Drag and Inertia Forces on a Cylinder in Periodic Flow

Experimental results for the drag and added mass coefficients for a smooth circular cylinder in oscillatory flow are presented. The test results are correlated with the Reynolds number with the ratio of the amplitude of the motion to cylinder diameter as a parameter. The low Reynolds number results of Keulegan and Carpenter are replotted in this same format and together with the present high Reynolds number results give a fairly complete picture of the variation of the drag and added mass coefficients with Reynolds number for fixed values of the relative amplitude parameter. The results show that generally both the added mass and drag coefficients are highly dependent on the Reynolds number as well as the relative amplitude parameter. Above a Reynolds number of about 2 x 10⁵ the two coefficients become essentially independent of the Reynolds number.