nan Renilson

The Formation of Surfable Waves in a Circular Wave Pool: Comparison of Numerical and Experimental Approaches

This paper investigates the capability of a numerical approach to address the problem of designing a wave pool. The numerical approach developed has the potential to reduce the number of design alternatives which require testing by eliminating poor performing designs early in the design cycle. For the three dimensional computations in the present study, the CFD software FLUENT (which solves the RANS equations with finite-volume approach and uses the volume of fluid technique to simulate the free-surface motion) was utilized. Pressure source models in straight and round tracks were simulated. Predicted results agreed closely with experiment data. Copyright

Influence of restricted water on the time domain interaction forces and moment on a berthed ship due to a passing ship

Abstract An investigation was conducted into the effect that different berthed ship bow and stern blockage arrangements has on the interaction forces and moment experienced by a berthed ship due to a passing ship. Physical scale model experiments were used to quantify the magnitude and form of the interaction forces and moments for five different blockage arrangements. The interaction force and moment traces from the experiments were compared to traces predicted using existing empirical formulae based on open water scenarios. Additionally, two methods were used to adjust idealised curves using the experimental results to better represent the form and magnitude of the interaction forces and moments. To demonstrate the effect that the changes in form and magnitude of the interaction forces and moments has on the predicted berthed ship motions the interaction forces and moment from the physical scale model experiments, empirical predictions and the adjusted idealised curves were extrapolated to represent a full scale ship and used as input to a commercially available time domain numerical simulation code to predict the berthed ship motions. The bow and stern blockage was shown to have a significant effect on both the form and magnitude of the interaction forces and moments, and hence, the predicted berthed ship motions. The empirically predicted interaction forces and moments correlated poorly with the experimental results.

Squat in Berthed Ship - Passing Ship Interaction for Restricted Water Cases

This paper presents a study on berthed ship – passing ship interaction for two different channel widths using physical model scale physical experiments and Computational Fluid Dynamics (CFD). The interaction forces and moment and the sinkage of the berthed ship were measured for the two different channel widths. In order to determine the effect that the additional blockage caused by the berthed ship had on the squat of the passing ship, the squat was also measured under the same conditions as in the ship interaction scenarios, but without the presence of berthed ship. The two restricted water cases were replicated in model scale using 3D inviscid double body CFD simulations and validated against experimental results. The CFD models were run with the passing ship fixed in the static level trim condition as well as with the passing ship fixed at the running sinkage and trim condition measured from the physical model scale experiments to determine whether the latter would improve correlation with the experimental results.