乱流摩擦抵抗低減を目指した誘電エラストマによって実現される進行波状壁面の開発

抄録

A dielectric elastomer actuator was fabricated to realize a traveling wave-like wall that reduces turbulent friction drag. The actuator is rectangular, with one actuating part (electrode part) at one end of the rectangle, and the other parts are composed of elastomers only. The actuator was operated at high voltage, and the displacement was measured with a laser displacement meter. The results showed that the actuating part with electrodes on both sides of the elastomer showed a displacement of 100 μ m at the input frequency. This displacement was sufficiently more significant than the change in the thickness of the elastomer layer estimated from the Coulomb force acting between the electrodes and is thought to be the result of the elastomer sheet itself being deformed by the force of area expansion due to the constant volume of the elastomer. When the electrodes were operated at a higher frequency (100 Hz), the displacement was about 10 μ m. The vibration generated at the electrode part propagated downstream, and the 100 Hz vibration was dominant even at a position more than 100 mm away. The change in phase difference between the electrode part and an arbitrary position in the streamwise direction demonstrated the generation of a 100 Hz traveling wave.