Journal article
URANS analysis of a free-running destroyer sailing in irregular stern-quartering waves at sea state 7
Ocean engineering, Vol.237, p.109600
10/01/2021
DOI: 10.1016/j.oceaneng.2021.109600
Abstract
Computational fluid dynamics (CFD) simulations and stochastic validation of free-running 5415M in irregular stern-quartering sea state 7 and Froude number 0.33 are presented. Unsteady Reynolds-averaged Navier–Stokes (URANS) computations are validated against experimental fluid dynamics (EFD) tests. EFD static stability, forward speed, wave direction and spectrum were set such that roll-motion resonance were induced, causing large roll angles, significant deck-edge immersion, and static instability. Prerequisite calm-water validation covers roll decay at zero speed and self-propulsion studies for propeller RPM. Subsequent CFD stochastic validation is achieved by statistical assessment of EFD data and CFD results (expected value, standard deviation, and probability distribution) for input waves and ship response: time series are assessed by their wave energy-spectra, autocovariance (waves only), and block-bootstrap analysis (waves and motions); mean-crossing amplitudes are studied by bootstrap method. Dynamic mode decomposition is used with EFD and CFD time histories to unveil the underlying ship dynamics and the motion correlation. Overall, CFD results are in agreement with EFD. Finally, a clustering approach is used to identify wave sequences causing large roll angles. As proof of concept, the characteristics of these sequences are used for the deterministic reconstruction of severe (large roll) and rare (capsize) events via regular wave computations.
•Free-running URANS simulations of 5415M in irregular waves at sea state 7•Stochastic validation of CFD versus EFD for wave and ship-motion time series•DMD to unveil underlying ship dynamics and shed light on CFD and EFD differences•Clustering-based identification of conditions causing large roll angles•Deterministic reconstruction of severe and rare events by regular waves URANS computations
Details
- Title: Subtitle
- URANS analysis of a free-running destroyer sailing in irregular stern-quartering waves at sea state 7
- Creators
- Andrea Serani - National Research CouncilMatteo Diez - National Research CouncilFrans van Walree - Maritime Research Institute NetherlandsFrederick Stern - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Ocean engineering, Vol.237, p.109600
- DOI
- 10.1016/j.oceaneng.2021.109600
- ISSN
- 0029-8018
- eISSN
- 1873-5258
- Publisher
- Elsevier Ltd
- Grant note
- DOI: 10.13039/501100003693, name: Korea Institute of Science and Technology, award: 19026000, N00014-17-1-2083, N00014-17-1-2084; DOI: 10.13039/100000006, name: Office of Naval Research, award: 19026000, N00014-17-1-2083, N00014-17-1-2084; DOI: 10.13039/100008893, name: University of Iowa, award: 19026000, N00014-17-1-2083, N00014-17-1-2084
- Language
- English
- Date published
- 10/01/2021
- Academic Unit
- Mechanical Engineering
- Record Identifier
- 9984196506702771
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