Oscillations of cylinders in a linearly stratified fluid

The paper studies theoretically and experimentally hydrodynamic loads that act on horizontally placed cylinders of rhombic and square cross sections, oscillating harmonically in a linearly stratified fluid. An analytical solution is found with the use of affine similitude. Hydrodynamic force coefficients were evaluated experimentally from Fourier transforms of records of damped oscillations in a time–frequency region. It is shown that for polygonal contours, hydrodynamic loads change abruptly if the slope of the polygon sides coincides with the slope of the internal-wave group velocity vector.