Koji Hayashida

STUDY ON MECHANISM OF SEPARATION INTERFERENCE METHOD TO REDUCE AERODYNAMIC RESPONSE OF SQUARE PRISM

完全剥離型断面である正方形断面角柱を対象として，久保らが提案している剥離干渉法（Separation Interference Method）の空力的な耐風安定化の手法について，各種風洞実験から空力安定化に寄与するメカニズムの解明に関する検討を行った．その結果，剥離干渉法が有効に機能するためには，剥離点間で生じる循環流が重要な働きをしており，循環流によって生じる圧力分布の変化によって空力安定性の優劣が決定することを明らかにした．また，剥離干渉法が有効に機能している場合には剥離干渉後の流れは気流迎角の影響を受けにくいことを示した．

Separation Interference Method (SIM) to Reduce Aerodynamic Responses of Structures

The aerodynamic vibrations of bluff bodies are induced by separation flow from a leading edge of the bodies. Therefore, to suppress the separation from the leading edge is essential to reduction of the aerodynamic response amplitude. The authors developed one method and tried to make clear its suppression mechanism. The method is very simple. By using a plate that is placed to normal to the surface of the body at an optimum position, the separation flow from the leading edge is forced to touch the tip of the plate. The separation flow from the leading edge flows down without enrollment in the wake, then, the aerodynamic responses are reduced. The detail of the method and the reduction mechanism are described in the present paper, taking an instance of a square prism that vibrates within vortex-induced vibration region and galloping region. Both vibrations are suppressed by the method. The method was named by Y. KUBO, one of authors, as Separation Interference Method (SIM).Copyright