Toby Ratcliffe | Searcharxiv

arXiv2014

A Comparison of Experimental Measurements and Computational Predictions of a Deep-V Planing Hull

In order to support development of computational fluid dynamics codes for high-speed, small-craft applications, laboratory experiments were performed on a representative of Deep-V planing craft model. The measurements included resistance, sinkage and trim, hull pressure measurements, longitudinal wavecuts, and bow-wave and stern-wake topologies. The model was towed in calm water over a speed range of 1.78 to 14.2 m/s (5.8 to 46.6 ft/s) corresponding to a Froude number range of 0.31 to 2.5. At planing speeds, +8 m/s (+26.2 ft/s), the model was run with the addition of trim tabs set at two different angles, 7 and 13 degrees. Photographic documentation, including still photographs and video, was recorded during the collection of all the data. Numerical simulation of the flow field was performed utilizing the Numerical Flow Analysis (NFA) code and compared to the model test results.

physics.flu-dyn↗

arXiv2014

An Integrated Experimental and Computational Investigation into the Dynamic Loads and Free-surface Wave-Field Perturbations Induced by Head-Sea Regular Waves on a 1/8.25 Scale-Model of the R/V ATHENA

A 1/8.25 scale-model of the U.S. Navy Research Vessel ATHENA was tested in regular head-sea waves to obtain data for validation of computational fluid dynamics (CFD) predictive tools. The experiments were performed in the David Taylor Model Basin at the Naval Surface Warfare Center (NSWC). With the model towed fixed in head-seas, horizontal and vertical loads on the model were obtained at two Froude numbers, $F_r=0.25$ and $F_r=0.43$. The model was run at two conditions of head-sea wavelengths corresponding to $\lambda=2L_o$ and $\lambda=1/2L_o$ with $H/\lambda=0.03$, where $L_o$ is the length of the model and $H=2 a$ is the wave height. The wave field perturbations induced by the head-sea waves were quantified from free-surface images generated by a laser light sheet. Predictions of the horizontal and vertical loads on the model in regular head sea waves were made with the Numerical Flow Analysis (NFA) code. Numerical predictions of the wave-field perturbations were compared with the experimental data and the correlation coefficients have been computed.

physics.flu-dyn↗