Sprechtag "Hydrodynamic Performance of Energy Saving Devices"

Six Years Mewis Duct - Six Years of Hydrodynamic Development

Dipl.-Ing. Friedrich Mewis, Mewis Ship Hydrodynamics (MSH), Dresden, Germany

The Mewis Duct® (MD) is worldwide on of the most successful hydrodynamic Energy-Saving Devices (ESDs) of the last decade. The main hydrodynamic effect of the Mewis Duct® is the reduction of two complete independent energy losses around the running propeller behind ship – reduction of ship based wake losses and reduction of propeller based rotational losses in the slipstream.
Since its launch in 2008, the Mewis Duct® power saving device has experienced extraordinary success. To date over 550 have been delivered, with about 750 on order. Many model tests for the Mewis Duct® have shown an average power saving of 6.3%. Measurements in full scale confirm the power savings measured in model scale. The design of the Mewis Duct® is largely based on CFD-methods with model tests remaining a core element of the overall process.
The present paper shows an explanation of the working principles of the Mewis Duct®, further a comparison with other successful ESDs on the market. It is explained the design and optimisation philosophy, model test results and full scale results of projects with and without Mewis Duct® are shown and the combination of MD with other ESDs is discussed.