Drag reduction for marine hull - has pressure controlled bubble layer provided under hull by air supply to perforated bulkhead

摘要

The front end of the hull is provided with a transverse duct under the waterline and with exist slots (38) through which a stream of bubbles forms a drag reducing carpet. The duct is divided into two halves by a perforated bulkhead (34) so that an even pressure control is achieved to provide an even carpet. The bulkhead ensures that a controlled airflow is achieved to the exit chamber (36) while distribution of the exit slots (38) to the water is greater with increasing depth and water pressure. A single air supply can be used with the duct geometry ensuring and even carpet.