Improving the Predictions of Ship Speed and Fuel Consumption for Heavy Lift Vessels

Improving the Predictions of Ship Speed and Fuel Consumption for Heavy Lift Vessels

Burger, R.

van Terwisga, T.C.J. (mentor)

Mechanical, Maritime and Materials Engineering

Marine Technology

Ship Hydromechanics

2017-03-17

The current ship speed prediction at a given fuel consumption shows large differences with the actual operational values for the Happy Star. This can result in schedule fines, unexpected fuel expenditures and difficulties in bunker schedules. The first goal of this research is to improve these predictions for the expected range of weather conditions and expand it for cargo or no-cargo condition in good or bad weather. A second goal of this research is to gain insight in the uncertainty of predicting fuel consumption. A prediction model is built which takes into account the calm water, added resistance due to wind- and swell waves and added resistance due to wind. The total resistance follows from the sum of these separate components. The total resistance is translated to a value for daily fuel consumption. Using hind-casting a validation is performed with daily fuel consumption from noon reports. The uncertainties accompanied with these calculations are reported as well as the uncertainty propagation in the translation of resistance to consumed fuel. From the results of the simulations it seems justified to conclude that; 1. The separation of cargo/no-cargo conditions and good/bad weather gives an improved estimation the relation between vessel speed and daily fuel consumption, as expressed by the prediction error; a. For no-cargo condition from 79% to 60%/55% in good/bad weather respectively b. For cargo condition from 79% to 56%/60% in good/bad weather respectively 2. The goodness of the fit for no-cargo conditions is 63% while this is 32% for cargo conditions. This difference results from overhanging and high deck cargoes. 3. Wind resistance is the dominant resistance component after calm water resistance in all sailing conditions. In cargo condition during bad weather this contribution gets up to 32% of the total resistance comparing to 9% for wave resistance. 4. Following from the previous statement, the most important calculation parameters including highest uncertainty are the true wind angle, the wind load coefficient and true wind speed. Recommendations 1. In case of a long voyage with a large deck-cargo, BigLift should consider to perform a more extensive research on the wind resistance. 2. Monitoring of the following parameters would decrease the uncertainty in the calculations for fuel consumption; a. PTO enabled and how many power produced b. Combinator or fixed shaft frequency mode enabled c. A flow meter for the main engine only d. Automated measurements of shaft and break power

http://resolver.tudelft.nl/uuid:dd79c53c-9e9f-44f9-8d71-f981eba12798

Student theses

master thesis

(c) 2017 R. Burger