An Appraisal of Unconventional Aftbody Configurations and Propulsion Devices

Abstract

Recently, several additional devices and unconventional aftbody shapes have been applied to improve the overall efficiency of ship propulsion. These are Grothues spoilers, wake ducts, vane wheels, and asymmetric aftbody shapes. The paper describes the different physical mechanisms and specific features of the devices and configurations. Furthermore, theoretical and experimental data are presented regarding the gain in efficiency, based on calculations and model tests. Finally, experience with full-scale applications is reported.