Simulation of freefall water entry of a finite wedge with flow detachment. (April 2017)

• Record Type: Journal Article
• Authors: Bao, C.M.; Wu, G.X.; Xu, G.
• Is Part Of: Applied ocean research. Volume 65(2017)
• Page Start: 262
• Page End: 278
• Publication Date: 2017-04
• Subjects: Oblique water entry -- Boundary element method -- Flow detachment with free jet -- Free fall motion -- Multi degrees of freedom -- Auxiliary function; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2017.04.014
• Languages: English
• ISSNs: 0141-1187

Abstract

Highlights: Oblique water entry of an asymmetric finite wedge with rotation in freefall is considered. The coupled and multi-degree complex motions of a body during water entry is simulated. The center of the body mass has important implications to the motion character. Abstract: A two-dimensional finite wedge entering water obliquely in freefall with three degrees of freedom is considered through the velocity potential theory for the incompressible liquid. The problem is solved by using the boundary element method in the time domain. The scheme of the stretched coordinate system is adopted at the initial stages when only a small part of the wedge near its tip has entered water. The auxiliary function method is adopted to decouple the nonlinear mutual dependence between the body motions in three degrees of freedom and the fluid flow. When the liquid has detached from the knuckle of the wedge, the free jet is treated through the momentum equation. The developed method is verified through existing results for one degree of freedom in vertical motion. Various case studies are undertaken for a wedge entering water vertically, obliquely and with rotational angles. Results are provided the accelerations, velocities, pressure distribution and free surface deformation, and the physical implications are discussed.