In-line and transverse forces on smooth and rough cylinders in oscillatory flow at high Reynolds numbers

摘要

This report presents the results of an extensive experimental investigation of thein-line and transverse forces acting on smooth, sand-roughened, and marine-roughenedcircular cylinders (k/D = 1/50) of identical length-to-diameter ratio (L/D = 2) placed in asinusoidally oscillating flow. The drag, inertia, and the maximum force coefficients havebeen determined through the use of the Fourier analysis. The transverse force (lift) hasbeen analysed in terms of its root-mean-square value. In addition, the amplitude of thefirst ten harmonics have been determined. The results are presented in both graphical andtabulated form in terms of the Reynolds number, Keulegan-Carpenter nunber, relativeroughness and the frequency parameter B (= Re/K).