperature or pressure can result in a large change in thermal properties, especially in the state close to the critical point. The flow of supercritical fluids has become a hot topic in engineering applications. We investigate the flow mechanism of CO2 with phase change and develop innovative energy conversion devices (i.e. heat pump, refrigeration system, solar Rankin system).
Fluids that exhibit characters not predicted by the Newtonian constitutive equation given in Newton's law of viscosity are non-Newtonian fluids. The exceptions to the Newtonian fluids are not of rare occurrence, and in fact many common fluids are non-Newtonian. Some examples are: paints, solutions of various polymers and molten plastics; food products such as apple sauce, ketchup and other mammalian whole foods; synovial fluid found in joints, blood and other organic fluids; many solid-liquid and liquid-liquid suspensions such as fibers in a liquid paper pulp, coal slurries, emulsions of water in oil or oil in water, and so on. Non-Newtonian fluids are often found in many fields of engineering fluid mechanics, and exhibit interesting, useful and even exciting characteristics differed from those found in Newtonian fluids. Study on flow behavior and development of non-Newtonian fluids in engineering application are actively carrying out in our laboratory.
- Magnetic fluid
- Supercritical CO2
- Non-Newtonian fluid
- Energy conversion
- Sustainable energy