The Takahashi laboratory is divided into two groups of wind group and Leo group according to the nature of the fluid. Each group is divided according to the research subject.
- Wind Team ： Research on fluid related vibration for Newtonian fluid such as water and air.
- Rheology Team ： Research on rheology (complex fluid) for non-Newtonian fluid such as surfactant, liquid crystal, polymer solution.
About the wind group
Research background
We are studying the flow induced vibration in the flow in the wind group. Flow induced vibration is vibration phenomenon caused by fluid flow. In the wind group, we study the flow induced vibration caused by the flow of "air" and "water". Flow induced vibrations occur in structures such as fluids, transportation equipment, equipment such as boilers, heat exchangers, fluid machinery, piping etc... Flow induced vibrations may occur in every place. Flow induced vibrations may cause serious damage if they are released, which is extremely dangerous.
Karman vortex excitation
Karman vortex excitation is a main example of flow induced vibrations. Karman vortex excitation is the vibration phenomenon by the Karman vortex. Karman vortex is a periodic staggered vortex that occurs in the wake of the object placed in the flow as shown in the above figure. The outflow frequency (occurrence frequency of Karman vortex) of this vortex becomes high in proportional to the flow velocity, and inversely proportional to the size of the object. If the outflow frequency of this Karman vortex coincides with the natural frequency of the object, the amplitude increases more than the resonance phenomenon. This resonance phenomenon is called Karman vortex excitation.
Research Introduction
Vortex excitation
高流速ウォータートンネルにおけるNecklace渦の消失原因の解明円柱/平板系における縦渦励振の振動挙動の解明
流れによる発電技術の開発
十字交差円柱・平板系における縦渦励振現象に及ぼす円柱長さの影響
Vortex wind turbine, water turbine
Numerical study of the longitudinal wind/water turbine縦渦により駆動される円柱翼型風車・水車の動力特性の解明
Main facilities
- Wind tunnel
- High flow velocity water tunnel
- Visualization Water Tunnel
- Circulating water tank
- High speed camera
- Smoke generating device