Journal article
URANS analysis of a broaching event in irregular quartering seas
Journal of marine science and technology, Vol.13(4), pp.395-407
11/2008
DOI: 10.1007/s00773-008-0022-5
Abstract
Ship motions in a high sea state can have adverse effects on controllability, cause loss of stability, and ultimately compromise the survivability of the ship. In a broaching event, the ship losses control, naturally turning broadside to the waves, causing a dangerous situation and possibly capsizing. Classical approaches to study broaching rely on costly experimental programs and/or time-domain potential or system-based simulation codes. In this paper the ability of Reynolds averaged Navier–Stokes (RANS) to simulate a broaching event in irregular waves is demonstrated, and the extensive information available is used to analyze the broaching process. The demonstration nature of this paper is stressed, as opposed to a validated study. Unsteady RANS (URANS) provides a model based on first principles to capture phenomena such as coupling between sway, yaw, and roll, roll damping, effects of complex waves on righting arm, rudders partially out of the water, etc. The computational fluid dynamics (CFD) method uses a single-phase level-set approach to model the free surface, and dynamic overset grids to resolve large-amplitude motions. Before evaluating irregular seas two regular wave cases are demonstrated, one causing broaching and one causing stable surf riding. A sea state 8 is imposed following an irregular Bretschneider spectrum, and an autopilot was implemented to control heading and speed with two different gains for the heading controller. It is concluded that the autopilot causes the ship to be in an adverse dynamic condition at the beginning of the broaching process, and thus is partially responsible for the occurrence of the broaching event.
Details
- Title: Subtitle
- URANS analysis of a broaching event in irregular quartering seas
- Creators
- Pablo Carrica - IIHR-Hydroscience and Engineering The University of Iowa 300 South Riverside Dr. Iowa City IA 52242 USAKwang-Jun Paik - IIHR-Hydroscience and Engineering The University of Iowa 300 South Riverside Dr. Iowa City IA 52242 USAHamid Hosseini - IIHR-Hydroscience and Engineering The University of Iowa 300 South Riverside Dr. Iowa City IA 52242 USAFrederick Stern - IIHR-Hydroscience and Engineering The University of Iowa 300 South Riverside Dr. Iowa City IA 52242 USA
- Resource Type
- Journal article
- Publication Details
- Journal of marine science and technology, Vol.13(4), pp.395-407
- Publisher
- Springer Japan; Japan
- DOI
- 10.1007/s00773-008-0022-5
- ISSN
- 0948-4280
- eISSN
- 1437-8213
- Language
- English
- Date published
- 11/2008
- Academic Unit
- Mechanical Engineering; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984064243602771
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