높은 Reynolds수(1.0E5)에서의 원형단면 실린더 수직 강제진동에 대한 실험연구

Abstract

In order to investigate the effect of Reynolds number to load coefficients of marine slender structure in Vortex-Induced Vibration, forced oscillation experiments for circular cylinder were performed at the condition of 105 in Reynolds number (100 mm in diameter, 1.0 m/s in relative flow velocity) using carriage of towing tank. The rigid body cylinder model (600mm in length) was oscillated using a Scotch-Yoke type transversely forced vibration device. The hydrodynamic load was measured using 2-axis loadcell, and the motion of cylinder was measured using LVDT. The load coefficients were shown for two nondimensional parameters, nondimensional oscillation frequency and diameter ratio. Mean drag coefficients and oscillation drag coefficients were shown and compared with the results of Gopalkrishnans experiment(1993) at the condition of 104 in Reynolds number. The lift coefficients in phase with velocity and in phase with acceleration were investigated with Gopalkrishnans one(1993). Finally, the results were discussed and future study was presented.