Hydrodynamic Forces on Submerged Oscillating Cylinders at Forward Speed

The hydrodynamic problem of submerged oscillating cylinders at forward speed is analysed by linearized potential theory. The numerical method used combines a finite-element approximation of the velocity potential in a region surrounding the cylinder with a boundary integral equation representation of the outer region. This method avoids the calculation of the second-order derivatives of the steady potential due to forward speed, which appear in the body surface condition for the unsteady potential due to the oscillation of the cylinder. Numerical results from the present method for test cases of a circular cylinder in an unbounded fluid and below a free surface are in excellent agreement with the analytical solutions. Further results for elliptic cylinders are provided and the influence of forward speed on the hydrodynamic force on a submerged cylinder is investigated.