Numerical Prediction of Wave Drag of 2-D and 3-D Bodies under or on a Free Surface

The flow characteristics such as; wave drag, lift (if present in the case of 2-D), wave pattern, and pressure distribution around 2-D and 3-D bodies moving steadily under or on a free surface are investigated by 2 different boundary element methods. The iterative boundary element method (IBEM), which was originally developed for both 2-D and 3-D cavitating hydrofoils and ship-like bodies moving with constant speed under or on the free surface, is applied here in the case of a 2-D hydrofoil with an angle of attack, and some extended results are given. The effects of Froude number and the depth of submergence of hydrofoil from the free surface on pressure distribution and lift and wave drag values and the free surface wave elevation are discussed. The original method of Dawson, on the other hand, is applied to predict the wave pattern and wave drag values of fully submerged bodies (submarine) or surface piercing bodies (ship hull) in the case of 3-D. Some extensive numerical results are also shown to compare with those of experiments and other numerical methods in the literature.