Numerical Investigation into the Effect of Damage Openings on Ship Hydrodynamics by the Overset Mesh Technique

Abstract

Damage stability is difficult to assess due to the complex hydrodynamic phenomena regarding interactions between fluid and structures. Therefore, a detailed analysis of the flooding progression and motion responses is important for improving ship safety. In this paper, numerical simulations are performed on the damaged DTMB 5415 ship at zero speed. All calculation are carried out using CD Adapco Star CCM + software, investigating the effect of damage openings on ship hydrodynamics, including the side damage and the bottom damage. The computational domain is modelled by the overset mesh and solved using the unsteady Reynold-average Navier-Stokes (URANS) solver. An implicit solver is used to find the field of all hydrodynamics unknown quantities, in conjunction with an iterative solver to solve each time step. The Volume of Fluid (VOF) method is applied to visualize the flooding process and capture the complex hydrodynamics behaviors. The simulation results indicated that two damage locations produce the characteristic flooding processes, and the motion responses corresponding to the hydrodynamic behaviors are different. Through comparative analysis, due to the difference between the horizontal impact on the longitudinal bulkhead and the vertical impact on the bottom plate, the bottom damage scenario always has a larger heel angle than the side damage scenario in the same period. However, the pitch motions are basically consistent. Generally, the visualization of the flooding process is efficient to explain the causes of the motion responses. Also, when the damage occurs, regardless of the bottom damage or the side damage, the excessive heel angle due to asymmetric flooding is often a threat to ship survivability with respect to the pitch angle.

Numerical evaluation of a ship's manoeuvrability and course keeping control under various wave conditions using CFD

“…From the hole-cutting process, four types of cells are generated: 1) active cells, 2) passive cells, 3) donor cells, and 4) acceptor cells. Detailed information on the overset mesh methodology can be found in Zhang et al (2020). It is of note that creating the overlapping grids around the rudder is quite challenging due to the tight gap between the rudder blade and horn, whereas the overset grid generation around the ship hull is more straightforward.…”

Numerical and analytical assessment of hydraulic pressure on the inner wall of the deep-water caisson under sudden flooding risk

“…For the balanced case, the water level is calculated by equation (13). For the sudden sinking case, the water level during the sinking period is solved by equation (17), while it is calculated by equation (15) when the caisson is still. u is set to be 0.8 following the experimental validation mentioned above.…”

“…A coupled model was applied to calculate the interactive dynamics of floodwater and damaged vessels by many researchers, such as Woodburn et al, 15 Cho et al 16 and Zhang et al. 17 In the coupled model, the floodwater motion is calculated using the VOF method, while the vessel's motion is determined by the potential flow theory. Gao and Vassalos 18 used a RANS based CFD solver with VOF modeling of the free surface to investigate the effects of sloshing and flooding on damage ship hydrodynamics.…”

Stability and Seakeeping of Marine Vessels

“…The book Stability and Seakeeping of Marine Vessels includes nine contributions [1][2][3][4][5][6][7][8][9] to this Special Issue published during 2020. The overall aim of the collection is to improve knowledge about the most relevant and recent topics in ship stability and seakeeping.…”

“…Zhang et al (2019) [1] focus on the analysis of the effect of damage openings, specifically side and bottom damage openings, on the ship flooding process. The investigation is carried out numerically using the commercial CFD code CD Adapco Star CCM+, and the damaged hull investigated is the DTMB 5415 ship at zero speed.…”