Calculations of Wave Run-up on Cylinder in Multi-Directional Focused Waves

摘要

The present paper is concerned with the problem of estimating wave run-up on a vertical circular cylinder in an extreme wave environment. The waves are generated in a 3D wave basin using a focused wave method with different frequency and directional components. A practical method based on the velocity stagnation head theory (R_u = η_(max) + mu~2/2) is calibrated to calculate the wave run-up. The maximum wave kinematics at wave crest u is calculated using second-order theory. Wave run-up on the weather side of the cylinder is calculated and compared with measurements of wave run-up in experiments with multi-directional focused wave groups. The relations between defined parameter m and the wave parameters, such as model scale, directional spreading index and wave steepness, are discussed. The results reveal that these wave parameters have no significant influence on the value of coefficient m. An average value m = 3.25 is proposed for all experimental cases.