Original scientific paper
https://doi.org/10.31217/p.40.2.1
CFD Analysis of a Stern Flap Effect on the Hydrodynamics of a Catamaran Ship
Ahmad Firdhaus
orcid.org/0000-0003-3642-7324
; Department of Naval Architecture, Faculty of Engineering, Diponegoro University, Semarang, Indonesia
*
Samuel .
orcid.org/0000-0001-9756-2402
; Department of Naval Architecture, Faculty of Engineering, Diponegoro University, Semarang, Indonesia
Muhammad Luqman Hakim
; Department of Naval Architecture, Faculty of Engineering, Diponegoro University, Semarang, Indonesia
Ocid Mursid
orcid.org/0000-0002-5171-3137
; Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, UK
Julian Raditya Putra
; Department of Naval Architecture, Faculty of Engineering, Diponegoro University, Semarang, Indonesia
* Corresponding author.
Abstract
Maritime transport is under increasing pressure to improve hydrodynamic efficiency and decrease emissions. catamarans offer operational benefits; however, they are limited by wave-making resistance at high speeds. Stern flaps are effective for monohulls, but their optimization for catamarans is inadequately investigated owing to the complexities of twin-hull hydrodynamics. this work utilizes computational fluid dynamics simulations to comprehensively assess stern flap performance on a catamaran under varying ship speed conditions and angles of attack. the findings indicate that a 0° flap decreases overall resistance by an average of 5.5%, despite a 1.76% increase in wetted surface area, accomplished by separation-free flow and balanced trim correction, which includes a 42% reduction in stern-squat at higher Froude numbers. conversely, a 20° flap elevates resistance by up to 8.8% at high froude numbers due to flow separation, which exacerbates a 4.48% increase in wetted area and a 0.49% rise in heave, despite its 93% geometric trim correction. research results indicate that neutral flap angles improve catamaran efficiency by avoiding three hydrodynamic drawbacks of higher angles: increased pressure drag, expanded wetted surface, and reduced stability. High-angle configurations are not recommended for any operating profiles.
Keywords
Catamaran; Stern Flap; Computational Fluid Dynamic; Ship Resistance
Hrčak ID:
346489
URI
Publication date:
23.4.2026.
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