Paper detail

A Comparison of Model-Scale Experimental Measurements and Computational Predictions for a Large Transom-Stern Wave

The flow field generated by a transom stern hull form is a complex, broad-banded, three-dimensional system marked by a large breaking wave. This unsteady multiphase turbulent flow feature is difficult to study experimentally and simulate numerically. Recent model-scale experimental measurements and numerical predictions of the wave-elevation topology behind a transom-sterned hull form, Model 5673, are compared and assessed in this paper. The mean height, surface roughness (RMS), and spectra of the breaking stern-waves were measured by Light Detection And Ranging (LiDAR) and Quantitative Visualization (QViz) sensors over a range of model speeds covering both wet- and dry-transom operating conditions. Numerical predictions for this data set from two Office of Naval Research (ONR) supported naval-design codes, Numerical Flow Analysis (NFA) and CFDship-Iowa-V.4, have been performed. Comparisons of experimental data, including LiDAR and QViz measurements, to the numerical predictions for wet-transom and dry transom conditions are presented and demonstrate the current state of the art in the simulation of ship generated breaking waves. This work is part of an ongoing collaborative effort as part of the ONR Ship Wave Breaking and Bubble Wake program, to assess, validate, and improve the capability of Computational Fluid Dynamics (CFD).