Numerical investigation of local field bow wave by AMR_based CFD method

Bow wave is generally associated with the breaking wave phenomenon, which has attracted much attentions. To figure out the mechanism and the relationship between local field bow wave and wave breaking phenomenon, numerical simulation is conducted by CFD (computational fluid dynamic) with the introduction of UAMR (user defined adaptive mesh refinement). Before the analyses of the flow field, relevant validations are initially carried out. With validated flow field, local field bow is investigated by velocity vector analysis, where the discontinuity of the flow beneath bow wave is observed. Based on Q-criteria vortex recognition method, vortex motion towards downstream wake field is clearly discovered. Velocity head loss contour, of which the distribution range exceeds the ship width, further proves the momentum loss evolution from nonlinear bow wave. Therefore, the energy translation of nonlinear bow wave is confirmed in the nonlinear bow wave. Considering no obvious wave breaking phenomenon is observed in present simulation, nonlinear properties instead of breaking phenomenon itself should be the most important feature in local field bow wave. The present research could be helpful for further understanding the physical mechanism of local field bow wave and their contribution to total resistance.