Energy Saving Duct SILD
Sumitomo Integrated Lammeren Duct (SILD) is one of the most effective energy saving devices in the world which has been developed by Sumitomo Heavy Industries, Ltd. intending to install on slow speed large vessels such as tanker or bulk carrier.
The main advantage of SILD is as follows :
(1) reduce the ship resistance
(2) increase the wake gain
(3) produce the thrust
The effect of the SILD on reduction in resistance generally appears on the slow speed vessel with a high block coefficient. More than 2% of fuel savings will be achieved by this term. The wake gain can be increased by replacing the outer wake field by the inner wake field utilizing the duct accelerating/ decelerating effect. This effect also brings 2-3% of fuel savings. Moreover, the duct thrust will be generated by the oblique flow in the stern flow. This thrust can reduce the required propeller thrust, consequently the reduction of engine power. Through the several effect mentioned above, SILD can save the fuel oil by 5-8% totally.
The first SILD (6m Dia.) was installed on 280 type VLCC after checking the effect on hull vibration and maneuverability. The speed trial was conducted on Feb. 1996 and compared to the sister ship which has no SILD. Through the comparison, 6% power savings were confirmed by this actual ship trial data.
After the first installation of SILD on the VLCC, it is scheduled to install SILD on 95 type Aframax tanker and series of Panamax bulk carrier as a standard ship.
