March 6 - 8, 2017 | Berlin
LEADING ENGINEERING SIMULATION CONFERENCE
Full-scale self-propulsion calculations including roughness effects and validation with sea trial data
A number of studies into the physical modelling for the calculation of wake fields for ships with high block coefficient have been performed at ibmv. The models that are found to provide a good wake prediction are typically considered to be not suitable for ship resistance predictions.
In 2016 Lloyd’s Register was hosting the first workshop on ship scale hydrodynamics. This workshop offered an opportunity to perform so-called ‘blind’ power and speed predictions for a small bulk carrier and to compare the results with other participants and with full-scale measurements. For calculating speed and power both the wake and the resistance predictions are important. Therefore, this workshop provided an ideal test case to learn more about resistance predictions and to address the problem of the suitability of CFD-models for wake and resistance.
The approach followed is to use the models validated for wake predictions and to concentrate on a good representation of the propulsion and propeller-hull interaction. This result is then combined with a suitable resistance prediction. In order to have maximum flexibility with respect to the CFD models selected for the individual problems the setup was split into a resistance and a propulsion part.
The presentation will give an introduction to the test case and an overview of how the CFD-setup evolved. It will explain the motivation and address the main problems that had to be solved when selecting suitable approaches for physical and geometrical modelling. The computational results will be compared with the measured full scale data.