S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Architecture and Architectural Engineering (건축학과) Journal Papers (저널논문_건축학과)
Multi-level approach for parametric roll analysis
- Kim, Taeyoung; Kim, Yonghwan
- Issue Date
- SOC NAVAL ARCHITECTS KOREA
- INTERNATIONAL JOURNAL OF NAVAL ARCHITECTURE AND OCEAN ENGINEERING; Vol.3 1; 53-64
- Parametric roll; Impulse response function; Rankine panel method; GM variation; Motion stability; Difference-frequency effect
- The present study considers multi-level approach for the analysis of parametric roll phenomena. Three kinds of computation method, GM variation, impulse response function (IRF), and Rankine panel method, are applied for the multi-level approach. IRF and Rankine panel method are based on the weakly nonlinear formulation which includes nonlinear Froude-Krylov and restoring forces. In the computation result of parametric roll occurrence test in regular waves, IRF and Rankine panel method show similar tendency. Although the GM variation approach predicts the occurrence of parametric roll at twice roll natural frequency, its frequency criteria shows a little difference. Nonlinear roll motion in bichromatic wave is also considered in this study. To prove the unstable roll motion in bichromatic waves, theoretical and numerical approaches are applied. The occurrence of parametric roll is theoretically examined by introducing the quasi-periodic Mathieu equation. Instability criteria are well predicted from stability analysis in theoretical approach. From the Fourier analysis, it has been verified that difference-frequency effects create the unstable roll motion. The occurrence of unstable roll motion in bichromatic wave is also observed in the experiment.
- Files in This Item: There are no files associated with this item.