摘要: |
Anticipating that near real-time estimates of ocean currents could feasibly be used to determine ship routes that would result in reduced fuel consumption, 360 voyages were simulated in the North Atlantic Gulf Stream region to investigate voyage characteristics leading to particularly high or low fuel savings. In the simulations, currents are the primary factor in determining the ship's course. Minimum fuel routes were determined for the currents, and the relative fuel savings of these routes were computed and compared to great circle routes. Ships that modified course slightly to take advantage of the positive effects of the currents had much larger savings than those that avoided the negative effects of contrary currents or went substantially out of the way to catch favorable flows. Determining where and how to cross the core flow was found to be more beneficial than trying to take advantage of the favorable or avoiding the unfavorable effects of rings that are shed from the core. The magnitude of the fuel savings, which often exceeded 10% in the study area, depended on the specific realizations of the dynamic current patterns when the voyages were conducted. Therefore, general rules balancing current-induced fuel consumption effects with weather- and wave-induced effects are probably not feasible, and explicit mathematical-based route analyses might be required to reap the benefits of ocean current routing. |