Model Test and Analysis on Oil Skimmers at Rough Sea (first report)

Abstract

In 1997, the Russian tanker “NAKHODKA” oil spill accident happened near the coast of Japan. The Japanese learned the dreadfulness of oil spills from this accident and realized the necessity of countermeasures. As the accident occurred in the Sea of Japan in mid-winter, the operation to recover the spilled oil was hampered by high waves. The biggest problem was the lack of equipment capable of recovering spilled oil, which had become highly viscous in the rough sea.Responding to this matter, the Association for Structural Improvement of the Shipbuilding Industry (ASIS) started an R&D project in fiscal year 1998 with grants from the Ministry of Transport to develop large equipment for the recovery of spilled oil in stormy weather (including the oil boom to gather spilled oil scattered over the sea, and the oil skimmer to recover spilled oil, both capable of functioning in stormy weather) to collect highly viscous oil with a minimum kinematics viscosity of 0.1m2/s (100, 000centi-stokes) in rough seas with a maximum wave height of 46meters.With regard to Oil Skimmers the following Research and Development was carried out.·Highly viscous oil sucking simulation of full- bore type jet pump.·Model tank test in water and in highly viscous oil to obtain the performance of full-bore type jet pump of oil skimmer.·Model tests using highly viscous oil on the Oil/Water Separator to obtain the performance and data.Consequently, the basic design of the Oil Skimmer and the Oil/Water Separator, which were most important components for an oil recovery system, were finalized according to the results of model tests.