振動流場における非対称没水構造物の方向抵抗特性に関する実験的研究

抄録

Directional characteristics of hydrodynamic force on a submerged asymmetrical roughness (we call this roughness BaNK block) in oscillatory flows were experimentally investigated. In this study, a quarter sphere or a half cylinder is used as a BaNK block which is set on the bottom of channel with an angle of attack θ to an oscillating flow direction. It is found that residual hydrodynamic force on half cylinder is much larger than that on quarter sphere because the substantial length of quarter sphere is smaller than that of half cylinder. Furthermore, residual hydrodynamic force on BaNK blocks is almost constant with the change of θ when Keulegan-Carpenter number KC is small. However, in large KC number, the force on quarter sphere decreases with the increase of θ because residual lift force decreases in θ=50°-90°.