Validation of potential flow method for ship resistance prediction

Abstract

Considering the extensive use of numerical methods in naval design, a question about the accuracy numerical tools that could estimate the flow around the ship and which are the limitations of these tools for practical design applications. In this context, experimental test on scaled models play an important role in validation of numerical simulations. This work is dedicated to validation of the method used to calculate the non-linear potential free-surface flow around the ship. Global quantities, as total resistance, wave resistance coefficient, residual resistance coefficient are flow characteristics concentrated in a single value, and their validation provides a criterion for choosing the optimum hull. Validation of physical phenomena is done using the wave profile, the pressure distribution on the body or the free surface topology. Validations were developed by comparing experimental data published for benchmark test cases, results of the resistance test performed in ICEPRONAV towing tank, against the results of numerical calculation performed by the author. Numerical simulations were performed using the XPAN module of the SHIPFLOW program, dedicated to the calculation of non-linear potential free-surface flow. Therefore, in order that the validation to be consistent and not influenced by scale effects, all calculations have been performed for the model scale. For this purpose, numerical studies have been considered for three ship models with different complex geometries. Two of the three hulls, the 60 Series and the DTMB 5415, are benchmark tests, chosen due to a wide range of detailed experimental and numerical results. The other one is case study for which experimental measurements were carried out in the frame of research projects.