Date of Degree
MS (Master of Science)
Surge Free Added Resistance testing in variable head wave conditions were completed for a container ship model. The added resistance experiments include calm water, head wave, and oblique wave cases with a focus on establishing a validation benchmark for CFD codes computing the added resistance and motions of the ship model during maneuvering. The ship used is a 1/85.19 scale KRISO Container Ship, KCS, model with a length of 2.70 m. Tests were performed at the IIHR wave basin. The 20 x 40 x 4.5 m wave basin is equipped with 6 inline plunger type wave makers and a 3 degrees of freedom carriage. A 4 degrees of freedom, surge, heave, roll, and pitch free mount with a mass spring damper system was used to tow the model. Calm water tests were performed for 13 Froude numbers between 0.0867 and 0.2817. The resistance coefficients, sinkage, and trim were found for each test. The calm water results were obtained and compared to results from towing tank facilities, with traditional mounts, to estimate facility biases at the IIHR wave basin. The results show that the size difference of the IIHR model and surge free motion create magnitude differences between facilities. Head and oblique wave tests were performed at Froude number 0.26 and wave height to wavelength ratio, H/λ, of 0.0167. For all wave tests, time histories of wave amplitude, resistance, and 4 DOF were measured. Fourier analysis was completed for all time histories of waves, forces, and motions and the 0th, 1st, and 2nd harmonic amplitudes and phases are presented. All head wave results are compared to other facilities data taken in a towing tank with a traditional mount. The data from all wave heading data was analyzed with a focus on the trends with incremented wave encounter angle. Most harmonic amplitudes show good agreement between all facilities, but removal of the small model used by IIHR shows even better agreement between facilities. The oblique wave heading data shows good agreement with the only other experimental oblique wave added resistance testing. Complete uncertainty analysis was completed for select cases for calm water, head wave, and oblique wave conditions. The uncertainty showed accurate data form most wavelength settings.
KCS, Oblique Wave Encounter, Surge Free Added Resistance
Copyright 2016 Mark Ryan Stocker