A Study on the Estimation of the Form Factor of Full-Scale Ship by the Experimental Data of Geosim Models

Abstract

Generally, form factor is determined through ITTC method. Determining the form factor from ITTC method includes the assumption that the form factor of a full-scale ship is the same value as its model ship. In other words, the form factor is independent on Reynolds number. However, for the more appropriate prediction of the resistance performance of a full-scale ship, the form factor must be determined with the consideration of the variation attendant on Reynolds number. In this research, several Geosim ship models are adopted to investigate the scale effect, and correlation lines of form factor are improved to suggest the better extrapolation method for the prediction of the form factor of full-scale ship. The corrected form factors using the correlation lines are compared with those determined from the results of low-speed resistance tests. To consider the influence of hull form, the correlation lines are determined for the group of high-speed ships and the group of low-speed ships, respectively. The corrected form factors have shown good agreement among the prediction results from each Geosim ship model to the full-scale ship.

A Study on the Estimation Method of the Form Factor for a Full-Scale Ship

“…The predicted the effective power of the full-scale ships by this study were most similar because the correlation line of this study were classified as the differences in the hull forms used the numerical simulation results of the various Reynolds numbers from the model ship sizes to the full-scale ship. In the method reported by Ha et al (2013), the estimated effective A Study on the Estimation Method of the Seunng-Hee Lee, Sang Hyun Kim form factor for a full-scale ship 84 powers were more similar than the results estimated by the ITTC' 1978 method and Min and Kang (2010). The effective wake of a full-scale ship is needed to predict the delivered power.…”

“…10 and 11 were used in regression analysis. Regression analyses for an improvement of the method reported by Ha et al (2013) were performed according to the assumption and concept by Min and Kang (2013) The correlation lines of the form factors were suggested with each middle-low speed ships and high speed ships based on the design speed 20 knots. In this study, the model test data by García-Gómez (2000) and Min and Kang (2010) and the numerical simulation and model test data by this study were used in regression analysis.…”

“…In this study, the model test data by García-Gómez (2000) and Min and Kang (2010) and the numerical simulation and model test data by this study were used in regression analysis. The regression analysis results by Ha et al (2013) were applied to the exponential function but only the exponential function applied. In contrast, various functions were applied in the present study.…”

“…The principal dimensions of the ships, KVLCC2, KLNG and KCS are open to the public and can be found in Ha et al (2013) or elsewhere. Table 1 shows lists the design speeds of the ships and various scale ratios taken for the model tests and numerical simulations.…”

Fuel Consumption and CO2 Emission Reductions of Ships Powered by a Fuel-Cell-Based Hybrid Power Source

“…These values were scaled down for each operation mode and suitable load scenarios for each ship type were used. To utilize scale-down methodology, the linear interpolation method is applied [48]. For example, if the original 5500 TEU Reefer Container's rated power is 4154 kW, the rated power of the test bed is 180 kW, when applying the scale down method.…”