Multicriterion Optimization of Stern Flap Design

Abstract

Stern flaps have been used in many recent designs of transom stern vessels to provide increased top speed or to realize improvements in fuel economy over the operating range. The use of stern flaps has also become a practical retrofit on existing designs because significant improvements can be achieved at very minimal cost. Model test data from a limited series of stern flap designs for a group of combatant type vessels were utilized to develop a preliminary design model for stern flaps for these vessels. This model has been incorporated into Visual VB/Microsoft Excel-based software that will permit the investigation of the benefits of stern flaps in preliminary design. Within the limitations of the model, this software will also perform the multicriterion optimization needed to establish the initial parameters for a stern flap in preliminary design. This preliminary design can become the baseline design for use in a subsequent model test program. The software will then accept the results of tests of a systematic stern flap family developed about the baseline design and create a project-specific response surface model that can be used in subsequent detailed design. The software can then be utilized again to provide multicriterion optimization of this project-specific model to establish final design parameters for the stern flap.