水中で軸方向に振動する円柱の抗力係数と付加質量係数

概要

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Cylinders with various aspect-ratios and spheres, attached axially to a vertical spring, were vibrated longitudinally in still water by a vibrator which provided the top of the spring with a sinusoidal displacement. Then, the drag and added-mass coefficients were analysed by introducing the experimental values of amplitudes and frequency in the resonance into the solution of a spring-mass-damper system. First, to examine the validity of this method, the results on the spheres were compared with those by Sarpkaya, and both results proved to be in fairly good agreement. The results on the cylinders led to the following conclusions. There is a good correlation between those coefficients and Keulegan-Carpenter number K_c(=U_mT/D). A_S K_c. increases, the added-mass coefficient increases linearly and the drag coefficient decreases exponentially. When K_c exceeds about 10, the drag coefficient approaches the constant value. However, there is no clear correlation between these coefficients and Reynolds number.
一般社団法人日本機械学会の論文
1988-11-25